Specifications for the installation of outdoor (indoor) fire hydrants

Technical Standards for the Installation of Interior Fire Protection Piping and Equipment 1. Scope These technical standards apply to the installation work of piping and equipment for automatic sprinkler systems and fire hydrant systems in civil and general industrial buildings. 2. Construction Preparation 2.1 Material Requirements: 2.1.1 Fire sprinkling pipes shall be selected in accordance with design requirements; generally, galvanized carbon steel pipes and fittings are used, with uniform galvanizing on both the inner and outer sides of the pipe walls, no rust or burrs, and no defects such as uneven thickness, misaligned joints, incomplete threads, or inaccurate angles in the components. 2.1.2 The pipes for the fire hydrant system shall be selected in accordance with design requirements; carbon steel pipes or seamless steel pipes are generally used, and the pipes must not have any bending, rust, thickening of the wall thickness, or uneven surfaces. 2.1.3 Alarm valves, operating valves, control valves, delay devices, water flow indicators, pump connectors, etc., of the fire sprinkling system. The specifications and models of the main components shall meet the design requirements; the accessories should be complete, the casting should be of proper quality, the surface should be smooth without cracks, and the operation should be smooth. There must also be a product qualification certificate issued at the time of manufacture. 2.1.4 The specifications, types, and operating temperature of the nozzles shall meet the design requirements; they should have a regular shape, intact threads, with no damage or looseness in the temperature sensing element, and no detachment or looseness in the fuse element. There is a product quality certificate. 2.1.5 The specifications and types of the fire hydrant box shall meet the design requirements, with a smooth and polished surface. The metal cabinet is free of rust or scratches, and the door opens smoothly. The box is square in shape, with all the necessary accessories inside. The plug valve has a regular shape, no cracks, operates smoothly when opened and closed, seals tightly, its sealing packing is in good condition, and it comes with a factory certification of conformity. 2.2 Main tools: 2.2.1 Tapping machines, grinding saws, bench drills, electric hammers, hand grinders, cordless drills, welding machines, electric pressure testing pumps, and other machinery. 2.2.2 Tools such as threading dies, pipe wrenches, vise grips, pressure clamps, chain pliers, hammers, steel saws, wrenches, nail guns, chain blocks, and electrical welding equipment. 2.3 Working Conditions: 2.3.1 The main structure has been inspected and accepted, and the site has been cleaned up. 2.3.2 The reference lines required for pipeline installation shall be determined and marked, such as the ceiling elevation, floor elevation, and the position lines of interior partition walls. 2.3.3 The equipment foundation has been inspected and meets the design requirements, thus satisfying the conditions for installation. 2.3.4 The scaffolding required for installing the pipelines shall be erected by professionals. 2.3.5 Check whether the position and dimensions of the pipe supports and reserved holes are correct. 2.3.6 The installation position of the sprinklers is determined according to the building decoration drawings; once the ceiling joists are installed, the elevation of the sprinklers is set based on the thickness of the ceiling material. When sealing the ceiling, make holes in the ceiling at the positions reserved for the sprinkler nozzles. 3. Operating Procedures 3.1 Process Flow: Preparation for installation → Installation of main pipes → Installation of alarm valves → Installation of vertical pipes → Installation of water flow indicators, fire pumps, high-level water spray pipes and branches, fire hydrants and their branches → Installation of boxes and pump connectors; pipeline pressure testing → Pipeline flushing → Installation of spray head branches (comprehensive system pressure testing and flushing) → Installation of throttling devices → Installation of alarm valve accessories, fire hydrant accessories, and spray heads → System testing with water flow 3.2 Preparation for Installation: 3.2.1 Thoroughly study the drawings; select materials in accordance with the specific measures outlined in the construction plan, technical and safety instructions; measure dimensions, draw sketches, and carry out prefabrication work. 3.2.2 Verify the relevant professional drawings to check whether there are any overlaps or improper arrangements of the coordinates and elevations of various pipelines; promptly discuss these issues with the designers to find solutions and carry out the necessary consultation procedures. 