Layout requirements for common equipment in chemical plants

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What are the different ways to arrange towers? What are the specific requirements? Arrangement of towers: 1. Single-row arrangement – this is the most common arrangement. When there are two or more towers or vertical containers on one side of the pipe gallery, their centerlines are usually aligned with each other. If two or more towers are equipped with a shared platform, it is advisable to align their centerlines or their tangents ； 2. For single-row arrangements, towers with a smaller diameter and higher height can be arranged in double rows or in a triangular pattern; in this way, platforms can be used to connect the towers together, thereby enhancing their stability. However, slidable guide nodes should be used for the platform’s root components to accommodate the effects of thermal expansion at different operating temperatures ； 3. It adopts a framed layout; for towers with a diameter of DN≤1000mm, they can also be placed within the frame or on one side of it. Improve its stability using a framework, and install platforms and ladders. For segmented towers installed on a framework, when motorized lifting equipment cannot be used, maintenance lifting facilities should be provided on the framework. What are the requirements for the layout of the tower and its associated equipment? Layout requirements for the tower and its associated equipment: The tower and its related equipment, such as feed heaters, reboilers that use non-flame heating, top condensers, reflux tanks, bottom extraction pumps, etc., should be arranged in sequence according to the process flow. If necessary, an independent operating system can be established within a specific area, which facilitates operation and management. How is the distance between towers and vertical pipe supports arranged along the pipe rack and the pipe rack itself determined? The distance between towers and vertical vessels arranged along the pipe rack and the pipe rack itself shall be determined in accordance with the following requirements: When pumps are to be installed between a tower and the pipe rack, this distance shall be determined based on the operational, maintenance, and piping requirements of the pumps ； When no pumps are installed between the tower and the pipe tray, the distance between the outer wall of the tower and the centerline of the pipe tray columns should not be less than 3 m. How is the distance between towers or between a tower and other adjacent equipment determined? The distance between towers or between towers and other adjacent equipment must not only meet the requirements for the layout and installation of pipes, platforms, instruments, and small equipment, but also satisfy the needs related to operation, maintenance access, and foundation layout. The clear distance between the two towers should not be less than 2.5 m. What requirements should be met regarding the installation height of towers and vertical containers? (1) When using internal pressure or the gravity of flowing fluid to convey materials to other equipment or pipelines, it shall be determined by their internal pressure as well as the pressure and height at the destination equipment or pipelines ； (2) When pumping liquid, the installation height of the equipment should be determined by the pump’s net positive suction head and the pressure drop in the suction pipeline ； (3) For towers equipped with non-open-flame reboilers, the installation height shall be determined based on the required relationship between the tower and the reboiler as well as operational requirements ； (4) It shall meet the minimum clearance required for the installation and operation of the pipes at the bottom of the tower, and the foundation surface of the tower shall be at least 200 mm above the ground level. What are the general requirements for the layout of heat exchange equipment? (1) Shell-and-tube heat exchange equipment associated with the distillation tower, such as the reboiler at the bottom of the tower and the condenser at the top of the tower. The processes should be arranged in sequence near the distillation tower ； (2) For heat exchangers where heat is exchanged between two fluids, they should be located as close as possible to the pipes connecting the inlets and outlets of these two fluids ； (3) Shell-and-tube heat exchangers in which one fluid exchanges heat with several different fluids should be arranged in groups ； (4) Coolers for several different materials using water or a coolant should be arranged in groups ； (5) For heat exchange equipment arranged in groups, it is advisable to align the center lines of the support foundations. When the spacing between the supports is different, it is preferable to align the center lines of the support foundations at one end. To facilitate pipeline connection, the heat exchanger installed on the ground can also have its tube side inlet and outlet nozzles aligned along their centerlines ； (6) Heat exchange equipment should be installed on the ground as much as possible; however, when there is a large number of such devices, they can be installed on frames. l) When floating-head heat exchangers are installed on the ground, the following requirements must be met: there should be a space of at least 0.6 m on both sides of the floating head and the tube box, and there should also be a space of at least 1.2 m in front of the floating head end ； In front of the tube box, starting from the end of the tube box, there should be a space that is at least 1.5 m longer than the length of the tube bundle. 2) When a floating-head heat exchanger is installed on a frame, the following requirements must be met: the clear height of the platform in front of the floating-head end should not be less than 0.8 m; the clear height of the platform in front of the tube box end should not be less than 1 m. The platform shall be equipped with removable railings, and consideration shall be given to the space required for removing the tube bundle ； The height of the framework should be sufficient to accommodate the lifting of the tube box and the head cover of the float head of the heat exchanger. (7) To save space or facilitate operational procedures, two heat exchange units can be arranged one on top of the other. However, for two-phase flow media or heat exchangers with a shell diameter of 1.2 m or more, overlapping arrangements are not suitable ； (8) The minimum distance between heat exchangers, as well as between heat exchangers and other equipment, should not be less than 0.7 m ； (9) Heat exchange equipment for heavy oils or materials that pollute the environment should not be installed on the framework ； (10) Above heat exchangers whose operating temperature is above the auto-ignition point of the material, no other equipment should be installed if there is no floor or platform to separate them. What are the general requirements for the layout of a reboiler? (l) The distance between the reboiler heated by an open flame and the tower should be arranged in accordance with the requirements for the distance between heating furnaces and towers specified in the fire protection codes ； (2) Horizontal