Construction plan for instrument engineering projects

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Construction Plan for Instrumentation Projects 1. Basis for Preparation 1.1.1、The tender documents for this project； 1.1.2, Code for Construction and Acceptance of Automatic Instrumentation Projects GB50093-2002 ； 1.1.3, \"Quality Inspection and Evaluation Standards for the Installation of Automated Instrumentation Projects\" GBJ131-90 ； 1.1.4, \"Technical Regulations for Petrochemical Instrumentation Engineering\" SHJ521-91 ； 1.1.5, \"Installation Manual for Automatic Control Instruments\" HG/T 21581-95 ； 1.1.6, \"Technical Specifications for the Construction of Petrochemical Instrumentation Projects\" SH3521-1999. 2. Construction preparation: 1.1.7, 2.1 All major construction tools, testing equipment, standard instruments, etc. required during construction must be properly prepared. 1.1.8 The owner is responsible for providing the drawings required for Projects 2.1.8 and 2.2, as well as the technical documents necessary for the installation and commissioning of the instrumentation and equipment. The construction unit shall be responsible for the receipt, dispatch, and storage of all drawings and technical documents. All drawings and documents must be obtained through proper procedures for retrieval or borrowing. Once borrowed, they should be returned to the document management department in a timely manner; no drawings or technical documents shall be lost or disclosed to outsiders. Carefully review the drawings with relevant professionals to identify various issues in the design in a timely manner, thereby creating favorable conditions for construction. Before the construction begins, the project owner or supervision unit organizes a design briefing and a review of the drawings. Engineering and technical personnel should provide safety and technical briefings to all personnel involved in the construction. 1.1.9, 2.3 Inspection and acceptance of equipment materials: The storage of instrument equipment from its arrival until unpacking is generally the responsibility of the owner. Upon receiving notification, relevant parties should cooperate actively with the owner to organize the unpacking, inspection, and acceptance of the equipment. During acceptance, it is necessary to check whether the packaging and sealing are in good condition; conduct an external inspection after opening the package, verify that the quantity matches the list, ensure that the specifications and models conform to the design requirements, confirm that all accessories and spare parts are present, and check for the presence of product manuals and quality certification documents. A record of the unpacking process should also be kept. The accessories and instruction materials for each instrument should be properly stored for handover. The model specifications and hole positions of the cabinets and all their components must correspond to the design requirements; the surface of the cabinets should be flat without any deformation, and the paint coating should be in good condition. The procurement of installation materials shall be carried out in a unified manner; private procurement and use are strictly prohibited. For self-purchased materials, it is necessary to compare options from various suppliers before making a purchase; choose manufacturers and suppliers with good quality and a solid reputation. The names of the manufacturers along with samples should be provided to the owner for review and approval, and only after approval can bulk purchases be made. Upon the arrival of the materials, they should be submitted for inspection to the supervision unit in a timely manner; installation can only proceed after the inspection is successful. After receiving the materials for instrument installation, check whether their appearance is good, and whether they come with certificates of conformity and warranty documents. After receiving the materials for instrument installation, they should be arranged neatly by category. The instrumentation field makes use of a wide variety of materials, including many small components and accessories, which can easily lead to confusion and loss. Therefore, the materials stored in the warehouse should be organized neatly in categories and properly labeled, so as to facilitate easy access during construction. The issuance and storage of radioactive measuring equipment must comply with ** or the local regulations and rules governing radioactive materials. During the inspection, if any issues are detected, they must be reported in writing to the relevant departments for handling immediately. For instruments and equipment that are awaiting individual testing, or for those for which the individual testing has been completed and preparation for installation is underway, they must be stored in a proper manner indoors or in containers, in accordance with the specified storage conditions. 3. Installation of source components 3.1 General requirements for installation 1.1.10, 3.1.1 The welding for the installation of source components shall be carried out by the professionals in charge of process pipelines and equipment, and must meet the following requirements. 1.1.11, 3.1.2 The materials of the components from which the fluid is taken and their installation locations shall meet the design requirements, and they shall be installed simultaneously with the fabrication and installation of the equipment and pipelines. 1.1.12, 3.1.3 The drilling and welding of access components installed on process equipment or pipelines must be carried out prior to the anti-corrosion treatment, lining, and pressure testing of the equipment or pipelines; mechanical drilling is preferred for creating these openings. Source components installed on masonry and concrete should be embedded at the time of masonry or casting, or installation holes should be pre-provided. 1.1.13, 3.1.4 After the source components have been installed, pressure testing should be carried out on them along with the process equipment and pipelines. 3.2 Temperature sensing element: When installed perpendicular to the process pipeline as specified in 1.1.14 and 3.2.1, the axis of the sensing element shall intersect the axis of the pipeline perpendicularly. The installation of the expansion pipe shall comply with the design requirements. When installing at pipe bends, as per 1.1.15 and 3.2.2, it is necessary to do so in the opposite direction of the material flow, with the axis of the source component aligned with the axis of the process pipe. 1.1.16, 3.2.3 When installed at an angle to the pipeline, the axis of the source component should intersect the axis of the process pipeline in the direction opposite to the flow of the material. 3.3 Pressure tapping components: 1.1.17, 3.3.1 The installation location of pressure tapping components should be in a place where the flow of the material being measured is stable, and their ends should not extend beyond the inner walls of the equipment or pipes. When installed on the same pipe section as the temperature sensing element, it should be placed on the upstream side of the temperature sensing element. 1.1.18, 3.3.2 When installing pressure-taking components on masonry structures, the area around the pressure-taking pipes should be tightly filled with refractory fibers, and then sealed with refractory mortar. 1.1.19, 3.3.3 When measuring the pressure of turbid materials containing dust, solid particles, or precipitates, on vertical and inclined equipment and pipelines, the sensing element should be installed at an upward angle; on horizontal pipelines, it should be installed at an acute angle in line with the direction of the material flow. 1.1.20, 3.3.4 When measuring the pressure of liquids, vapors, and condensable gases at temperatures above 60°C, the sensing element of the pressure gauge installed on-site shall be equipped with an annular or U-shaped condensation elbow. 1.1.21, 3.3.5 When installing on horizontal and inclined pipes, the location of the pressure measurement points shall comply with the following requirements: When measuring gas pressure, it should be in the upper half of the pipe ； When measuring liquid pressure, in the upper half of the pipeline, within an angle range of 0–45° relative to the horizontal centerline of the pipeline ； When measuring steam pressure, it is taken in the upper half of the pipe, as well as in the lower half within an angle range of 0–45° from the horizontal centerline of the pipe. 3.4 Flow measurement components 1.1.22: When installed on horizontal or inclined pipes, the location of the pressure tapping points shall comply with the following requirements: When measuring gas flow, it should be in the upper half of the pipe ； When measuring liquid flow rate, in the upper half of the pipeline, within an angle range of 0–45° relative to the horizontal centerline of the pipeline ； When measuring steam flow, it is taken in the upper half of the pipe, as well as in the lower half within an angle range of 0–45° from the horizontal centerline of the pipe. 1.1.23 When using individually drilled corner ports for pressure tapping on orifices or nozzles, the distance between the axis of each pressure tapping port and the upstream and downstream end faces of the orifice or nozzle should be equal to 1/2 of the diameter of that pressure tapping port. The axis of the pressure tap should intersect perpendicularly with the axis of the pipeline. 1.1.24 When flange-type pressure taps are used for orifice plates, the distance between the axes of the pressure tap holes on the upstream and downstream sides and the end faces on those same sides shall comply with the relevant provisions of the construction and acceptance specifications. The axis of the pressure tap should intersect perpendicularly with the axis of the pipeline. 1.1.25 When using D or D/2 for pressure tapping on the orifice plate, the distance between the axis of the pressure tapping holes on the upstream and downstream sides and the end faces of those sides shall comply with the relevant provisions of the construction and acceptance specifications. The axis of the pressure tap should intersect perpendicularly with the axis of the pipeline. 1.1.26 When using pressure taps with equalizing rings, the taps should be evenly distributed across the same cross-section, and the number of taps on the upstream and downstream sides must be equal. 1.1.27 The axis of the sensing element of flow measurement devices such as pitot tubes, venturi pitot tubes, and average velocity tubes must intersect perpendicularly with the axis of the pipeline. 3.5 Level sensing elements 1.1.28: The installation location should be chosen in a place where the level changes are detectable easily, and where the sensing elements are not subject to impact from the material. 1.1.29 When a guide device is used with an internal floating ball level gauge or a float level gauge, the guide device must be installed vertically and the liquid flow must be unobstructed. 