3.2.3 Check whether the embedded parts and reserved holes are accurate. 3.2.4 Check whether the pipes, pipe fittings, valves, equipment, and components meet the design requirements and quality standards. 3.2.5 A reasonable construction sequence should be arranged to avoid interference from concurrent operations of different tasks, which could affect the construction process. 3.3 Installation of main pipes: 3.3.1 For spray pipes, galvanized pipe fittings are generally required (for main pipes with a diameter of over 100 mm, welded flanges are used if galvanized pipe fittings are not available; after pressure testing, markings are made and the pipes are removed for galvanizing). Pipes that require galvanizing should be made of carbon steel pipes or seamless steel pipes; painting or contaminating the pipes is not allowed before galvanizing. Construction should be scheduled first for pipes that need to have their galvanizing removed or installed. 3.3.2 For flange-connected spray main pipes, the length of each pipe section should not exceed 6 m; several such sections can be connected together in straight sections, and chain hoists can be used for installation, but the overall length should still not be too great. It can also be straightened first, and then lifted one by one in sequence. When lifting, lift one end of the pipe first, and once it is stable, lift the other end. 3.3.3 When tightening the flanges for pipeline connection, check whether the flange surfaces are clean, and use rubber gaskets with a thickness of 3–5 mm. The specifications of the flange bolts shall comply with the regulations. The fastening bolts should first be tightened at the most unfavorable points, and then tightened symmetrically in sequence. The flange interface should be installed in a location that facilitates easy installation and removal. 3.3.4 The installation of the main pipes in the fire hydrant system shall use piping materials in accordance with design requirements; carbon steel pipes or seamless steel pipes shall be selected based on pressure requirements. 3.3.4.1 Before welding, the pipe joints should be cleaned of loose rust, dirt, and grease. 3.3.4.2 Gas welding shall be used when the wall thickness is ≤ 4 mm and the diameter is ≤ 50 mm ； Welding should be used when the wall thickness is ≥45 mm and the diameter is ≥70 mm. 3.3.4.3 For welding pipes of different diameters, if the difference between the two diameters is no more than 15% of the smaller diameter, the end of the larger pipe can be tapered and welded to the smaller pipe. If the difference between the two pipes exceeds 15% of the smaller pipe diameter, a reducer should be fabricated for welding. 3.3.4.4 No branch pipes shall be welded on the butt welds of the pipes, and no welds shall be installed at the locations of supports and hangers. 3.3.4.5 There shall be no joints (threaded or welded) at the points where pipes pass through walls; anti-freezing measures shall be in place where pipes pass through expansion joints. 3.3.4.6 When welding open ends of carbon steel pipes, the welds should be staggered, and the welds should be oriented in a direction that facilitates observation and maintenance. 3.3.4.7 When welding pipes, spot-weld at least three points first; then, after checking that the position, direction, and diameter changes of the reserved openings are correct, align the pipes properly before proceeding with welding. Finally, tighten the clamping elements and remove the temporary fixing devices. 3.4 Installation of the alarm valve: It should be placed in a visible and easily accessible location, at a height of approximately 1 meter above the ground. The floor at the alarm valve should have drainage measures, and the ambient temperature should not be lower than +5°C. When assembling the alarm valve, it should be done in accordance with the product instructions and design requirements; the control valve must be equipped with an opening/closing indication device, and the valve should operate in a normally open state. 3.5 Installation of fire sprinkling systems and fire hydrant risers: 3.5.1 When the riser is installed concealed within a shaft, it should be fixed using clamps mounted on the iron components pre-installed in that shaft; the supports and hangers at the bottom of the riser must be secure to prevent it from falling. 3.5.2 When the riser is installed exposed, holes should be provided in each floor slab, allowing the riser to pass through the structure thereby reducing the number of riser connections. 