reboilers heated by steam or a heat carrier should be located near the tower, maintaining a certain height difference from it (determined by the process design); the distance between them must meet the requirements for pipeline layout, and one end of the reboiler’s tube bundle should provide space and access for maintenance ； (3) Vertical reboilers should be supported by a tower and installed on the side of the tower, maintaining a certain height difference from the tower (determined by the process design). There should be sufficient maintenance space above it ； (4) When a tower requires multiple vertical reboilers connected in parallel, the location and installation height of the reboilers must not only meet the process requirements but also satisfy the layout requirements for the inlet and outlet manifolds, as well as facilitate operation and maintenance. What are the general requirements for the layout of air coolers? (l) Air coolers (hereinafter referred to as air coolers) should be located on the leeward side of the direction of the wind with the lowest frequency throughout the year at the plant site ； (2) The air coolers should be located above the main corridor, on the top layer of the framework, or at the top of the tower ； (3) Air coolers should not be installed above equipment for which the operating temperature is equal to or higher than the auto-ignition point of the material, as well as above equipment used for transporting and storing liquefied hydrocarbons ； Otherwise, partitions made of non-combustible materials should be used for isolation and protection ； (4) When multiple groups of air coolers are arranged together, they should be arranged in the same pattern; a linear arrangement is recommended ； It should be avoided to have one part arranged in rows while another part is arranged in columns ； (5) For inclined-top air coolers, the ventilation surface should not be oriented toward the dominant summer wind direction. Slant-roof air coolers should be arranged in rows; when arranged in rows, there should be a space of no less than 3 meters between the rows ； (6) The distance between the frame columns of two humidified air coolers or combined dry-wet air coolers arranged side by side should not be less than 3 m ； (7) Platforms shall be provided at the tube boxes at both ends of the air cooler bundle and at the drive machinery ； (8) Sufficient maintenance space and access paths should be provided on the ground beside the frame or main corridor where the air cooler is installed. How is the layout of air coolers designed to avoid thermal air circulation within them or between them? (1) Air coolers of the same type are arranged at the same height ； (2) Adjacent air coolers are arranged close to each other ； (3) The grouped dry forced-air coolers and the induced-air coolers shall be arranged separately; the induced-air coolers should be located on the downwind side of the wind direction corresponding to the minimum frequency of wind occurrence throughout the year for the forced-air coolers ； (4) When air-cooled exchangers of the induced draft type and those of the forced draft type are arranged together, the tube bank of the forced draft type air-cooled exchanger should be raised. What are the general requirements for the layout of a heating furnace? (1) Open-flame heating furnaces should be located concentratedly at the edge of the facility, near fire exits, and on the downwind side of the wind direction with the lowest frequency of occurrence throughout the year for flammable gases, liquefied hydrocarbons, and Class A/B liquid equipment ； (2) The heating furnace and other open-flame equipment should be placed together ； (3) Several heating furnaces can be arranged in rows aligned along the center line of the furnaces. The clear distance between the two heating furnaces should not be less than 3 m ； (4) When using mobile maintenance equipment to lift the heater tubes, there must be passages for the mobile maintenance equipment to travel through, as well as maintenance areas. For heating furnaces with horizontal furnace tubes, on the side where the tubes are removed, the length of the maintenance area should not be less than the length of the furnace tubes plus 2 meters ； (5) The distance between the outer wall of the heating furnace and the edge of the maintenance road should not be less than 3 m ； (6) For heating furnaces equipped with steam generators, the steam drum should be located at the top of the furnace or on a framework adjacent to it ； (7) The distance between the heating furnace and its associated fuel gas separation tank and fuel gas heater should not be less than 6 m ； (8) When the heating furnace is equipped with auxiliary equipment such as air preheaters, blowers, and induced draft fans, the layout of such auxiliary equipment shall not hinder the maintenance of both the equipment itself and the heating furnace ； (9) The fire protection distance between heating furnaces and liquefied hydrocarbon equipment installed outdoors shall not be less than 22.5 m. When a solid wall made of non-combustible materials is erected between the equipment, this distance may be reduced, but shall not be less than 15 m. The height of the solid wall should not be less than 3 m, and it should be no more than 5 m away from the heating furnace; it must also prevent combustible gases from entering the furnace ； When the wall facing the heating furnace in the building housing the liquefied hydrocarbon equipment or the Class A gas compressor room is a closed wall, the distance between the heating furnace and the building can be reduced, but it must not be less than 15 m. What are the requirements for the layout of vertical containers? The shape of a vertical container is similar to that of a tower, except that its internal structure is less complex than that of a tower. The layout and installation height of vertical containers can follow the requirements applicable to towers; in addition, the following considerations should also be taken into account: (1) For ease of operation, vertical containers can be installed on the ground, floor slabs, or platforms, or they can pass through floor slabs or platforms and be supported on them using brackets ； (2) When a vertical container is installed through a floor or platform, efforts should be made to prevent the liquid level indicators and control instruments on the container from also passing through the floor or platform ； (3) In vertical containers, in order to prevent the solidification of viscous materials or the sedimentation of solid materials, and when there are high-capacity mixers inside, support structures should be installed as close to the ground as possible in order to avoid vibration effects ； (4) For vertical vessels with an open top, when manual charging is required, the height of the charging point should not exceed 1 m above the floor or platform. If it does exceed 1 m, it is necessary to provide a charging platform or steps. What are the requirements for the layout and installation height of horizontal containers? (l) Horizontal containers should be arranged in groups. Horizontally mounted vessels arranged in groups should be aligned according to the centerline of their support