1.1.30 Before installation, a two-chamber balanced container should have its dimensions verified, and the integrity of the internal pipes should be checked. It should be installed vertically, with its center point aligned with the normal liquid level. The single-chamber equilibrium vessel should also be installed vertically. 1.1.31 The flange stub for installing the float-type level gauge must ensure that the float can move freely throughout its full range of operation. 1.1.32 The measuring tube of the electric contact level gauge should be installed vertically, and the installation location of the sensing element of the hydrostatic level gauge should be far away from the liquid inlets and outlets. 3.6 The analysis sampling points specified in 1.1.33 should be located in areas where pressure is stable, where changes in the actual composition can be detected accurately, and where representative analysis samples can be obtained. The vicinity of these sampling points should be free from laminar flow, vortices, air infiltration, dead zones, material blockages, or chemical reactions that are not part of the normal production process. 1.1.34 When installed on horizontal and inclined pipes, the installation orientation shall be the same as that of the pressure tapping component. 1.1.35 When the gas to be analyzed contains solid or liquid impurities, the elevation angle between the axis of the sampling component and the horizontal line should be greater than 15°. 4. Installation of instrumentation equipment 4.1 General provisions for instrument installation 1.1.36 Since the instruments produced by different manufacturers vary, this plan only specifies the general requirements for instrument installation. Therefore, before installation, it is necessary to thoroughly understand the technical specifications and installation requirements of the instruments by referring to the design documents and the instrument installation instructions before proceeding with the installation. 1.1.37 All instruments shall be installed only after passing the single calibration test. Construction must strictly follow the designed instrument installation diagrams, with proper selection of connection fittings and materials. Compare with the design drawings to check that the instrument tag numbers, models, specifications, materials, accessories, and measurement ranges are all correct. 1.1.38 The instrument should not be subjected to impacts or vibrations during installation. After installation, the instruments should be secure and level. 1.1.39 The display instrument should be installed in a location where the readings can be easily observed. The installation of all on-site instrumentation equipment should take into account ease of operation, maintenance, and repair. Instrumentation equipment should be avoided in locations with high dust levels, vibration, corrosion, humidity, or susceptibility to mechanical damage, as well as in environments with strong magnetic field interference, high temperatures, or extreme temperature fluctuations. 1.1.40 Flowmeters, control valves, primary components, etc., that are installed directly on the process pipelines should be installed after the pipelines have been purged successfully and prior to pressure testing; after installation, they should undergo pressure testing along with the equipment or pipeline system. The flow direction of the medium should be consistent with the arrow direction on the table body. 1.1.41 The wiring must be correct; after the field instruments are installed, designated and clearly visible nameplates should be firmly attached in locations where they can be easily observed, and appropriate protection should be provided to prevent contamination or damage. 1.1.42 When testing the insulation resistance of instruments or circuits, care should be taken to prevent damage to electronic devices or components. 1.1.43 The wiring entry points on instruments and junction boxes should not face upward; when this is unavoidable, sealing measures must be taken, and the box covers and entry points should be closed promptly. 1.1.44 During the construction process, the contractor is responsible for providing effective protection for the installed equipment and materials. To prevent contamination or damage to the instruments after installation, pressure gauges and bimetallic thermometers should retain their original foam plastic protective boxes ； The instrument protection box and wiring box can be wrapped with plastic film ； For other flow and level transmitters, control valves, etc., wooden protective boxes should be made when necessary to protect their gauges from damage. 1.1.45 Instruments that require degreasing according to regulations should be installed only after passing the degreasing inspection. 4.2 Installation of panel cabinets 1.1.46, Fabrication and installation of cabinet foundations: (1) The dimensions of the foundation for the panel cabinets should match those of the cabinet bases; during installation, its upper surface should be level with the floor, and the panels are connected to each other using bolts. The channel steel of the support plate foundation is fixed to the embedded iron components by welding (if no embedded iron components are available, expansion bolts can be used for fixation). The channel steel for the base plate must be leveled and straightened before being fixed. The properly installed foundation channel steel should be treated to prevent corrosion. The allowable deviations for various inspection items related to the installation of channel steel in dashboard cabinets are shown in the table below: Inspection Item, Quality Standard, Inspection Method. For straightness: t per meter; allowable deviation is 1 mm. To determine this, use a pull line or a set square to measure at the point of maximum deviation. If the total length is greater than 5 meters, the allowable deviation is 5 mm. For horizontal inclination: t per meter; allowable deviation is 1 mm. Measurement is carried out using a pull line, a level, or a spirit level. When the total length is greater than 5 meters, the allowable deviation is 5 mm. For position error and lack of parallelism: the allowable deviation is 5 mm over the entire length; measurement is done using a steel tape measure. 1.1.47 Transportation and Lifting: (1) Dashboard cabinets, as well as DCS equipment such as cabinets and control panels, should be packaged when leaving the factory. During transportation, it is necessary to use smooth and obstacle-free routes, and the speed should not be too high to avoid severe impacts and vibrations. Lifting should be supervised by qualified professional lift operators, and smoothness must be maintained during lifting and handling. 1.1.48 Unpacking inspection: Dashboards, cabinets, and control panels are precision electronic devices; unpacking inspection, transportation, and installation must all be carried out in accordance with construction specifications, design requirements, and the provisions of the product manual. The unpacking inspection of the cabinet shall be carried out jointly by the representative of the manufacturer, together with the supervisor and the relevant technical personnel from the owner, and an inspection record shall be signed after the inspection. Before opening the equipment, check whether the outer packaging is intact. After opening it, inspect for any damage to the packaging, the presence of water accumulation, and whether the moisture and water protection measures are in place; also check for any indicators designed to prevent tipping or vibration. When opening the equipment, appropriate tools should be used to remove the components in a sequential manner; violent knocking is strictly prohibited to avoid damaging the components on or inside the cabinet. The anti-corrosion coating on the surface of the cabinet should also be intact. The unpacking inspection involves checking each item against the packing list; the quantity, model, and specifications of all hardware, spare parts, and accessories must match those listed on the packing list. The equipment’s appearance is in good condition, and the outer packaging of the software media is intact. All necessary documents are available, including the user manual, system operation manual, installation manual, software configuration manual, hardware layout diagrams, arrangement diagrams, I/O address allocation table, and list of programs. 1.1.49 Cabinet installation: The cabinets are installed in the instrument control room, and their installation location shall be in accordance with the construction drawings. Cabinets far from the door should be entered first. The installation of the panel cabinets should proceed from far to near, and the floor must not be damaged when moving them within the control room. Before installation, lay a temporary access path from the entrance to the control room cabinets to the base area of those cabinets using planks or wooden scaffolding; the height of this path should be equal to the elevation of the top surface of the steel beams forming the base of the instrument cabinets. To prevent vibration when the cabinets are moved and to protect the floor surface, rubber sheets with a thickness of δ=10mm can be laid on the walkways. The cabinet is transported from its storage location to outside the control room, directly placed on the rollers located on the passageway, and then gently moved into position. The sequence for bringing the cabinets into the building and installing them is from the inside outward; that is, the equipment located further away from the entrance is installed first, while the equipment closer to the entrance is installed later. After all the dashboards have been moved to their installation positions, align and fix them together. The cabinet should be installed vertically, levelly, and firmly, with bolts used to connect each tray to the next. All fastening materials shall be rust-resistant materials, such as galvanized or nickel-plated ones. The allowable deviations for the inspection items of cabinets and the corresponding inspection methods are shown in the table below: Serial Number, Inspection Item, Allowable Deviation, Inspection Method. t1: Verticality of t (/m), t1.5mm; measured using a plumb line and ruler on the front and side surfaces of the cabinet. t2: Height difference between the tops of adjacent cabinets, t2mm; measured by pulling a string across the top of the cabinets or using a level and ruler. t3: Maximum height difference between cabinet tops (when there are more than two connections between cabinets), t5mm; measured by pulling a string across the top of the cabinets or using a level and ruler. t4: Flatness of the front surface of the cabinet, t1mm; measured from the surface of the cabinet using a plumb line from the top, middle, and bottom; applicable when there are more than five connections between cabinets. t5: Gap at the joints between cabinets, t2mm; measured using a feeler gauge. Note during installation: Transportation should not take place on rainy days, and the ambient