1 pipe general requirements
(1) The clearance height, channel width, and base elevation of the piping shall comply with the provisions of Chapter 3 of the Design Regulations for the Layout of Chemical Plant Equipment (HG20546.2).
(2) Pipeline layout design shall be carried out in accordance with the provisions of the country's current standard.
(3) pipelines as far as possible overhead laying, if necessary, can also be buried or ditch laying.
(4) pipeline layout should be considered operation, installation and maintenance convenience, does not affect the crane operation. Pipes should not be laid in the area where the building is installed.
(5) Pipeline layout design should be considered to facilitate the design of the hanger, so that the pipeline as close as possible to existing buildings or structures, but should avoid the flexible components to withstand greater load.
(6) Where conditions are met, the pipes shall be arranged in a row. The tube of the bare tube is aligned with the bottom of the tube in order to design the bracket.
(7) no insulation layer of the pipe without care or support. Large diameter thin-walled bare tube and insulated pipe should be supported by pipe support or support.
(8) Pipes that transport corrosive media above the passageway or rotating equipment shall not be provided with connection points which may cause leakage, such as flanges or threaded connections.
(9) Pipes shall be fitted with a casing for the isolation of highly toxic or explosive media. The voids in the casing shall be filled with non-metallic flexible material. Pipes on the weld should not be in the casing, and from the casing port is not less than 100mm. Pipeline wear roof, there should be rain measures.
(10) fire water and cooling water mains and sewers are generally buried laying, the outer surface of the tube should be taken in accordance with the relevant provisions of anti-corrosion measures.
(11) Buried piping should take into account the impact of vehicle loads, the distance between the roof and the road surface is not less than 0.6m, and should be below the depth of permafrost.
(12) For "no bag", "with slope" and "with liquid seal" and other requirements of the pipeline, should be in strict accordance with the requirements of PID piping.
(13) When connecting the branch pipe from the horizontal gas main pipe, it should be taken out from the top of the main pipe.
2 parallel pipe spacing and installation space
(1) parallel to the pipeline between the net distance should meet the pipe welding, insulation and installation of components and maintenance requirements. The clearance between the projections on the pipe shall not be less than 30 mm. Such as the outer edge of the flange and the adjacent pipe insulation between the outer wall of the distance or between the flange and flange clearance.
(2) no flange is not insulated between the distance between the pipeline should meet the requirements of pipeline welding and inspection, generally not less than 50mm.
(3) the lateral displacement of the pipeline should be appropriate to increase the distance between the pipeline.
(4) The most prominent part of the outer wall of the pipe protruding part or the pipe insulation layer shall not be less than 100mm away from the pillars of the frame or frame, and the space required for the bolts shall be taken into account.
3 pipe exhaust and drainage
1, due to the formation of high or low pipeline layout, should be set to exhaust and drain:
(1) the high point of the minimum diameter of the exhaust DN15, low outlet diameter of the smallest DN20 (DN15 for the head, the drain for the DN15). High viscosity of the media exhaust, drain the smallest diameter DN25.
(2) the high point of the gas pipe exhaust can not set the valve, the use of threaded cap or flange cover closed. In addition to the pipe on the tube, DN less than or equal to 25 of the pipeline may not set high point exhaust.
(3) non-process high point exhaust and low discharge port can not be expressed on the PID.
2, the process requirements of the exhaust and drain (including the equipment connected) should be set on the requirements of the PID.
3, the height of the exhaust requirements, should be consistent with the current national standard "petrochemical enterprise design fire safety norms" (GB50160) requirements.
4, toxic and flammable and explosive liquid pipeline discharge points shall not access the sewer, should access the closed system. Ventilated air heavier than air should take into account the impact on the operating environment and personal safety protection.
4 pipe weld position
(1) The distance between the center of the pipe butt weld and the bending point of the pipe shall not be less than the outer diameter of the pipe and not less than 100mm.
(2) the distance between two adjacent butt welds on the pipe shall be not less than 3 times the pipe wall thickness, the length of the short pipe shall be not less than 5 times the pipe wall thickness and not less than 50mm; for pipes with DN greater than or equal to 50mm , The distance between the two welds should not be less than 100mm.
(3) The pipe weld shall not be within the scope of the pipe. The distance between the edge of the weld and the edge of the bracket shall be 5 times greater than the width of the weld and shall not be less than 100 mm.
(4) should not be in the pipe weld and its edge on the hole and take over.
(5) steel plate welded pipe longitudinal weld should be placed in easy maintenance and observation position, and not in the horizontal tube at the bottom.
(6) For joints with reinforcing or supporting rings, the joints of the reinforcement ring or support ring shall be offset from the longitudinal welds of the pipe and not less than 100 mm. Reinforcement ring or support ring pipe ring weld should not be less than 50mm.
5 pipeline hot and cold compensation
(1) The displacement, force and moment of the pipe produced by the thermal expansion or cold shrinkage must be carefully calculated and preferentially absorbed by the natural geometry of the pipe arrangement. The force and torque acting on the equipment or machine pump interface shall not be greater than the allowable value.
(2) When the self-compensating capacity of the pipeline can not meet the requirements, the compensating element shall be installed in the proper position of the piping system, such as "Π" elbow; when the conditions are restricted, the bellows expansion joint or other form of compensator shall be used. Reasonable selection of calculation results, according to the standard requirements to consider setting the fixed frame and guide frame.
(3) when the need to reduce the force and torque, allowing the use of cold-drawn measures, but the important sensitive machines and equipment to take over cold pull.
6 valves are generally required
(1) the valve should be located in easy to operate, easy to install, repair the place. The valves on the piping (eg piping on and out of the device) should be arranged centrally to facilitate the installation of the operating platform and ladders.
(2) Some valve positions have the requirements of the operation and the requirements of the lock, according to the PID instructions and layout.
(3) the tower, the reactor, vertical containers and other equipment at the bottom of the pipeline valve, should not be arranged in the block.
(4) Manual valves that need to be operated according to the instructions of the local instrument should be located close to the local instrument.
(5) regulating valve and safety valve should be arranged on the ground or platform for easy maintenance and commissioning of the place. The trap shall be arranged in accordance with the provisions of Chapter 15 of the Design Regulations for the Layout of Chemical Plant Pipes (HG / T20549.5).
(6) fire hydrant or fire with the valve, should be located in the event of a fire can be safely close to the location.
(7) buried pipeline valves to be located in the valve wells, and left maintenance space.
(8) The valve should be located where the heat displacement is small.
(9) When there is a bypass or biased transmission part on the valve (eg gear drive valve), there should be sufficient installation and operation space for bypass or offset parts.
7 Valve position requirements
(1) The stem centerline of the valve on the riser shall be installed at a height of 0.7 to 1.6 m above the floor or above the platform, and the DN40 and the following valves may be arranged below the height of 2 m. When the position is too high or too low, a platform or a control device, such as a sprocket or extension rod, shall be provided for ease of operation.
(2) very few less frequent operation of the valve, and its operating height from the ground is not greater than 2.5m, and inconvenience to another permanent platform, the application of portable ladder or mobile platform allows people to operate.
(3) the valve around the operating platform around the center of the hand wheel from the operating platform edge should not be greater than 400mm, when the stem and hand wheel into the platform and the height of less than 2m, it should not affect the operator's operation and traffic safety.
(4) adjacent to the layout of the valve, the handwheel between the net distance should not be less than 100mm.
(5) The valve stem of the valve should not be mounted vertically or tilted downward.
(6) installed in the trench or valve wells often operate the valve, when the hand wheel below the cover below 300mm, should be installed extension rod, so that under the cover within 100mm.