foundations or according to the tangents of their heads. The clear space between horizontal containers can be taken as 0.7 m. (2) When determining the dimensions of horizontal vessels in process design, it is advisable to use vessels of the same length but different diameters to facilitate equipment layout. (3) When determining the installation height of horizontal containers, in addition to meeting requirements such as the gravity flow of the material or the pump suction height, the following requirements must also be satisfied: if there is a liquid collection tank below the container, sufficient space must be provided for the operation and monitoring instruments of that tank ； When an operation passage is required below the container, the clearance between the piping at the bottom of the container and the ground should be no less than 2.2 m ； When horizontally oriented vessels of different diameters are arranged in groups on the ground or on the same floor or platform, the elevation of the centerline of the smaller-diameter vessels may be appropriately raised so that it matches the elevation of the top surface of the cylindrical body of the larger-diameter vessels, thereby facilitating the construction of a common platform. (4) When horizontal containers are installed in a pit, proper measures must be taken to deal with water accumulation in the pit as well as the buildup of toxic, flammable, and explosive substances. The dimensions of the pit should meet the requirements for the operation and maintenance of the container. In rainy areas, it is advisable to consider installing a canopy above the pit. (5) When setting up platforms for horizontal vessels, considerations must be given to operations such as manholes and level gauges. The elevation of the top platform should be 150 mm lower than the flange surface of the top nozzle. When the height of the upper interface of the level gauge from the ground or operating platform exceeds 3 meters, the level gauge shall be installed near a straight ladder. A combined platform can be provided for horizontally arranged containers that are placed together. What are the different ways to arrange pumps? There are three ways to arrange pumps: outdoor arrangement, semi-outdoor arrangement, and indoor arrangement. (1) Outdoor arrangement: Pumps in an outdoor arrangement are usually placed together beneath or along the sides of the pipe gallery, or they can also be located near the equipment that needs to be pumped. Its advantages are good ventilation, as well as ease of operation and maintenance ； (2) Semi-open layout: Pumps arranged in a semi-open layout are suitable for rainy regions. Generally, pumps are placed beneath pipe racks, with canopies installed above the pipes. Alternatively, the pump can be placed on the lower floor of the framework, using the framework platform as a canopy. These pumps can be arranged in a single row, double row, or multiple rows, depending on the design requirements related to the pump ； (3) In indoor installations in cold or windy/sand-prone areas, the pump can be placed indoors. If the process requirements dictate that the equipment be installed indoors, then the pumps associated with it should also be installed indoors. What are the specific requirements for pump layout? The specific requirements for the arrangement of pumps are as follows: (1) Pumps arranged in rows should be grouped according to fire protection requirements, operating conditions, and material properties ； When the pump is installed in an open or semi-open area ； Pumps for flammable liquids whose operating temperature is equal to or above their autoignition point should be installed in a centralized manner ； There should be a fire separation distance of not less than 4.5 m between such pumps and combustible liquids whose operating temperature is below their auto-ignition point ； There should be a fire separation distance of not less than 7.5 m from liquid hydrocarbon pumps ； (2) When pumps are arranged in rows, it is advisable to place the pump outlets at one end. Align the population centerline, or align the pump end foundation edge line ； (3) When pumps are arranged in two rows, it is advisable to position the power ends of the two rows facing each other, leaving a maintenance passage in between ； (4) When the pump is located below or outside the main corridor, the minimum clear width of the passage in the pump area shall be 2 m, and the minimum clear height shall be 3 m. The width of the operation passage in front of the pump shall not be less than 1 m ； (5) When the pumps are installed below or outside the pipe gallery, whether in a single row or double row, the centerlines of the pumps and drivers should be perpendicular to the direction of the pipe gallery ； (6) When pumps are installed indoors, the clear distance between two rows of pumps should not be less than 2 m. The clear distance between the pump end or the side of the pump and the wall should meet the requirements for operation and maintenance, and should not be less than 1 m ； (7) Except for small pumps installed on a common foundation, the clear distance between the two pumps should not be less than 0.7 m ； (8) The base surface of the pump should be 200 mm above the ground level. The minimum value must not be less than 100 mm ； When installing a filter in front of the pump inlet, the height of the pump foundation should take into account the ease of cleaning and removing the filter ； (9) When vertical pumps are installed below the main corridor or beneath the framework, space should be left above them for the installation and maintenance of the pumps ； (10) Transport of highly hazardous substances (such as propylene?) Pump rooms for substances such as hydrocyanic acid should be separated from other pump rooms ； (11) The fire pump room shall be equipped with dual power sources ； (12) The utility standby pump should be located in the middle of the corresponding pump ； (13) The layout of the pump should take into account the requirements for flexible pipeline design. What are the general requirements for the layout of compressors? (1) The layout of the compressor unit and its auxiliary equipment shall meet the requirements of the manufacturer ； (2) The compressor should be located near the equipment to be pumped, and its auxiliary equipment should be placed close to the unit ； (3) The layout of combustible gas compressors shall meet the following requirements: The distance from open-flame equipment and non-explosion-proof electrical equipment shall comply with the provisions of the current standards **\"Code for Design of Electrical Installations in Explosive and Flammable Environments\" GB 50028 and \"Code for Fire Protection Design of Petrochemical Enterprises\" GB 50160 ； It is suitable for outdoor or semi-open placement. In cold or windy/dusty areas, it can be installed inside a factory building ； Gas compressor plants of Class A with a single-unit drive power of 150 kW or more should not share the same building with other rooms of Classes A, B, or C ； Above the compressor, no equipment containing Class A, B, or C liquids shall be installed, except for high-mounted lubricating oil tanks for internal use, which are exempt from this restriction. (4) For