temperature should be above 4°C ； The enclosure’s outer protective cover cannot be removed before it is installed and fixed in a centralized manner ； During handling and installation, the panel cabinets should be protected from severe vibrations. Deformation and damage to the surface paint should be prevented. After the cabinets are installed, it is necessary to lay the random cables (system cables) and carry out wiring adjustments as well as grounding of the cabinets. The connections of network communication cables and similar components shall meet the requirements specified by the manufacturer and the system design specifications, and the grounding resistance shall comply with the design requirements. Once the cable installation is complete, the wall openings for the incoming and outgoing cables should be sealed with explosion-proof putty or cement. Cabinet wiring should be carried out within wiring troughs, and the labels at both ends of the wiring must be correct, clear, and resistant to fading. When connecting wires to terminal blocks or device components, they should be arranged neatly and uniformly, with an appropriate amount of slack left. 4.3 Installation of temperature instruments 1.1.50: The temperature sensing elements should be installed at locations where the temperature of the medium can be accurately measured. Those installed in process pipelines should be perpendicular to the pipeline’s centerline or at a 45-degree angle; if inclined, the angle should be in the opposite direction to the flow direction, with the top of the element being positioned at the center of the pipeline. The sensing surface of the surface thermometer must make close contact with the surface of the object being measured, and it should be secured firmly. 1.1.51 When the temperature sensing element is installed in a location subject to severe impact from the material being measured, or when it is installed horizontally at a depth of more than 1 m or when the temperature to be measured is greater than 700°C, measures should be taken to prevent bending. The installation of capillaries should be protected, with a bending radius of not less than 50 mm. 1.1.52 The model of the compensation wire must match the calibration code of the thermocouple and the instruments connected to it; the total resistance of the circuit, including the thermocouple, should be within the range of circuit resistance allowed by the associated instruments. Compensation wires should be placed in protective tubes or laid in cable trays; they must not be laid in the same protective tube as other circuits. 4.4 Installation of pressure instruments 1.1.53: Pressure instruments should not be installed on equipment and pipelines that experience significant vibration. When there are large fluctuations in the pressure of the medium flowing through such instruments, measures should be taken to provide cushioning and increase damping. 1.1.54 When installing low-pressure and micro-pressure gauges, efforts should be made to minimize the impact of the height difference of the liquid column on the instrument’s measurements. The installation height of the pressure gauge or transmitter used to measure low pressure should be the same as the height of the pressure sampling point. 1.1.55 For pressure gauges installed on high-pressure equipment and pipelines, if they are located near the operation area, their installation height above the ground should be at least 1.8 meters; otherwise, a protective cover should be placed in front of the gauge. 1.1.56 For pressure measurement in corrosive media, an isolation vessel must be used, with facilities for draining and filling the isolation fluid installed at the highest and lowest points of the pipeline respectively. The isolation fluid should be pressed in from the bottom to facilitate the expulsion of gas from the pipeline. 4.5 Installation of Throttling Devices 1.1.57 Throttling devices include various types of orifice plates, nozzles, Venturi tubes, etc. The pipeline conditions and technical requirements for its installation shall comply with the provisions of the current **standards (GB2624-81) and the standards set by the Metrology Bureau (JJB267-81). The throttling component must be installed after the pipeline is flushed and cleaned. 1.1.58 Before installing the throttling device, inspections should be carried out on its appearance and bore diameter; the orifice plate, the inlet edge of the nozzle, and its inner walls must be smooth, free of burrs, scratches, or any visible damage. The sharp edges of the orifice plate and the curved surfaces of the nozzle should face the flow direction of the medium, and the straight pipe section ahead should meet the design requirements or construction specifications. Check that the material, thickness, and inner diameter of the gaskets used meet the design requirements. 1.1.59 Before installing the throttling element, it is necessary to check the roundness of the pipe over a length equal to 2 times the pipe diameter in the straight sections upstream and downstream of it. The measured roundness in the upstream straight section shall not exceed ±0.3% of its arithmetic average, while that in the downstream straight section shall not exceed ±2% of its arithmetic average. The roundness and straightness of pipes longer than 2 times the pipe diameter are inspected visually. 1.1.60 The installation of the throttling elements placed in the pipes shall be carried out in coordination with the process pipes; their front surfaces must be perpendicular to the pipe axis, with a deviation of no more than ±1°. The opening of the throttle element should be coaxial with the pipe, and the deviation from coaxiality shall not exceed 0.025d/(0.1+2.3β4), where β=dk/d, dk is the diameter of the orifice, and d is the inner diameter of the pipe. 1.1.61 The inner diameter of the sealing gasket for the throttle element should not be smaller than the inner diameter of the pipe. The sealing gasket of the throttling element must not press tightly against the inner wall of the pipe after clamping. 1.1.62 When a throttling element is installed in a vertical pipe to measure liquid flow, the flow direction of the liquid must be from bottom to top. 4.6 Installation of flow meters 1.1.63: Instruments, components, and parts installed directly on industrial pipelines shall be installed in coordination with the process pipelines. The minimum length of the straight pipe sections upstream and downstream of the flow meter shall comply with the design requirements and the specifications in the product manual. 1.1.64 The flow meter should be installed after the process pipeline has been properly purged. If pre-installation is necessary, it should be removed before pipeline purging, and the inlet and outlet areas should be sealed to prevent foreign objects from entering. The flow direction of the medium should be consistent with the arrow direction on the table body. 1.1.65 The rotameter should be installed in a vertical pipeline free from vibration, with the angle between its centerline and the vertical line not exceeding 2°; the flow direction of the medium to be measured should be from bottom to top. The straight pipe section on the upstream side should be more than 2 times the pipe diameter. 1.1.66 The Weiba flow meter can be installed in horizontal and vertical pipes, but the axis of the meter must be horizontal, with the dial perpendicular to the ground. The flow direction of the medium under test must meet the installation requirements of both the filter and the flow meter, and it must first pass through the filter before reaching the flow meter. When installed in a vertical pipe, the flow direction of the medium should be from bottom to top. 1.1.67 The Venturi flowmeter shall be installed in conjunction with the work piping by the piping specialty team, and the lengths of the straight sections upstream and downstream shall meet the requirements specified in the product manual. 4.7 Installation of level gauges 1.1.68: The installation of level gauges shall be carried out in accordance with the designed installation diagrams and the product instructions. 1.1.69 The float level gauge should be installed such that the float remains vertical, at the height of the normal operating level or the dividing level at the center of the float. 1.1.70 Before installing a radioactive level gauge, a specific installation plan should be prepared in accordance with the product instructions, and installation should only take place after protective measures have been put in place. Clear warning signs should be in place at the installation site to prevent unauthorized personnel from approaching. The installation and calibration of radioactive instrumentation equipment must also comply with ** or local regulations and rules regarding the handling of radioactive materials; professional personnel should be responsible for the installation or guidance in its installation. 4.8 Installation of analytical instruments 1.1.71: Before installing analytical instruments, it is necessary to carefully read the product’s technical documentation, understand its performance characteristics and the key points regarding installation and calibration, before proceeding with the installation. 1.1.72 The location of the sampling points for analytical instruments should be such that there is no laminar flow, no air infiltration, and no chemical reactions, in accordance with the design requirements. 1.1.73 When installing the sampling system for analytical instruments, it is necessary to check whether the dust removal from the samples, as well as the treatment of harmful and interfering components, are properly carried out. 1.1.74 The installation location of the analyzer or sampling system should be as close as possible to the sampling point, and must comply with the requirements specified in the manual. 1.1.75 The venting of exhaust gases and the recovery of samples shall comply with the design specifications. 1.1.76 The alarm devices of gas detection instruments shall be installed on a panel or console that is easy to observe and maintain, and there shall be no strong magnetic fields in the surrounding environment. 1.1.77 The installation position of the detection probe should be determined based on the density of the gas being measured. Used to detect the density of gases with a density greater than that of air; the detector is installed at a height of 0.2 to 0.3 meters above the ground ； Gas detectors used to detect gases with a density lower than that of air should be installed above areas where leaks may occur. The enclosure of the detector’s wiring box should be reliably grounded. 1.1.78 The oxygen analysis instrument shall be installed and calibrated under the guidance of the manufacturer’s personnel. The instrument air, insulation steam, and backflush steam required for the analysis instruments are provided by the process engineers, with on-site service personnel assisting with the installation. 