3.6 Installation of fire sprinkling main and branch pipes in layers: 3.6.1 The branch connection openings for the pipes should be pre-made before lifting; for threaded connections, tees are used to mark the locations of these openings, while for welded connections, iron pipe collars can be welded onto the main pipes, and after straightening them, they can then be lifted. All reserved openings have been fitted with temporary plugs. 3.6.2 Pipes that require galvanizing should be pressure-tested before the installation of other pipes, removed, galvanized, and then reinstalled. 3.6.3 The installation of pipes in the corridor ceiling and the location of ventilation ducts must be coordinated properly. 3.6.4 For connections of spray pipes with different diameters, spacers should not be used; instead, reducer couplings should be employed. Spacers must not be used on elbows – reducer elbows should be used instead. At tees, a maximum of one spacer can be used, while at crosses, a maximum of two spacers can be used. 3.6.5 The upward-facing nozzles can, where feasible, be installed in sequence with the branch main pipes. Sprinklers that spray upward should also be installed first in those areas that are difficult to access after the other pipes have been installed. 3.7 Installation of fire hydrants and branch pipes: 3.7.1 The fire hydrant housings must meet the design requirements (the materials can include wood, iron, aluminum alloy, etc.), and the valve types may include single-outlet and double-outlet with dual control mechanisms. Products must have a manufacturing license and certification issued by the fire department before they can be used. 3.7.2 The branch pipes of the fire hydrant should have their outlets positioned based on the coordinates and elevation of the hydrant valve; after verification, the hydrant box should be secured. Once the box is properly aligned and fixed, the check valve should be installed. When the hydrant valve is mounted on the inside of the box, it should be located on the side where the box door opens, and the box door must open smoothly. 3.7.3 When the fire hydrant box is installed on a lightweight partition wall, reinforcement measures shall be provided. 3.8 Installation of water flow indicators: They are generally installed on the horizontal branch main pipes on each floor, or on the branch main pipes in a certain area. It should be installed horizontally; the inclination should not be too great to ensure smooth movement of the blades. There must be a straight pipe section with a length of 5 times the diameter of the installation pipe in front of and behind the flow indicator. When installing, make sure that the direction of the water flow matches the arrow on the indicator. Domestic products can be directly installed on threaded tees, while imported products can be secured at the openings of the main pipes using fixing clamps. Flow indicators are suitable for installation on pipes with a diameter of 50–150 mm. 3.9 Installation of fire pump: 3.9.1 The specifications and models of the pump shall meet the design requirements; the pump should have a self-priming suction function, its foundation shall be constructed in accordance with the design drawings, and vibration dampers shall be installed on the suction pipe. Pressure pumps may not require vibration-damping devices, but constant-pressure pumps should have such devices; noise-reducing measures should be installed at the inlet and outlet, and a slow-closing check valve is advisable to be installed at the pump outlet. 3.9.2 The installation of water pump piping should be carried out after the water pump has been positioned, leveled, and secured. Pump equipment must not bear the weight of the pipes. The installation sequence is as follows: start with the check valve; secure the valve to the water pump one by one. First, fasten the flange of the pipe connected to the water pump to the valve’s flange, then use a plumb bob to align everything properly. Measure the dimensions of the pipe, spot-weld it to this flange first, then loosen and remove the flange before welding it in place. After it cools down, connect it to the valve, and finally weld the other end of the pipe to it. 3.9.3 The piping flanges shall match those of the water pumps and valves; the direction of the valve installation handwheels shall facilitate operation, the elevations shall be consistent, and the piping shall be arranged neatly. 