compressors arranged in a single layer, when the foundation is at a high level, an operating platform should be provided as needed ； When there are many auxiliary devices, it is advisable to arrange them in two layers. What requirements should the installation height of the compressor meet? The installation height of the compressor should be determined based on its structural characteristics. The installation height of the compressor, with its inlets and outlets at the bottom, shall meet the following requirements: (l) Requirements regarding the clearance between the inlet and outlet pipes and the ground surface ； (2) Requirements for the connection height between the import/export connection pipes and the pipes in the pipe gallery ； (3) Requirements for the installation height and dimensions of the filter on the intake pipeline ； (4) To reduce vibration, the installation height of the reciprocating compressor should be lowered. What fire safety regulations must be followed regarding the layout of the control room, power distribution room, and laboratory in the facility? (1) The control room and the power distribution room should be located on the ground floor of the building; however, if production requirements or other constraints exist, they can be placed on the second floor or higher ； (2) In installations where flammable gases that are heavier than air may be released, the indoor floors of control rooms, power distribution rooms, and laboratories should be at least 0.6 m above the outdoor ground level ； (3) The exterior wall of the control room facing the equipment side with fire hazards shall be a solid wall made of non-combustible material, without doors, windows, or openings ； (4) In the control room or laboratory, primary online analytical instruments for combustible gases, liquefied hydrocarbons, or combustible liquids shall not be installed. When the aforementioned instruments are installed in rooms adjacent to the control room and laboratory, the partition wall between them should be a fire wall. What requirements should the channel layout of production facilities meet? What are the minimum width and minimum clear height of the passages within the device? When arranging the equipment, necessary passages and areas should be considered comprehensively based on the requirements for construction, maintenance, operation, and fire safety. Inside the facility, application roads divide it into equipment and building areas with a floor area not exceeding 10,000 m2. When the floor area of the esterification polymerization, spinning, and post-processing facilities for synthetic fiber production exceeds 10,000 m2, passageways should be provided on both sides of them. The main traffic passage within the facility should be connected to the factory roads. (l) The installation of fire access routes shall meet the following requirements: When the width of the installation exceeds 60 m, a continuous fire access route shall be provided within the installation ； If the width of the facility is 60m or less and there are fire access routes on both sides of the facility, a continuous fire access route may not be required. Non-through roads within the facility should be provided with turnaround areas. The width of the road should not be less than 4m; the clear distance between the pipe rack on the road shoulder and the edge of the road surface should not be less than 1m. The inner turning radius of the road surface should not be less than 7m, and the clear height above the road surface should not be less than 4.5m. (2) The maintenance access road shall meet the requirements of the machinery used for mechanical maintenance regarding road width, turning radius, and load capacity, and shall lead to the lifting holes for equipment maintenance. (3) The main vehicle passages, fire escape routes, and maintenance passages within the facility should be arranged together. (4) The operation passages should be determined based on the frequency of production operations, routine inspections, minor repairs, etc., as well as the distribution of the operation points. What considerations should be taken into account when designing the piping layout along the tower? (1) It shall meet the requirements of the process piping and instrumentation diagram ； (2) The pipeline layout should be planned from the top to the bottom of the tower, starting with the location of the pipes at the top of the tower and those of large-diameter pipes, as well as the direction of gravity-fed pipes. After that, pressure pipes and ordinary pipes should be arranged, and finally, the pipes at the bottom of the tower and those of small diameter should be considered ； (3) Consideration should be given to ease of operation, maintenance, safety and reliability, as well as economic Reasonableness ； (4) Each pipeline should be as short as possible according to its starting and ending points, but it must still meet the requirements regarding pipeline flexibility ； (5) Each pipeline should be arranged as much as possible along the tower, with attention paid to achieving a \"good appearance\": Two options can be considered: one is to arrange each pipeline separately ； Second, arrange the pipes in groups (when the concentrated load resulting from this approach is high, approval from the equipment designer must be obtained) ； They are arranged in concentric circles along the outer wall of the tower on the pipeline side, or tangentially along the outer wall of the tower. What are the key points in the design of tower top pipelines? (1) The top of the tower is typically equipped with pipes for the oil and gas at the top of the tower, as well as pipes for venting and safety valves. The vent pipe at the top of the tower is generally installed atop the horizontal section of the highest point of the oil and gas pipeline at the tower top, and must comply with fire safety regulations ； (2) The medium in the oil and gas pipelines at the top of the tower is generally in gaseous form. The pipe diameter is large, the pipes should be as short as possible; they should have a gradual descent in elevation, bag-shaped sections should be avoided, and the pipes must possess a certain degree of flexibility ； (3) For each pipe running along the tower, a load-bearing support must be installed at the upper part, and guide supports must be placed at appropriate locations to prevent excessive stress on the pipe nozzles ； (4) The oil and gas pipelines at the top of the distillation tower are generally not insulated, only protected from heat ； If there are multiple heat exchangers connected to this pipeline, they should be arranged symmetrically in order to avoid flow imbalance ； (5) When the tower top features two stages of condensation, the piping layout should ensure that the condensate flows by gravity stage by stage. The main oil and gas pipe and the inlet branches for the condensation circuit should be arranged symmetrically to achieve uniform flow rates ； (6) When the top pressure of the tower is controlled by a thermal bypass, the tubes of this bypass system should be insulated, and their length should be kept as short as possible. The control valve for this system should be installed above the reflux tank, and the pipes must