1.1.79 The installation of analytical instrumentation generally involves specific technical requirements. During installation, it is necessary to follow the design specifications, product manuals, and technical documents in order to meet these requirements as much as possible, thereby ensuring accurate measurements. 4.9 Installation of mechanical quantity measuring instruments 1.1.80 The installation of the load sensors in weighing instruments and the application of loads should be carried out after the weighing container along with all its components and connections have been installed. 1.1.81 The load sensors should be installed vertically, ensuring that their main axis aligns with the axis of applied load, thereby minimizing the effects of inclined and eccentric loads; the stress on each sensor should be uniform. 1.1.82 The connection between the weighing container and the outside should be a flexible connection. 1.1.83 The supporting surface and bottom surface of the sensor should be smooth, without rust, scratches, or debris. 1.1.84 The force-measuring instrument should be installed so that the force to be measured acts evenly on the force-receiving surface of the sensor. 4.10 Installation of transmitters, instrument boxes, and wiring boxes: 1.1.85 Transmitters and converters that are not installed in protective boxes can be directly mounted on columns made of 2″ galvanized steel pipes and steel plates; each column is 1.5 meters in length. They can be fixed in place using expansion bolts, or directly welded to the steel platform. The columns must be installed firmly, with their tops sealed off. All supports shall be protected against corrosion in accordance with the anti-corrosion specifications. 1.1.86 When selecting the installation location for the transmitter, it is necessary to meet the requirements for instrument installation as much as possible, placing it close to the instruments it is connected to, and installing it against a building or industrial pipe rack whenever feasible. 1.1.87 The connections between the positive and negative chambers of the differential pressure gauge or transmitter and the measurement pipeline must be correct; the inclination direction and slope of the pressure lead pipes, as well as the installation of the auxiliary containers, shall all comply with the design requirements. The capillaries of double-flange differential pressure transmitters are protected using small trough boxes, and the bending radius of the capillaries should be greater than 50 mm. 1.1.88 The installation location of the instrument protection box is shown in the schematic diagram. When selecting a location, it should be chosen in a place with sufficient lighting, good ventilation, and easy access for operation and maintenance; it should be placed near the process pipelines or equipment it is connected to, close to the components from which data is obtained, and can be installed against a building or industrial pipe rack. The instrument enclosures and protective boxes must be installed in a straight and secure manner, at a height of approximately 600 mm above the ground or platform. The supports for these enclosures should be sturdy and reliable, and they must also be treated to prevent corrosion. The allowable deviation for the verticality and levelness of the instrument panel is 3 mm each; when installed in rows, they should appear neat and orderly. 1.1.89 The instrument wiring box should be installed in a location that does not interfere with operations, personnel movement, or maintenance work. The height of the center of the box above the operating floor should be between 1.2 and 1.5 meters. The wiring inside the box must be accurate, and the wire labels should be complete and neat. 1.1.90 When the instrument protection box is installed in areas with high corrosion, its sealing performance must meet the requirements for use. The instrument protection box must be installed in a straight and secure manner; the brackets are made by welding 2″ galvanized steel pipes to steel plates. All brackets should be fabricated according to the drawings, with no arbitrary changes allowed. All supports shall be firm and reliable, and shall be protected against corrosion in accordance with anti-corrosion specifications. 1.1.91 The protective box brackets are fixed to the floor or wall using expansion bolts, or they can also be welded directly to the steel platform. 4.11 Installation of control valves, regulating valves, and actuators 1.1.92: When dispatching regulating valves, the manufacturer’s quality certificate must be verified. Check the contents on the nameplate as well as the packing, specifications, dimensions, material, etc., in accordance with the valve data sheet, and inspect all components. The control valve is installed by the process engineering team, while the instrumentation team is responsible for inspection, wiring, piping, and commissioning. 1.1.93 The control valve should be installed after the process pipeline has been properly purged. If pre-installation is necessary, it should be removed before pressure testing and purging of the pipeline, with the inlet and outlet sealed to prevent foreign objects from entering. The flow direction of the medium should be consistent with the arrow on the valve body. 1.1.94 The installation location of control valves should facilitate observation, operation, and maintenance. The actuator should be firmly fixed, and the operation handwheel should be in a position that facilitates operation. The mechanical transmission of the actuator should be flexible, smooth, and reliable across its entire length. The signal pipes of pneumatic and hydraulic actuators should have sufficient flexibility to avoid interfering with the operation of the actuators, and the installation position of hydraulic actuators should be lower than that of the controller. 1.1.95 Small-diameter control valves connected by threads must be equipped with removable movable connectors during installation. 1.1.96 The inlet and outlet positions of the solenoid valve must be installed correctly. Before installation, the insulation resistance between the coil and the valve body should be checked, and the measurement results must meet the requirements specified in the product’s technical specifications. 5. Installation of instrument pipelines 5.1 General provisions 1.1.97: Instrument pipelines include gas supply pipelines, measurement pipelines, sampling pipelines, isolation and purging pipelines, as well as accessories such as valves, fittings, and containers. 1.1.98 When fixing instrument pipes to supports, the horizontal spacing between steel pipes should be 1.00–1.50 m, while the vertical spacing should be 1.50–2.00 m. The horizontal spacing between copper pipes, plastic pipes, and cables should be 0.50–0.70 m, while the vertical spacing should be 0.70–1.00 m. 1.1.99 The bending of instrument tubes should be done by cold bending, and it must be formed in one go, without any dents or cracks. The bending radius of high-pressure steel pipes should be greater than 5 times the outer diameter of the pipe; the bending radius of plastic pipes should be greater than 4.5 times the outer diameter of the pipe; the bending radius of other metal pipes should be greater than 3.5 times the outer diameter of the pipe. The installation of instrument pipelines should avoid intersections and sharp bends of less than 90° as much as possible. 1.1.100 When installing stainless steel pipelines, iron tools must not be used, and insulating materials should be applied to isolate the supports. The piping is laid along the process pipelines and buildings, with an angle steel support installed every 2 meters; its height and location are adjusted as appropriate based on the actual conditions on site. For the blowing (washing) pipeline, its connection components should be correct, and the valves should be installed in positions that facilitate operation. When laying pressure transfer pipes for highly toxic and flammable media, detailed construction records must be kept, and clear markings must be applied to the pipes. 1.1.101 Before installation, carbon steel pipes must undergo surface anti-corrosion treatment; the inside of the pipes should be wiped with kerosene twice before they are sealed and set aside for use. 1.1.102 Since the bending quality of stainless steel thin-walled tubes has a direct impact on the quality of instrument pipeline installation and operation, in order to ensure construction quality, it is planned to use specialized tools for thin-walled tubes from the American company Rich. 1.1.103 When bending pipes with a dedicated pipe bender, it should be used correctly. The tube must fit tightly inside the die; it should be bent in one go, without being straightened first and then bent again. After bending, the tube should be free of cracks and dents. Special cutting tools should be used to cut the pipes, and the cut ends should be smoothed out using internal and external pipe file tools to ensure they are smooth without any burrs. 1.1.104 When the purging and pressure testing of instrument pipelines (including hydraulic, pneumatic, vacuum, and leak tests) are carried out together with process pipelines or equipment, the pressure testing requirements shall be those applicable to the process pipelines or equipment. Before the pressure test, the primary root valve and the secondary instrument valve should be closed. Whether it is a water pressure test or a gas pressure test, pressure must be released from the primary root valve in order to flush the pipes and prevent blockages in the pressure guiding tubes. When the pressure guiding pipe is pressurized simultaneously with the process pipelines and equipment (including hydrostatic testing and airtightness testing), the transmitter does not participate in the pressure testing. The pressure testing check meets the specification requirements; fill out the pipeline pressure testing completion form. 1.1.105 The welding of instrument pipes follows the same procedures as those for process pipes; the welders must be qualified after passing examinations and possess the expertise to weld special steel materials, in order to ensure construction quality. The welded surface should be smooth, free of slag and burrs. Welding work shall comply with the relevant provisions of the current **standard \"Code for Construction and Acceptance of Welding Works on Field Equipment and Industrial Pipelines\" GB50236-98. 1.1.106 The source components should be installed in conjunction with the process pipelines or equipment; for those that have already been welded, their installation quality must be checked and their positions verified. The axial position of the pressure tapping point should be selected on a straight pipe section, avoiding areas with eddies and dead zones. The pressure tapping tube shall not extend into the inner wall of the process pipeline to avoid the effects of eddies. When installed adjacent to the temperature sensing element, the pressure tap should be installed in front of the temperature sensing element. 