3.10 Installation of high-level water tanks: They should be in place before the structure is completed, and a water filling test should be conducted. When fire-fighting water tanks are shared with other types of water tanks, it must be ensured that the fire-fighting water is not used for other purposes, with a reserve of 10 minutes’ worth of fire-fighting water available. When used for domestic purposes, the water should be kept in a flowing state at all times to prevent it from deteriorating in quality. A check valve should be installed on the fire water outlet pipe (to prevent water from entering the tank when pressure is applied for firefighting purposes). All tank nozzles should be prefabricated; if welding is carried out on site, reinforcement plates should be welded to the tank. 3.11 Installation of water pump connectors: The specifications should be determined according to the design; there are three types: wall-mounted, above-ground, and underground. Its installation location should be clearly marked, the valve should be easily accessible for operation, and there should be no obstacles near the coupler. The safety valve should be set at a pressure corresponding to the system’s operating pressure, in order to prevent excessive pressure from fire trucks from damaging the indoor piping network and components; the coupling should be equipped with a drain valve. 3.12 The pressure testing of fire protection pipelines can be carried out in layers and sections. An exhaust device should be installed at the highest point when filling the pipes with water, and a pressure gauge should be placed at both the highest and lowest points. After filling the pipes with water, check for any leaks; if there are leaks at joints such as flanges or valves, tighten them before applying pressure. If leaks occur after pressurization, mark them and address the issue after depressurizing the system. Drainage treatment when necessary. During winter pressure testing, the ambient temperature must not be lower than +5°C; in summer, it is best not to use external water supply lines to avoid condensation. Complete the acceptance procedures promptly after the pressure test is successful. 3.13 Pipe flushing: Fire protection pipes can be continuously flushed after the pressure testing is completed. Before flushing, remove the flow-reducing orifice plates and filtering devices from the system; once the water quality for flushing is satisfactory, reinstall them. The water used for flushing must have a place to be discharged, and it must not cause damage to other finished products. 3.14 Installation of the spray head branch pipe refers to the final section of the branch pipe for ceiling-mounted spray heads; this section cannot be installed simultaneously with the main branch pipes, and must be carried out in parallel with the ceiling installation work. After the ceiling joists are installed, the elevation of the openings for the sprinklers is determined based on the thickness of the ceiling material. The coordinates of the sprinklers are set according to the ceiling installation drawings, so that the locations of the branch pipe openings are clearly defined. The diameter of all branch pipes is 25 mm; the ends are fitted with 25 mm × 15 mm reducer fittings, and these fittings are set at the same level as the ceiling finish layer, with tension wires used for installation. A clamping piece should be installed within 100 mm of the elbow at the end of the branch pipe to prevent the sprinkler head from making loose contact with the ceiling and shifting up or down. After installing the branch pipe, an opening must be left and tightened with a screw plug. Prepare for system pressure testing. 3.15 Pressure testing of the spraying system: Conduct pressure testing on the system before installing the ceiling. To avoid delaying the ceiling installation process, the testing can be carried out in stages. After the testing is complete, flush the pipes; once they pass the inspection, the ceiling can be installed. Make a 30mm hole at the pipe clamp opening in the ceiling material to expose the reserved opening; after the ceiling installation is complete, remove the plug and install the spray head. 3.16 Throttling devices: In high-rise fire protection systems, where the flow rate at the sprinklers and fire hydrants on lower floors is too high, devices such as pressure-reducing orifices or throttle tubes can be used to balance this flow. The pressure relief orifice plate should be installed on a horizontal pipe section with a diameter of at least 50 mm; the diameter of the orifice should be no less than 50% of the diameter of the pipe section in which it is installed. The orifice plate must be placed on a straight pipe section located downstream of the bend in the flow path, with a distance from the bend that is at least twice the diameter of the pipe section in which it is installed. When using a throttle tube, its length should not be less than 1 m. The diameter of the throttle tube shall be selected according to Table L-17. Throttle tube diameter Table 1-17 3.17 Installation of alarm valve accessories: This should be carried out before delivery. The delay device is installed in closed-head automatic sprinkler systems and serves to prevent false alarms. It can be installed according to the instructions and assembly diagram; it should be installed on the signal pipe between the alarm valve and the hydraulic alarm bell. The hydraulic alarm bell is installed near the alarm valve. Pipes connected to the alarm valve should be made of galvanized steel pipes. 