not form any \"pouch-like\" shapes to prevent liquid from accumulating there ； (7) The oil and gas pipelines at the top of the vacuum tower are welded directly to the tower opening instead of using flange connections, in order to reduce leaks. What are the specific requirements for the pipeline design on the side of the tower? (l) The pipes on the side of the tower generally include return pipes, feed pipes, side-line extraction pipes, stripping steam pipes, reboiler inlet pipes, and return pipes. To prevent liquid accumulation after the valves are closed, the valves on these pipes should be connected directly to the tower’s pipe openings. When there are two or more feed (or discharge) openings at the same angle on a feed (or discharge) pipe, some flexibility should be considered for that pipe ； (2) If there is a control valve on the pipeline from the side line of the fractionation tower to the stripping tower, its installation location should be as close as possible to the stripping tower, so as to ensure that there is a certain length of liquid column ahead of the control valve. The height of this liquid column must meet the requirements of the process. What are the characteristics of the pipeline design at the bottom of the tower? (1) The operating temperature at the bottom of the tower is generally high; therefore, when arranging the pipes at the bottom of the tower, their flexibility must meet the requirements of relevant standards or specifications. In particular, when the extraction piping at the bottom of the tower is connected to a pump, the piping should be short and have few bends; it must also possess sufficient flexibility to reduce the stress on the pump nozzle. The extraction line at the bottom of the tower should be led outside the tower skirt or base; flanges, instrument connections, and other piping fittings are strictly prohibited inside the tower skirt. The suction pipeline from the bottom of the tower to the bottom-mounted pump should not have any ‘pouch-like’ sections in its horizontal sections; it should slope downward continuously to prevent cavitation in the bottom-mounted pump. The isolation valve on the suction pipeline should be placed as close as possible to the tower body to facilitate operation ； (2) Unless it is a secondary reboiler, or when two or more reboilers operating in parallel require their heat load to be adjusted over a wide range, valves are generally not suitable for use on the pipes from the bottom of the tower to the reboilers. When a bottom reboiler is equipped with a centrifugal pump, its elevation must be such that the available net positive suction head meets the requirements of the centrifugal pump; simultaneously, the static head generated by the height difference between the liquid level at the bottom of the tower and the liquid level in the reboiler must be sufficient to overcome the pressure losses in the downcomer, reboiler, and riser. Therefore, the piping layout should meet the flexibility requirements while keeping the pipes short and minimizing the number of elbows. What requirements should be met for the layout of manholes on towers? (1) The manholes of the tower should be located within the tower’s operating area, at a place where entry into and exit from the tower are convenient, safe, and reasonable; they should preferably be situated in the same location. (2) When determining the location for the manhole, attention must be paid to the internal components of the tower; it should generally be placed in the bubbling zone above the tray, and not in the liquid dropping pipe or liquid receiving tank area of the tower ； (3) Manholes (or handholes) on the tower: generally, one is arranged every 3–8 tray levels ； (4) The height of the center distance between manholes above the platform surface is generally between 600 mm and 1000 mm, with 750 mm being the most suitable height ； (5) The manholes on a tower should be arranged on the same vertical line to ensure neatness and aesthetics. What are the requirements for the orientation of the tower’s nozzle? (1) The orientation of the pipe openings in the tower should meet the requirements of the working principles and structure of the internal components of the tower; during design, attention should be paid to the relative orientation between the overall structure of these internal components and the pipe openings ； The vapor outlet at the top of the tower is located in the middle of the tower’s top cover ； The reflux opening of the tower is generally located on the pipe side above the tray ； The gas feed opening is located above the tray, parallel to the downcomer ； The gas-liquid mixed-phase feed opening is located above the tray, with a distribution pipe in place ； The stripping steam inlet is located below the stripping tray, along with a gas distribution pipe. A extraction hopper should be installed in the circular area below the downcomer at the side-line product extraction port; for double-overflow tray columns with intermediate downcomers, the extraction port can be arranged at any angle there, and an extraction hopper should be provided ； The bottom extraction port is located in the middle of the bottom head cover, and an anti-vortex plate is provided; the extraction port should extend outside the tower’s skirt ； (2) For towers equipped with trays, manholes should be located along the tower diameter parallel to the tray overflow weirs; if this is not possible, they need not be parallel, but the horizontal distance between the manhole and the overflow weir should not exceed 50 mm. (3) The orientation of the manhole lifting mechanism and the placement of the ladder should be coordinated with each other, such that in the event of an accident, the direction in which the manhole cover can be closed smoothly is the same as the direction in which people can evacuate ； (4) The level gauge interface can be connected directly to the level gauge via a root valve, or it can be connected to the level gauge through a connecting pipe attached to the root valve. The level gauge interface must not be located within a 60° angle range opposite the feed inlet, unless the feed inlet is protected by an internal baffle. Baffles should be installed on the externally floating barrel-type level control nozzle that is connected directly to the tower. Devices such as level gauges, level control floats, and alarms are usually located within the tower platform or at the ends of the local platforms to facilitate maintenance ； (5) The pressure gauge interface should be located in the gas phase region of the tower, so that the pressure gauge readings are not affected by the liquid level head ； (6) Placement of sampling ports and temperature measurement ports: The gas-phase sampling ports and temperature measurement ports should be located away from the gas phase region of the tray liquid drop pockets, while the liquid-phase sampling ports and temperature measurement ports should be placed within the liquid holdup layer of the tray in the liquid drop tube area ； For liquid phase sampling tubes that are prone to crystallization, they should be positioned towards the tray ； (7) The positioning of the suspension column at the top of the tower should allow it to rotate to