5.2 Instrument measurement pipelines 1.1.107: The measurement pipelines should be as short as possible, and their location and height should facilitate maintenance. When connecting the instrument pipelines to the instruments, the instruments should not be subjected to mechanical pressure. The distance between the measuring pipe and equipment, as well as the surface of pipes or buildings, should not be less than 50 mm. 1.1.108 The pipelines for instrument measurement should not be buried; they should be laid on supports or trays, with a slope of 1:10 to 1:100 to facilitate drainage or waste removal. Protective sleeves should be installed at the points where the pipeline passes through walls or floor slabs. 1.1.109 The positive-pressure tube and negative-pressure tube for measuring differential pressure should be installed in locations with the same ambient temperature. When connecting the measurement pipeline to the glass tube micromanometer, a hose should be used. 1.1.110 The welders working on pressure pipelines such as measurement tubes and analysis tubes must be certified through examinations and possess the qualifications to weld stainless steel or special steels. 5.3 Instrument pneumatic signal piping 1.1.111: Pneumatic signal pipes shall be made of copper, stainless steel, or polyethylene and nylon tubing. During installation, intermediate joints should be avoided as much as possible; if they must be used, clamped types should be employed. 1.1.112 The main pipeline is constructed using galvanized welded steel pipes and fittings for connection. The air supply pipes, valves, and fittings must be cleaned; there should be no contaminants such as oil, water, or rust. The air supply branch pipe should be led out above the process air supply main pipe. 1.1.113 The gas signal pipes, as well as the gas supply pipes leading to the instruments after the filter pressure regulator, are made of φ6×1 red copper tubes; centralized gas supply is provided by an air distributor to various branch pipes. The φ6×1 red copper tube is cold-formed and connected using a collet joint. 1.1.114 When multi-core pneumatic cables are used for instrument air pipelines, installation and laying are relatively convenient. It can be laid along cable trays and supports; the methods for laying cables can be referred to. Pneumatic cable intermediate and terminal connectors shall be protected with rubber sheaths. 1.1.115 The ambient temperature during cable laying shall comply with the provisions in the product’s technical documents; care shall be taken to prevent damage to the cables during laying, and an appropriate amount of slack shall be left in the cables after laying. 5.4 Instrument air supply pipelines: 1.1.116 Galvanized steel pipes shall be connected by threading; shaped elbows shall be used at bends. When sealing with sealing tape or similar materials, such sealing materials must not enter the inside of the pipes. 1.1.117 Seamless steel pipes shall be joined by welding, and slag must not enter the pipe. 1.1.118 Drain valves should be provided at the end of the pipeline and at the liquid collection point. The outlet for the branch pipes on the horizontal main pipe should be located above the main pipe. 1.1.119 After the gas supply pipes have been installed, they should be purged using qualified instrument air. The purging process should start with the main pipes, followed by the branch pipes, and finally the pipes connected to various instruments, until the required standard is achieved. 1.1.120, Purge inspection. When tested with a wooden target coated in white paint, if there is no rust, dust, moisture, or other debris on the target within 1 minute, the purging is considered successful. 1.1.121 Before using the gas supply system, the gas pressure value should be set according to the design requirements. 6. Instrument pressure guiding pipelines 1.1.122: There are a wide variety of pressure guiding pipelines, as well as related processing fittings and components in terms of material, specifications, and models; they should be stored separately in appropriate categories, recorded, and distributed accordingly, and mixed storage is not allowed. Tubes, fittings, and processed components made of special materials should be labeled promptly upon being stored. 1.1.123 The bending of pressure guiding pipes shall be carried out by cold bending, using a dedicated pipe bender, and the bending must be completed in one go. After bending, the tube should be free of cracks and dents. Special pipe cutting knives should be used to cut pipes, and the cut ends should be smooth without burrs. 1.1.124 The slope for laying the pressure conduit of pressure instruments is generally 1:10 to 1:30; in special cases, it can reach 1:50. Its inclination should ensure the removal of gas or condensed liquid. 1.1.125 The length of the pressure guiding pipe between the throttling device and the differential pressure transmitter or flow meter should be no less than 3 m at the minimum, and no more than 30 m at the maximum. Its slope is generally 1:10 to 1:20, and in special cases it can be reduced to 1:50. 1.1.126 The pipeline between the pressure tapping point and the instrument or transmitter should be as short as possible; for low-pressure or micro-pressure media, it shall not exceed 30 m in length, and for other pressure media it shall not exceed 50 m. However, the pipeline leading to the transmitter must be at least 3 m long. 1.1.127 When connecting instrument pipelines to instruments, the instruments should not be subjected to mechanical pressure. The primary valve of the pressure guiding pipeline is installed after the sampling element, as close to it as possible, while the secondary valve is placed before the measuring instrument in a location that facilitates operation. 1.1.128 The pressure guiding pipelines shall be press-tested simultaneously with the process pipelines and process equipment. 7. Degreasing of instrument pipelines 1.1.129: Select an appropriate degreasing solvent in accordance with the requirements of design or construction specifications. Degreasing agents can be used in combination, but they must not come into contact with strong acids or strong bases. 1.1.130 Degreasing operations should be carried out in a well-ventilated area. Personnel responsible for degreasing must wear the necessary protective gear, masks, rubber gloves, protective clothing, goggles, and long boots. If the degreasing agent comes into contact with the mouth or eyes, it should be immediately rinsed with water. 1.1.131 For oxygen pressure measurement pipelines, the valves, pipes, fittings, etc. installed must be degreased in accordance with the oxygen installation procedures; they can be put into formal use only after passing the inspection. 1.1.132 For instrument tubes supplied individually, they can be soaked in a degreasing tank, or a stainless steel tube with a diameter of Dn100 and a length of around 6 meters can be used: one end of this tube is sealed off while the other end is raised; an appropriate degreasing agent is then poured in, and the instrument tube is placed inside this Dn100 tube for soaking for 1 to 1.5 hours. For instrument pipelines supplied in disc form, the circulation pump injection method is used: one end of the pipe is connected to the pump’s outlet, and the circulation pump is started until satisfactory results are achieved. To degrease the instrument components, they should be immersed in a degreasing agent for 2 hours. 1.1.133 Inspection method: Wipe the surface of the degreased parts with clean, dry white filter paper; there should be no oil stains on the paper, and this must be approved by the owner’s on-site representative. 1.1.134 Protection of instruments and pipelines after degreasing: After degreasing, the instruments and associated pipelines should be dried using natural ventilation, or with clean, oil-free, dry air or nitrogen; both ends should be sealed with packing tape and labeled. It is strictly prohibited for them to become contaminated by oils during installation. Degreasing agents should be stored properly. 1.1.135, Degreasing inspection. Wipe the surface of the degreased parts with clean, dry white filter paper; if no oil stains remain on the paper, it is considered that the degreasing process was successful. 1.1.136 After degreasing, when conducting pressure tests and instrument calibration tests on instruments and instrument piping, grease-free media must be used. 8. Testing of instrument tubes 1.1.137: Before pressure testing, it shall be checked that there are no cases of missed welding, blockages, or incorrect connections in the pipelines. The accuracy of the test pressure gauge should be no less than grade 1.5, and its maximum display value should be 1.5 to 2.0 times the test pressure. 1.1.138 The pressure test of instrument pipelines shall use liquid as the testing medium. For instrument air supply pipelines, pneumatic signal pipelines, and instrument pipelines with a design pressure of not more than 0.6 MPa, gas can be used as the testing medium. 1.1.139 The hydraulic test pressure shall be 1.5 times the design pressure. Once this test pressure is reached, it should be maintained for 10 minutes; thereafter, the pressure is reduced to the design level, and the system is held at this pressure for another 10 minutes. The test is considered successful if the pressure remains constant and there are no leaks. Clean water should be used as the test medium. When the ambient temperature is below 5°C, anti-freezing measures should be taken. 1.1.140 The pressure for the pneumatic test shall be 1.15 times the design pressure. During the test, the pressure should be increased gradually and slowly; once the test pressure is reached, it should be maintained for 10 minutes, after which the pressure is reduced to the design level, and the system should remain at this pressure for 5 minutes. It is considered qualified if no leakage is detected using a foaming agent. Air or nitrogen should be used as the test medium. 1.1.141 When the process requires vacuum or leak testing, the associated instrument pipelines shall be tested together with the process pipelines. 1.1.142 After the pressure test is completed, it is advisable to relieve pressure at the other end of the pipeline. The liquid should be drained after the test. Electrical wiring 9. Fabrication and installation of steel supports 1.1.143: When fabricating the supports, careful calculations must be carried out based on the specifications and dimensions indicated in the drawings, to avoid using materials that are either too large or too small for the task. The fabrication of the bracket should be carried out by cutting materials according to the drawings, with no arbitrary changes allowed. When manufacturing the bracket, the material should be straightened out; there should be no curling or burrs at the cut edges of the material. Stress must be taken into account during welding. 