3.18 Installation of fire hydrant accessories: It should be carried out before handover. Fire hoses should be folded and placed on hooks, or rolled up and tightly stored in boxes; fire nozzles should be placed vertically inside the boxes, while self-rescue nozzles and hoses should be hung on brackets or placed at the bottom of the boxes. For the connection of fire hoses and nozzles using quick connectors, 14# wire is generally used for binding in two layers, with each layer comprising no fewer than two turns; when clamps are used, an additional layer of wire is added on the inside. When electric control buttons are installed, attention should be paid to coordinating the construction with the electrical team. 3.19 Sprayer installation: 3.19.1 The specifications, types, and operating temperature of the sprayers must meet the design requirements. 3.19.2 The protected area covered by the sprinklers, the spacing between them, as well as the distance from the walls and other structures, must comply with the specified requirements. 3.19.3 The wings of the nozzles should be installed in rows in a uniform manner. The guard plate should be attached tightly to the ceiling, and the sprinklers in a single row in the corridor should be installed horizontally on both sides. 3.19.4 A special wrench (fork-type) should be used to install the sprinkler nozzles, and polytetrafluoroethylene tape is recommended as packing material to prevent damage and contamination of the ceiling. 3.19.5 When installing water curtain nozzles, attention should be paid to directing them toward the objects to be protected; nozzles of the same diameter should be installed on the same distribution branch pipe. 3.20 The installation of the fixing brackets for the spraying pipes shall comply with the design requirements. 3.20.1 The location of supports and hangers shall be such as to not interfere with the spraying effect of the nozzles. Generally, the distance between the hanger and the sprinkler should be greater than 300 mm; for round steel hangers, this distance can be as low as 70 mm. 3.20.2 To prevent excessive shaking of the pipes when the nozzles discharge water, anti-shaking fixing brackets should be installed on both the main pipes and vertical pipes. The main pipe or stratified main pipe can be installed in the middle of a straight pipe section, at a distance of no more than 12m from the main pipe and the end. When the length of a single rod hanger is less than 150mm, it is not necessary to use anti-vibration fixing brackets. 3.20.3 The anti-vibration fixing bracket shall be able to withstand the total weight of the pipes, components, valves, and water inside the pipes, as well as 50% of the horizontal pushing force, without suffering damage or permanent deformation. The riser shall be equipped with anti-sway fixing brackets in two directions. 3.21 When automatic devices are used for setting up deluge and water curtain sprinkler fire extinguishing systems, they should be installed at the front with devices at the back. Generally, in areas without heating facilities or where the ambient temperature is above 70°C, a dry automatic sprinkler system should be used. Before installing the nozzles in such a system, pressure testing and flushing must be carried out. Use an air compressor to purge the pipeline under certain conditions. 3.22 The water testing of the fire protection system shall meet the conditions specified by the fire department for testing. The fire pump should be connected to the power supply and have been tested; the pressure and flow rates at the sprinklers and fire hydrants at the most unfavorable locations must meet the design requirements. 4. Quality Standards 4.1 Assurance Items ； The position, spacing, and orientation of the nozzles in automatic sprinkler and water curtain fire suppression systems must comply with the design requirements and construction specifications. Inspection method: Inspection by observation and comparison with drawings and construction specifications. 4.2 Basic requirements: The installation of box-type fire hydrants should be such that the nozzle faces outward, and the distance between the valve and the ground as well as the distance from it to the box walls must comply with the specifications set out in the construction standards. The hoses are tightly tied to the fire hydrants and quick connectors, folded, and hung on trays or brackets. Inspection method: Visual inspection and measurement. 