reach above the lifting points outside the platform, as well as the location of all access holes in the platform. In addition to showing the pipe openings, what other orientations does the equipment pipe opening diagram indicate? In addition to indicating the outlets for process and utility media, it should also show: (1) the location of the instrument connections, including for temperature, pressure, and level ； (2) Position of manholes, handholes, and suspension columns, position of skirt base exhaust vents ； (3) The orientation of the equipment’s foundation bolt holes or the orientation of the brackets ； (4) Position of lifting lugs, grounding plates, and nameplates ； (5) Position of internal ladders and reinforced supports at the bottom of the skirt. How to determine the fixed side of the support for a horizontal container? Identify from the pipes that need to be connected to this container the one that is most important (or poses the highest challenges) for flexible computing – for example, a pipe with large compensation requirements or a large diameter – and use this as a basis for determining the type of support. The position of the fixed support should facilitate the flexible calculation of the pipeline. What are the requirements for the orientation of the pipe openings in horizontal containers? (1) The distance between the liquid inlet and outlet on the equipment housing should be as large as possible. The liquid inlet pipe should be kept as far away as possible from the container level gauge interface ； (2) The level gauge interface should be located in a position that is easy for the operator to observe and maintain. Sometimes, to reduce the number of connections on the equipment, measuring devices such as local level gauges, level controllers, and level alarms can be installed on the header. The orientation of the level gauge outlet should be on the same side as the liquid level control valve assembly ； (3) Manhole covers connected by hinges (or suspension posts) should not interfere with other pipe openings or pipelines when opened ； (4) The safety valve connection port should be located at the top of the container. What are the general requirements for piping layout in horizontal vessels? The piping for containers (tanks) is relatively simple ； The piping arrangement in vertical vessels is generally similar to that in towers, with piping designed along the vessel walls; the valves on these pipes are also required to be directly connected to the openings ； This can prevent fluid accumulation. When arranging horizontal tank equipment, the tanks are generally placed perpendicular to the long axis of the pipe tray; as a result, pipes such as gas outlet pipes, safety valve outlet pipes, and liquid outlet pipes all face the pipe tray and are connected to the relevant components on it ； The supervisors are connected. The pipe emerging from the opening at the top of the container should be at a higher elevation than the main pipe it is connected to in the pipe tray, so as to allow it to be connected to the top of the main pipe. When the liquid outlet pipe at the bottom of the container is connected to the pump located beneath it, the elevation of the bottom of that pipe should not prevent people from passing by. (1) For the pipeline connecting the liquid outlet of a horizontal container to the pump inlet, if the piping is installed elevated within the channel, the minimum clear height is 2200 mrn ； (2) For the pipeline connected to the bottom outlet of a horizontal container, the minimum clear distance from the floor to the lowest liquid discharge point shall be 150 mm ； (3) When the outlet of the safety valve is connected to a closed pipeline system, accumulation of liquid should be avoided. The outlet pipe of the safety valve should slope downward at 45° in the direction of flow of the medium and connect to the top of the main closed pipe, without forming any \"pouch\" shape. If the safety valve is installed far away from the container, it is necessary to verify the pressure drop in the pipeline from the container to the safety valve inlet ； (4) The control valve assemblies for the pipes at the top of the storage tank are located on the platform ； (5) Platforms should be provided according to the layout of equipment and pipelines. What are the general requirements for the piping layout design of heating furnaces? (1) The piping layout of the heating furnace varies depending on the type of furnace. When arranging the piping for the heating furnace, its feed and discharge pipes, fuel system pipes, soot-blowing gas pipes, fire-suppression steam pipes, etc., should all be considered together ； (2) The inlet and outlet main pipes for the cylindrical furnace are usually arranged in a circular pattern around the furnace body, and can be supported on the floor or the furnace body. The ring main pipe should be located above the sight glass to facilitate its proper operation and maintenance ； (3) At the furnace outlet pipe elbow if necessary. Anti-vibration brackets should be installed at the three-way connections or where there is a significant change in diameter, or at the bottom portion directly below the furnace top ； (4) If a rupture disc is installed in the pipeline, its direction must not face the operation area or the equipment ； (5) The main control valve assemblies are usually installed between the pipe gallery and the furnace, taking into account the requirements for access paths ； (6) Valves on steam, fuel oil, or fuel gas pipelines should be installed on vertical pipes near the sight glass, to meet the requirements for regulation and maintenance ； (7) In cold regions, steam tracing should be applied to fuel oil pipelines in accordance with regulations ； (8) The pipes near the nozzle should have a detachable connection structure to facilitate cleaning and maintenance ； (9) Platforms and ladders should be provided at valves and viewing points that are frequently operated and located at higher positions ； (10) The discharge points for fuel pipelines shall be at least 15 m above the furnace, and should be connected to a collection system; they must not be discharged directly into the sewer system ； (11) The pipes connected to the furnace should be arranged as closely together as possible to facilitate support and achieve harmony. For aesthetic purposes ； (12) For the feed pipes of the heating furnace, the flow rate in each channel should be kept uniform ； For fully liquid-phase feed pipelines, flow control valves are generally installed in each branch to regulate the flow rate in those branches; otherwise, the pipelines should be arranged symmetrically. For inlet and outlet pipelines for gas-liquid phases, a symmetrical arrangement is necessary to ensure that the pressure drop across each branch is the same ； (l3) The annular oil line should have its thermal compensation calculated based on the maximum temperature, with the natural expansion of the pipeline being used to absorb its thermal expansion. What are the general requirements for the layout of fuel gas pipelines in heating furnaces? (1) A main distribution pipe should be installed for the fuel gas to ensure even distribution of fuel gas to each nozzle ； The fuel gas branch pipe