1.1.144 The support frames installed along the process pipe racks and steel structures shall be fixed by welding, but they cannot be welded directly to the process pipes and equipment. When installing brackets along the process piping, they can be fixed using clamps ； When installing brackets along the process equipment, they can be welded to the outer frame of the process equipment ； The pipe clamps installed on the paper machine frame should be secured using threading. 1.1.145 The support frames installed along the outer wall surfaces and concrete structures shall be fixed using expansion bolts. When the support brackets and suspension arms of cable trays are fixed to concrete structures, no fewer than four expansion bolts shall be used. 1.1.146 The installed brackets should be secure, straight and level, of accurate dimensions, with even spacing, and present a neat and tidy appearance. Rust removal, as well as primary and secondary anti-corrosion painting, should be carried out before and after the installation of the bracket. 1.1.147: For the spacing between supports for directly laid cables, it should not be greater than 0.8 m when laid horizontally, and should not be greater than 1.0 m when laid vertically. 10. Cable tray installation 1.1.148: Before installing the cable trays, it is necessary to check whether they meet the requirements of the design and relevant specifications. The installation of the cable tray should follow the routes and positions specified in the design drawings; it is necessary to avoid process equipment and pipelines based on the actual conditions on site, and make full use of process pipe racks as well as earth-based structures for construction. 1.1.149 The cable trays should be installed horizontally and vertically, in an orderly manner. The cable tray is connected to the connecting plates using special semi-round head bolts, with the nuts located on the outside of the cable tray. Cables led out from the cable tray should have holes made using mechanical methods. The joints of cable trays and covers should be tightly fitted, and the ends of the trays should preferably be sealed. 1.1.150 Cutting of cable trays must be carried out using profile cutters, reciprocating saws, or hand saws; electric welding or gas welding shall not be used to cut or weld the trays during construction, in order to avoid damaging the protective layer. The cable tray is laid on the finished support arm and secured with bolts. 1.1.151 The cable tray shall maintain electrical continuity, with wires used for bridging at the connections. The cable tray is grounded using a dedicated grounding wire, which is led to the control room to connect with the main electrical protection grounding conductor. 1.1.152: The openings in the walls through which the cable trays in the control room pass should be sealed with fireproof boards and fireproof sealing compound after the cable trays have been installed and the cables laid. 1.1.153: The spacing between bridge rack supports should not exceed 2 meters on straight sections (except for bridge racks with large spans). The installation height, levelness, verticality, and turning radius of cable bridge racks must meet the requirements specified in the design documents and relevant standards. 11. Installation of cable protection pipes 1.1.154: After the cables are led out from the cable tray, they are protected using galvanized steel pipes, which are connected together by threading. The processing of galvanized steel pipes involves using threaders and cutters for cutting and threading, as well as pipe benders for bending; electrical welding or cutting is not permitted. After fabrication, the protective tube should have no cracks on its outer surface, a smooth inner surface free of burrs, a bending deformation not exceeding 10% of the tube’s outer diameter, and no dents or cracks. The bending radius is selected based on the cable cross-sectional type, and should not be less than the minimum bending radius of the cable being used. The pipe ends should be smooth without burrs, and the thread length for connecting pipe fittings should be 4 to 5 threads. There should not be more than two straight bends per single protective tube. 1.1.155 When the protective tubes are installed openly on the supports, they should be arranged neatly and aesthetically, and fixed firmly using tube clamps along the supports. When the pipeline is long (with straight sections exceeding 30 meters), at bends and branch points, or when the total angle of bends exceeds 270°, or in areas where it is not possible to bend the pipe directly, aluminum alloy wire ducts and fittings should be used as connectors for piping, and lock nuts should be used to secure the protective tubes firmly. The wire conduit should be sealed with sealant. 1.1.156 The protection pipe should be laid along the shortest possible path; welding should be used for the sleeves, and the ends of the pipes must be concentric and located at the center of the sleeves. The welding must be secure, the welds must be tight, and anti-corrosion treatment must be applied (the outer wall of steel pipes buried in concrete does not require anti-corrosion treatment). 1.1.157 When the buried protective pipe is brought out of the ground, its opening should be at a height of 200 mm above the ground surface. When entering a floor-standing tray cabinet, the pipe outlet should be 50 mm above the ground level. 1.1.158 The connection between the protective tube and the instrument equipment as well as the junction box shall be sealed using metal flexible tubes or sealed joints, and waterproof bends shall be provided. The piping shall be arranged neatly and aesthetically, and guards shall be installed at the pipe ends to protect the cables. The protective tube shall be grounded and maintain electrical continuity. 12. Optimal laying of cables 1.1.159: Cables should be laid in accordance with the construction drawings. The method of cable laying should be optimized, with the aim of saving cable materials and complying with relevant standards as well as the actual conditions of on-site installation, so as to avoid or minimize unnecessary waste and losses. 1.1.160 Upon the arrival of the cables, each coil of cable should be numbered, and its length recorded in order to prepare a statistics table for the incoming cables. Before laying the cables, it is necessary to calculate the actual length of each cable based on the actual conditions on site. Then, based on the total length of each coil of cables, determine the coil number to which each cable belongs, and note this down in the cable arrival record sheet. When laying the cables, it is essential to follow the designated numbering system strictly, without making any arbitrary changes. 1.1.161 When laying the cables from the same cable reel, they should be laid in order from longest to shortest to avoid intermediate cable joints. Cable laying should be carried out after the panels and cabinets are in place and the exact locations of the on-site instrumentation are determined, to avoid unnecessary cable laying. Sufficient length should be reserved at both ends of each cable after it is laid (1.5 m at the site instruments and junction box end, and a length equal to the height and width of the cable tray at the control room end), but this amount must be determined carefully; no arbitrary increase is allowed. 1.1.162 The bending radius of the cable should not be less than 10 times its outer diameter. 1.1.163 Before installation, an electrical continuity check (conductivity test) should be conducted on the entire cable. The insulation resistance should be measured using a 500V megohmmeter (for circuits with a voltage of less than 100V, a 250V megohmmeter is used); this value should not be less than 5 megohms. This check helps to identify any issues or potential problems with the cable, and installation should only proceed after such checks have been completed. 1.1.164 When laying cables, care should be taken to prevent the cables from twisting, rubbing against the ground, or being dragged over sharp edges, so as to avoid damaging them ； Cables should be laid together along the shortest path, in a straight and orderly manner for an aesthetically pleasing appearance, with proper spacing to avoid intersections. 1.1.165 Cable laying should also avoid process equipment and pipelines, in accordance with the principle of not interfering with operations, maintenance, and traffic. Cables should not be installed in areas prone to mechanical damage, where corrosive substances are released, in humid conditions, or in environments subject to strong magnetic or electrostatic fields; otherwise, protective or shielding measures should be taken. 1.1.166 The wiring should not be laid above high-temperature equipment or pipes, nor below equipment or pipes containing corrosive liquids. Insulation measures should be taken when the ambient temperature around the line exceeds 65°C. When there is a fire source near the wiring, high-temperature cables should be used and fire prevention measures taken. 1.1.167 The cables for this project can be laid either along cable trays or through conduits. When the cables are laid on cable trays, they should be secured with straps every 1500 mm in the horizontal sections, and every 700 mm in the vertical sections. The cable should be laid naturally and not too tightly. 1.1.168 The transmission signal of the instrument is a weak signal; when it is routed along cable trays, it should be kept away from electrical power cables to avoid interference. The instrument power cable should be routed separately from the signal cable. Cables with different signals and voltage levels should be arranged separately, and metal partitions should be used to separate the AC power cables from the instrument signal cables within the same tray. Cables of different circuits, different voltage levels, as well as AC and DC cables, shall not be placed in the same conduit. Joints and kinks inside the tube are not allowed, with appropriate margin. After the cable is inserted into the steel pipe, the end of the pipe must be sealed. 1.1.169 When instrument cables intersect with power cables, the intersection should preferably be at a right angle. When laid in parallel, the clear distance between them shall meet the design requirements and shall not be less than 0.5 m. 1.1.170 The cables running from the field instruments to the cable tray or junction box, and from the junction box to the cable tray, shall be protected by pipes, and connected using hoses or sealed connectors. Before laying the cable in conduits, any debris and moisture inside the wire protection conduit must be removed. 1.1.171 Instrument signal circuits, safety interlock circuits, instrument power supply circuits, compensation wires, and intrinsically safe instrument circuits shall each use their own protective tubes. 1.1.172 After the cables are laid, it is necessary to check their conductivity and measure their insulation resistance to ensure they meet the specified standards; each cable must be equipped with the designated cable label at both ends. 1.1.173 When outdoor cables enter indoor areas, waterproofing and sealing measures should be in place. The bottoms of the instrument panels, boxes, and cabinets should also be sealed after the cable installation is completed. 