4.3 Permissible deviation items: 4.3.1 The distance from the center of the fire hydrant valve to the ground should be 1.2 m, with a permissible deviation of 20 mm. The valve is 140 mm from the side surface of the box and 100 mm from the inner rear surface of the box, with a permissible deviation of 5 mm. 4.3.2 The pipes of automatic sprinkler and water curtain fire protection systems shall have a slope. The water filling system should be not less than 0.002 ； The inflation system and branch pipes shall be not less than 0.004. 4.3.3 The distance between the hanger and the sprinkler should be no less than 300 mm, and the distance from it to the end sprinkler should not exceed 750 mm. 4.3.4 Hangers should be installed on the pipe section between adjacent sprinklers; when the distance between adjacent sprinklers is not more than 3.6 m, one hanger can be used ； Less than 1.8m, sectional installation is allowed. Testing method: Measure with a ruler and a level. 5. Protection of finished products 5.1 After the construction of the fire protection system is completed, protective measures must be put in place for the equipment components in various areas to prevent them from being damaged or causing water leaks, which could damage the finished decorations. 5.2 The accessories of alarm valves, the items inside fire hydrant boxes, and the instruments in various locations should all be properly managed to prevent loss and damage. 5.3 When there is a conflict between the installation of fire protection pipelines and civil engineering works or other pipelines, it is not allowed to make any modifications without authorization; instead, design revisions must be carried out through proper consultation to resolve the issue. 5.4 The sprinkler heads must not contaminate or damage the ceiling decoration surface during installation. 6. Quality issues that require attention 6.1 Severe modifications to the spraying pipes. The installation of various specialized processes is not well coordinated; there should be an overall plan. 6.2 There is leakage at the sprinkler head. The ceiling was sealed before systematic pressure testing, resulting in leaks after water was supplied. Before sealing the ceiling, pressure testing must be carried out, and the procedures for inspecting concealed works must be completed. 6.3 The sprinkler head is not firmly attached to the ceiling, and the protective ring is tilted ； Since no clamping device was used to secure the elbow at the end of the branch pipe, the size of the branch pipe was inaccurate, resulting in the protective plate not being in proper position. 6.4 The nozzles are not arranged in rows or columns. Due to installation without tensioning wires. 6.5 The water flow indicator is not sensitive enough. Poor contact is caused by the opposite installation direction or oxides on the electrical contacts. 6.6 The water pump connector cannot build pressure. This is caused by the valve not being opened, the check valve being installed in the wrong direction, or a blind flange not having been removed. 6.7 During the testing of the open-type spraying system, the nozzles became clogged while in operation. Rinsing or purging should be performed before installing the nozzles. 6.8 The fire hydrant box door does not close properly. It is caused by misalignment during installation or deformation due to insufficient strength of the box door. 6.9 The fire hydrant valve is not closed properly. It is caused by the main pipeline not being thoroughly flushed and debris on the valve seat. 7. Quality records 7.1 There shall be factory certificates of conformity for the materials and equipment, manufacturing licenses from the producers, as well as test reports issued by authorized testing institutions. 7.2 On-site acceptance records for materials and equipment. 7.3 Pre-inspection records for fire protection ducts 7.4 Pre-inspection records for fire protection main and branch pipes 7.5 Pre-inspection records for sprinkler main and riser pipes 7.6 Pre-inspection records for sprinkler branch pipes 7.7 Individual pressure testing records for fire protection and sprinkler pipes 7.8 Pressure testing records for fire protection and sprinkler systems 7.9 Inspection records for concealed parts of fire protection and sprinkler pipes 7.10 Flushing records for fire protection and sprinkler systems 7.11 Water-testing and commissioning records for fire protection and sprinkler systems

There are specific **standard installation procedures for fire protection pipes and equipment; you can look them up

In a few places I visited recently, I found that the fire hydrants were blocked by walls… they couldn’t be used at all. Ugh, there’s indeed a problem with this setup