extends from above the main distribution pipe to ensure that the fuel gas entering the nozzle does not contain water or condensed oil. At the end of the main fuel gas distribution pipe, there is a DN20 drain valve to facilitate flushing during commissioning and draining after shutdown for line cleaning, as well as to take samples for analyzing the oxygen content in the pipeline during startup. Two drain valves should be installed on the drain pipe to prevent leaks, and these valves can be operated from the ground or the platform. The main fuel gas cut-off valve should be located at a distance of 15 m from the heating furnace. (2) Installing a flame arrester on the fuel gas pipeline can prevent the spread of flames. Based on their working principle, flame arresters can be divided into dry-type flame arresters and safety water seals. Dry type flame arresters with multiple layers of copper wire mesh are generally used on the fuel gas pipes of heating furnaces in industrial production facilities. The flame arrester should be placed near the nozzle. The distance between the pipeline flame arrester and the burner should not exceed 12 m. In this way, the flame arrester is not exposed to severe explosive conditions, allowing its service life to be extended. How should the piping layout for shell-and-tube and double-pipe heat exchangers be considered? (l) When arranging process pipelines, attention should be paid to the flow direction of cold and hot streams; generally, the cold stream flows from bottom to top, while the hot stream flows from top to bottom ； (2) The piping layout should facilitate operation and not hinder the maintenance of the equipment ； (3) The base elevation of the heat exchange equipment shall ensure that the drainage pipe beneath it is at a distance of not less than 150 mm from the ground or platform surface ； (4) In the pipelines of heat exchange equipment, there should be only one high point and one low point to prevent the formation of \"air pockets\" or \"liquid pockets\" along the pipeline; a vent should be provided at the high point and a drain at the low point ； Within the heat exchange equipment area, pipeline intersections and detours should be avoided as much as possible ； Minimize the number of layers for overhead pipelines; generally, 2–3 layers are sufficient ； (5) The inlet pipes of two or more heat exchange units connected in parallel should be arranged in direct symmetry; for heat exchange units dealing with gas-liquid two-phase flow, symmetrical arrangement is necessary to achieve good heat transfer performance ； (6) The measuring instruments on the inlet and outlet pipes of heat exchange equipment should be installed near the operation area and in locations where they can be easily observed and maintained ； (7) For pipelines of condensable media connected to heat exchange equipment, or pipeline branches containing solid particles, their isolation valves should be installed on horizontal pipes, and measures should be taken to prevent the accumulation of liquid in dead corners ； (8) In cold regions, the supply and return pipes of outdoor heat exchange equipment should be equipped with drain valves and anti-freezing connection pipes. How should the piping layout be designed for heat exchange equipment arranged in groups? (1) Within the area where heat exchange equipment is arranged in groups, pipes may be laid on the floor or platform, provided that this does not hinder movement and operation ； (2) When there are no control valves or drain pipes on the pipeline, the clear height from the bottom of the pipe to the ground should be greater than or equal to 150 mm ； (3) The control valve assemblies should be arranged parallel to the heat exchange equipment; (4) The clear distance between the pipes connecting the heat exchange equipment arranged in groups should be greater than or equal to 650 mm ； (5) The piping layout should take into account the space required for removing the tube boxes and end caps of each heat exchange unit ； (6) The inlet and outlet pipes of multiple parallel heat exchange units should be arranged symmetrically. What are the requirements for the piping layout of vertical reboilers? (1) The pipeline must have sufficient flexibility to compensate for the thermal expansion of the equipment and pipelines under various operating conditions ； (2) When the outlet of the reboiler is connected to the outlet of a pipe in the same tower, and if the load conditions permit, it is advisable to install supports on the tower to hold the reboiler; moreover, the location and design of these supports should be such as to meet the displacement and load requirements resulting from the expansion of the tower and its pipes ； (3) When installing the piping, space should be left to allow for the removal of the reboiler bundle in place ； (4) For one-pass fixed-tube-sheet heat exchangers with expansion joints on the shell, the influence of these expansion joints should be taken into account when carrying out piping work, flexible analysis, and support design for the equipment ； (5) When the length-to-diameter ratio (L/D) of the reboiler is greater than 6.0, guide supports should be installed ； (6) When the valves and blind flanges of the reboiler are more than 3 m above the ground, a platform should be installed on the tower. What are the requirements for the piping layout of horizontal shell-and-tube reboilers? (1) Within the allowable stress range for thermal expansion, the downcomers and risers of the reboiler should be made as short and straight as possible, with as few elbows as possible, in order to reduce pressure drop ； (2) When the reboiler has two vapor rise ports, to ensure equal flow within its tubes, the vapor rise ports should be arranged symmetrically. When the diameters of the steam lift pipes differ and their arrangement is asymmetric, efforts should be made to make the resistance of these two pipe sections equal. Otherwise, the low flow rate in the steam rising pipe due to high resistance will result in uneven heat distribution ； (3) The liquid drawn out from the reboiler is a saturated liquid; if a pressure drop occurs in the piping system, the liquid will begin to flash, resulting in a two-phase flow of gas and liquid, which affects the operation and accuracy of control and measurement instruments. Therefore, when arranging the saturated liquid pipes, the basic principle is to minimize pressure drop, and to avoid any vertical upward sections before the measuring or control instruments ； (4) The inlet pipeline for the heating medium in the tube side of the reboiler is usually equipped with a temperature control valve and its associated valve assembly; these valves are generally installed on the floor or platform near the inlet to the tube side of the reboiler. What are the specific requirements for the piping design of air coolers? (1) In the oil and gas pipeline from the top of the distillation tower to the air cooler, a \"liquid pocket\" should generally not form. When there are no valves at the inlet and outlet of the air cooler or when a two-phase flow exists, the pipes must be arranged symmetrically to ensure uniform flow through each section of the air cooler ； (2) The inlet manifold of the air cooler