13. Fabrication and installation of cable terminations 1.1.174: The fabrication of cable terminations should minimize the time during which the insulation is exposed, and it should be carried out under favorable weather conditions. If wiring cannot be carried out immediately after the cables are laid, the cable ends exposed at the site should be properly insulated to prevent any impact on their insulation properties. 1.1.175 Both control cables and power cables are manufactured in accordance with the standards for low-voltage, dry-type cable terminations. When manufacturing shielded cable terminals, the insulation should not be damaged when the shield grounding wire is pulled out. When stripping the cable, do not damage the cable core or the remaining insulation layer. 1.1.176 Cable terminations must be securely fixed, and the wiring must be verified. In the control room, all cable terminations on the same panel should be firmly fixed at the same height, and signage should be installed. Appropriate margin should be left at the wiring positions on the terminal board; the wires should be of uniform length and arranged neatly, with terminal numbers clearly visible. The wire connections should be securely fastened using copper terminals. 1.1.177 The spare conductors of the control cable shall be reserved for the maximum length that may be used, and connected to the spare terminals on the terminal board. 1.1.178 When measuring the insulation resistance of cable lines, it is necessary to disconnect the connected measuring equipment and the lines. 14. Explosion Protection and Grounding 14.1 Explosion Protection 1.1.179: This device is located in areas prone to fire, dust, and explosion hazards. Instruments, electrical equipment, and materials installed in such areas must meet the design requirements and be equipped with nameplates and explosion protection markings. 1.1.180 In instrument boxes, wire conduit boxes, and when introducing cables for explosion-proof instrument equipment installed in areas at risk of explosion and fire, explosion-proof sealing rings or sealing fillers should be used for tight sealing, and any excess holes on the enclosure must be sealed in an explosion-proof manner. 1.1.181 At the entrance to the control room cable tray, after the cables have been laid, seal it using sealing putty and quick-setting sealing compounds. When cable trays or cable ducts pass through explosion-hazardous areas of different grades, the partition walls must be filled and sealed. When the protective tube passes through explosion-hazardous areas of different categories, the partition walls must be separated using explosion-proof sealing components, with proper filling and sealing in place. 1.1.182 For the installation of instruments with explosion-proof sealing using packing, the sealing material must be filled appropriately to ensure that there are no gaps between the cable and the sealing joint, thereby preventing flammable and explosive gases from reaching the instrument junction box or wiring box, and achieving isolation of the gases inside the conduit from those inside the instrument junction box or wiring box. 1.1.183 The explosion-proof junction boxes (cabinets) for cables on-site, as well as the conduit passing boxes, must be sealed. The conduit shall be connected to the junction boxes, distribution cabinets, and passing boxes using cylindrical pipe threads, with an effective engagement length of more than 5 thread pitches. Conductive anti-rust grease shall be applied to the threads to maintain good electrical continuity. Wrapping with hemp, applying lead, using insulating tape, or other types of paint is prohibited ； For unused interfaces, seal them with plugs. Between the sealed fittings and instruments, sensing elements, and electrical equipment, explosion-proof flexible hoses can be used for connection. 1.1.184 The ventilation ducts of explosion-proof instrument boxes equipped with positive pressure ventilation must remain unobstructed, and it should be difficult to install shut-off valves; the pressure inside the box must be maintained at a level not lower than that specified in the design. 1.1.185 When intrinsically safe circuits and non-intrinsically safe circuits are laid in the same cable tray, they shall be separated by a grounded metal partition. The grounding wires and shielding connections in intrinsically safe circuits shall have an insulating layer or be wrapped with insulating tape. The grounding wire shall be a copper-core insulated wire or cable, with yellow and green markings on the insulation layer. 1.1.186 The safety barrier shall be installed on one side of a safe area and reliably grounded. Different types of safety barriers cannot be used interchangeably. The shield of shielded cables and wires should not be connected to the ground terminal of the safety barrier. 1.1.187 The on-site wiring for explosion protection and fire prevention must be firm and reliable, with good contact. 14.2 Grounding 1.1.188: Grounding is divided into safety protection grounding and signal grounding, each with its own separate grounding electrode. The installation of the protective grounding electrode is carried out by the electrical engineering team. The cross-sectional area of the grounding wire shall comply with the specifications of the design and the manufacturer. The grounding wire is made of multi-strand copper wires in yellow and green colors, and the ground resistance must meet the design specifications. 1.1.189 The enclosures of instrumentation equipment, cable trays, protective pipelines, etc., shall all be provided with protective grounding; however, for local instruments whose supply voltage is not higher than 36V, protective grounding may be omitted if there are no special requirements. Protective grounding can be connected to the electrical grounding grid through a grounding conductor main, or directly to the electrical grounding grid itself. The connection should be reliable, but grounding in series is not allowed; all grounding branches should be connected to the grounding busbar. The grounding resistance of the protective ground shall meet the design specifications. 1.1.190 The grounding of the signal circuit is connected to a separate grounding electrode through a grounding trunk, forming an independent grounding system. The method and material for the separate grounding electrode shall comply with the design requirements. The grounding for the signal circuits of the instrumentation and control systems, as well as the shielding grounding, should share the same grounding device. Each circuit must be grounded at a single point, and the spare conductors of the shielding wires and cables should be grounded on the control room side. 1.1.191 The shielding ground wire of shielded cables must be reliably grounded, and each cable may have only one grounding point, which is generally connected to the grounding bus in the control room. The spare conductors in multi-core cables should also be grounded at one point ； The spare core wire of the shielded cable should be grounded on the same side as the cable’s shielding layer. To prevent the shielding grounding wire inside the junction box from coming into contact with the box itself, resulting in multiple grounding points, a plastic tube or paraffin tube should be placed around the grounding wire. 1.1.192 The shielding layer at the site must not protrude outside the protective layer, and the shielding layers of the same circuit shall have reliable electrical continuity. 1.1.193 The grounding point of the instrument signal circuit is on the secondary instrument side. The protective grounding resistance value of the instrument system is 4Ω. 15. Individual calibration of instruments 15.1 General provisions for individual calibration of instruments 1.1.194 The conditions, items, and methods for instrument calibration and testing shall comply with the provisions in the product’s technical documents as well as the design requirements. If the manufacturer has provided specialized tools and testing equipment, those should be given priority. 1.1.195 Instrument calibration and testing should be carried out indoors, in a clean environment free from vibrations and electromagnetic interference. The indoor temperature should be maintained between 10 and 35°C. 1.1.196: Only professional personnel trained in instrument calibration shall carry out the individual calibration of instruments. Moreover, before starting the calibration process, it is necessary to be well familiar with the instrument’s performance, technical specifications, process requirements, and relevant instructions. 1.1.197 The individual debugging of instruments is carried out by two persons, in strict accordance with the instrument debugging procedures. Standard instruments used for debugging must be within their calibration period and have an accuracy level two grades higher than that of the instrument being calibrated (or an absolute value of basic error that is less than 1/3 of the absolute value of the basic error of the instrument being calibrated). Before calibration, it is necessary to carefully verify the instrument’s tag number, specification model, characteristics, dimensions, material, measurement range, scale, division value, and unit of measurement in accordance with the instrument specification sheet (equipment list). 1.1.198 All instruments shall undergo a visual inspection, and electric instruments powered by 220VAC shall be tested for insulation resistance. 1.1.199: There should generally be no fewer than 5 calibration points for instruments, which should be selected evenly across the scale range. When increasing or decreasing the signal during adjustment, it should be done in a uniform manner in one direction, with even verification throughout both the forward and reverse movements. When adjusting in the reverse direction, the signal value should first be increased to slightly exceed 5% of the maximum range value before proceeding. During loop testing, there should generally be no fewer than 3 calibration points for the instruments. 1.1.200, Zero adjustment: When the instrument’s indication error shows a one-way, constant-amplitude deviation, the zero point can be adjusted; the adjustment range is 3% to 5%. 1.1.201, Range adjustment: When the indication error of the instrument shows an excessive increase or decrease in one direction, the potentiometer can be adjusted. After debugging, a certain margin should be left, and the zero point should be checked; if it is incorrect, adjustments should be made repeatedly. 1.1.202, Variance adjustment: The main causes of variance are a large dead zone in the amplifying elements, low sensitivity, excessive gaps in the mechanical transmission, or mechanical friction; it is necessary to adjust the sensitivity appropriately or modify the mechanical components. 1.1.203 The critical components inside the instrument must not be removed arbitrarily; if removal is necessary due to some issue, it can only be done after obtaining permission from the construction supervisor and the technical personnel of Party A, in order to carry out inspection or replacement. When welding is required, an appropriate soldering iron should be selected; the soldering iron must be properly grounded to eliminate static electricity. After welding, a thorough inspection should be carried out to ensure that there are no cases of weak soldering or incomplete soldering. 1.1.204 After the calibration of instruments is completed, it is necessary to fill out the calibration records carefully. These records should be clear and neat, and kept properly so that a certification document can be issued to the owner. For instruments installed on-site that already have access to power and gas supply, power and gas should be supplied regularly to maintain them. 15.2 Items and methods for single instrument calibration 1.1.205: Calibration and testing of pointer-type display instruments. The instrument panel should be clean, and the scales and markings should be clear. The pointer should move smoothly and flexibly across the full scale, and its indication error and return error must meet the requirements specified for the accuracy of the instrument. Check the accuracy, range, basic error, and zero point of the bimetallic thermometer. Check the gauge’s accuracy, range, basic error, and zero adjustment on a pressure calibration bench ； Diaphragm pressure gauges use a compensated micropressure gauge as the standard instrument. The reading of digital display instruments should be clear and stable, and the reading error within the measurement range shall comply with the accuracy specifications of the instrument. 1.1.206 For pointer-type recording instruments, the indication error and return error of the pointer over the entire scale range shall meet the requirements specified for the accuracy of the instrument. The markings or print dots on the recording device should be clear, and the paper should move properly. The numbers or colors printed on the record paper should match the identifiers marked on the switch and terminal blocks. 1.1.207: Thermal resistor (thermocouple): Check for continuity and record the resistance value at room temperature. 1.1.208 The accuracy of the accumulation meter shall meet the requirements specified in the product’s technical specifications. For flow measurement instruments, the manufacturer’s product certificate and calibration proof must be verified. 1.1.209 The calibration of electromagnetic flowmeters is carried out on-site after installation, using the specialized calibration instruments provided with the device to adjust the zero point and range. To zero a flow meter, first drain the gas from the flow sensor, fill it with the fluid to be measured, and then close the valves upstream and downstream of the sensor. Zeroing is carried out at a temperature close to the operating temperature; if the temperature changes significantly, zeroing must be repeated. At the converter, an analog input signal is applied using a standard comprehensive calibration instrument, and the output is checked and adjusted accordingly. 1.1.210: To check a rotameter, the rotor is manually pushed up or down; the direction of change in its indication should be consistent with the direction of rotor movement, and a signal of 4–20mA is generated. 1.1.211 Transmitters and converters shall undergo input and output characteristic tests and calibration; their accuracy shall meet the requirements specified in the product’s technical specifications. The ranges and types of input and output signals shall be consistent with those indicated on the nameplate and specified in the design documents, and they shall be compatible with the display instruments. Pressure and differential pressure transmitters should also undergo zero-point and range adjustment, as well as zero-point shift adjustment. 1.1.212, Intelligent pressure transmitters and other transmitters: Zero and range setting. It is very convenient to set and adjust the range and zero point of intelligent transmitters; since there are no moving (or adjustable) mechanical mechanisms or potentiometers, and their accuracy is extremely high, no accuracy calibration is required. The software configuration of intelligent pressure transmitters is usually carried out using a HART protocol-based handheld programmer, while for other transmitters, the setting and modification of their various parameters are generally done on the built-in intelligent, integrated multi-functional display. 1.1.213 The tests and calibrations for evaluating the detection, sensing, conversion, and other performance characteristics of analytical instruments, including the requirements for standard samples used in these tests, shall all comply with the provisions of the product’s technical documentation as well as the design requirements. 1.1.214 The display of control instruments, control point errors, proportional, integral, and derivative actions, signal processing as well as various control and operational performances shall all be inspected, tested, calibrated, and adjusted in accordance with the provisions of the product’s technical documents and design requirements. 1.1.215、Check the opening degree of the control valve (regulating valve) at 0～50～100% ； Check of the valve position (limit) switch. Valve body pressure test and seat sealing test. When testing pneumatic control valves, clean plant instrument air should be used as the air source if available; bottled compressed nitrogen can also be used as an alternative air source. To prevent blockage or corrosion in the air circuit of the control valve actuator, it is necessary to avoid using untreated air from air compressors. The calibration of control valves also includes valve positioners, filter pressure reducers, solenoid valves, proximity switches, etc.; the calibration is carried out as part of a complete test with the valve. During testing, the actuator should be adjusted to the operating condition specified in the design. The accident isolation valve shall also be tested for the full stroke time. 1.1.216 Check of ON/OFF (shut-off) valve solenoid and OPEN/CLOSE positions ； Check of the valve limit switch. The control solenoid valve that comes as part of the on/off valve set should be checked using a megohmmeter to determine whether its insulation is in good condition. It is also necessary to verify that the air circuit meets the required standards and that there are no leaks. Additionally, the input electrical signals, the operation of the switch contacts, and the switching time should be checked, with all findings recorded. 1.1.217 Flammable gas alarm: The complete set includes a sensor, a control and display card, a calibration device, a common card, a common-power alarm device, and a chassis. A calibration device is used to conduct routine inspections and verifications of the alarm, including the setting of alarm values, display functions, zero point, accuracy, range, etc.; in addition, the wiring of the entire system is checked and its functionality is tested. 1.1.218, Tuning fork level switch: During inspection, place the tuning fork prongs upward; after powering it on, press the end of the tuning fork with your finger to force it to stop vibrating, and the output relay should activate. 1.1.219: After passing the verification, the instruments are protected from vibration; the individual testing of these instruments meets the technical requirements, and the users are satisfied. Once the inspection is complete, the verification data is entered in a dedicated form for future reference, and the original records are properly preserved. The accessories and instruction materials for each instrument should also be properly stored for handover. 16. Instrumentation system circuit debugging 16.1 Preparation for circuit debugging 1.1.220 Before putting the DCS system into operation, circuit tests of the system should be carried out first. The test should use official power and gas supplies. 1.1.221 The instrument equipment, devices, instrument lines, and instrument pipelines in the circuit have been installed. 1.1.222 The common functions of each instrument in the system (such as indication, alarm, adjustment, accumulation, counting, manual switching, etc.) have been tested. 1.1.223 The input and output circuits from the field to the terminal cabinets in the control room have passed the testing. 1.1.224. According to the design drawings, carefully recheck and confirm that key parameters in the instrument system, such as the installation of instrument equipment, piping, wiring, air supply, power supply, as well as the tag numbers, measurement ranges, interlock alarm values displayed on the DCS operation station, the air supply pressure for control valves, and the range of transmitters (including offset), all correspond to the parameters specified in the instrument specifications and on the instrument nameplates. 16.2 Test of the detection circuit 1.1.225: An analog standard signal is applied at the signal input terminal of the detection circuit; the reading error of the display instruments in this circuit shall not exceed the square root of the sum of the squared allowable basic errors of each individual instrument in the circuit. 1.1.226. For the temperature detection circuit, an analog signal with an input resistance value or mV value is generated at the output of the sensing element. 16.3 Tests of control circuits 1.1.227: The operating direction of the controller and actuator shall meet the design requirements. 1.1.228 Send control signals to the actuator through the output of the controller or operation station, and check whether the movement direction and position throughout the full range of the actuator’s actuating mechanism are correct; if the actuator is equipped with a positioner, it should also be tested simultaneously. 1.1.229 When the opening degree as well as the start and end signals of the actuator are displayed on the controller or operation station, inspections and tests should be carried out simultaneously. 16.4 Alarm system testing 1.1.230: The instrumentation or components in the alarm system shall be calibrated according to the design set values. 1.1.231: Input an analog signal at the signal generation end of the alarm circuit, and check whether the alarm lights, sound alerts, and screen display are functioning correctly. 1.1.232 The silencing, reset, and recording functions of alarms shall be proper. 1.1.233 The test is conducted at the AI, DI, AO, and DO points to check the configuration content and logical functions. The coverage rate for loop tests is 100%. 1.1.234 The coordination and commissioning of large-scale units or other complete sets of automatic control systems shall be carried out in accordance with the manufacturer’s personnel or the product instructions; this plan does not provide detailed descriptions on this matter.