should be connected close to the nozzles of the air cooler; if stress conditions or installation requirements dictate otherwise, the outlet manifold may not need to be connected close to the nozzles. The cross-sectional area of the manifolds should be greater than the sum of the cross-sectional areas of the branch pipes ； (3) When the air cooler inlet is filled with a gas-liquid two-phase flow, each branch pipe should be inserted into the inlet manifold from below ； To ensure uniform distribution of the fluid at the bottom of the collecting ducts ； At the same time, a shutdown drainage pipe is installed below the collecting duct, connected to the outlet pipe of the air cooler ； (4) The inlet pipe of the air cooler is at a high level ； If the distance is large, a dedicated pipe rack must be installed in between to support the pipes ； (5) The soft water return system of the wet air cooler is a gravity-fed pipeline; therefore, attention should be paid to the layout of the piping system, and there should not be too many bends. The return main should have a slope in the direction of flow of the medium ； (6) A semi-fixed steam purging connector is provided on the operating platform of the air cooler; its valve should be located in an easily accessible position, and care must be taken to consider the direction of the steam connector to ensure safe operation. What are the general requirements for pipeline design in pumps? (l) Cut-off valves should be installed on the inlet and outlet pipes of the pump, and the pipes must have sufficient flexibility in order to reduce the stress and torque exerted by the pipes on the pump’s inlet and outlet openings ； (2) The suction pipe of the pump must meet the pump’s requirements regarding NPSH; the pipe should be as short as possible, with few bends, and free of air pockets. If it is unavoidable, a vent valve should be installed at the high point ； (3) When the pump suction pipe is long, it is advisable to give it a certain slope (i=5‰) ； When the pump is lower than the container, it is advisable to have a slope leading toward the pump; when the pump is higher than the container, it is advisable to have a slope leading toward the container ； (4) A filter or temporary filter should be installed just downstream of the pipeline cut-off valve at the pump inlet, and a check valve should be installed at the pump outlet to prevent the reverse flow of fluid and thus the reversal of the pump’s impeller ； (5) The pump piping, provided that the process requirements are met. The valve handwheel must not interfere with the normal operation of the pump or with the space required for maintenance and inspection ； (6) The design of the inlet and outlet pipes of reciprocating pumps should take into account the effect of fluid pulsation. What are the types of protection wires for pumps? What is its function? There are 6 types of protection lines for pumps, whose purpose is to prevent damage to the pump and ensure its proper operation; the protection lines for pumps are selected based on the operating conditions. (1) Warm pump line – When transporting high-temperature oils with a medium temperature exceeding 200°C, a DN20–25 warm pump line should be installed if a backup pump is available ； (2) Low-flow line – When the pump’s operating flow rate is 30% below its rated flow rate, a low-flow line should be provided to allow the pump to operate properly at the lowest flow rate ； (3) Balance line – For liquids with a saturated vapor pressure at room temperature that is higher than atmospheric pressure, or liquids in the bubble point state, a balance line must be installed to prevent vapor from forming in the liquid entering the pump or bubbles from entering the pump and causing cavitation ； (4) Bypass line – used for the trial operation of the pump, or to keep the pump running when the main outlet valve is closed under abnormal operating conditions. Bypass valves equipped with flow-limiting orifices are generally installed in situations where the pressure difference before and after the valve is very high ； (5) Anti-condensation system – When transporting liquids with a high pour point or high freezing point that solidify at normal temperatures, anti-condensation systems should be installed in the standby pumps and pipelines to prevent them from getting clogged ； (6) Safety valve line – For positive displacement pumps such as electric reciprocating pumps, gear pumps, and screw pumps, a safety valve line is provided on the outlet side; when the outlet pressure exceeds a set value, the safety valve opens and the fluid returns to the pump inlet pipe. What are the general requirements for the piping layout of centrifugal compressors? (l) There are two types of centrifugal compressor housings: the vertically split type is used for high pressures, and there must be no pipes or other obstacles in front of the compressor ； The horizontal split type is used for medium and low pressures; there must be no pipes or other obstacles above its mechanism ； (2) The layout of the inlet and outlet pipes should, while meeting the requirements for thermal compensation and allowable stress conditions, minimize the number of elbows in order to reduce pressure loss ； (3) The inlet and outlet nozzles are generally oriented downward and supported at the center of the machine housing; during operation, their thermal expansion should be absorbed by the pipes ； (4) When the compressor nozzles installed in the plant have inlet and outlet at the top, detachable adapters must be provided on the inlet and outlet pipes for the maintenance of the compressor. What are the general principles for the piping layout design of reciprocating compressors? (1) The inlet and outlet pipes of the compressor should be short and straight, with as few elbows as possible; however, when the outlet pipe expands due to heat, the pipe should be made flexible ； (2) The pipeline layout should take into account the natural flow of the liquid to the liquid separation tank; when a \"liquid pocket\" forms in the pipelines, a drain at the lowest point should be provided to empty it ； (3) When multiple units are arranged side by side, the valves and instruments on their inlet and outlet pipelines should be installed in locations that are easy to operate and access ； (4) To prevent vibration in the inlet and outlet pipes of the compressor, necessary vibration analysis should be conducted. The pipeline layout should be as low as possible; the supports should be placed on the ground and use independent foundations, in order to increase the rigidity of both the supports and the pipelines ； (5) When the medium in the compressor is a flammable gas, plug seals, pipe caps, or flange covers should be installed on the vent valves at the lowest points of the pipes and at the highest points to prevent leaks. Additionally, the trenches surrounding the unit should be filled with sand to avoid the accumulation of flammable gases ； (6) When installing the inlet and outlet pipes of the compressor, it should not interfere with the movement of the maintenance crane ； (7) The pipes of the compressor should be arranged beneath the operation platform, to provide ample space around the unit for operation and maintenance.