How to design pipeline layout

How to design pipeline layout

First, a set of beautiful pipe layout pictures, look at the design of other families, do not be blinded by the beautiful pipe layout pictures photos.

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Want to know how to design high quality piping arrangements? You also want to design such a work? Then the following knowledge can not miss it. Without further ado, let’s take a look at how piping design should be carried out.

Requirements for piping layout design

  • (1) piping layout design should be in line with the process piping and instrumentation flow chart requirements.
  • (2) piping layout should be integrated planning, do safety by, economic and reasonable, to meet the construction, operation, maintenance and other surface requirements, and strive to neat and beautiful.
  • (3) determine into the device (unit) pipeline position and laying type, should do internal and external coordination.
  • (4) plant-wide pipeline laying within the plant, should be with the plant devices (units), roads, buildings. Coordination of structures, etc., to avoid pipelines surrounding the device (unit), reduce the pipeline and railroad, road crossings.
  • (5) pipeline should be overhead or paid; really need, buried or laid in the pipe trench.
  • (6) the pipeline should be arranged in a set row. Pipeline should be laid pipe rack or pipe pier.
  • (7) pipe rack, pipe pier layout pipeline, it is appropriate to make the pipe rack or pipe pier subject to vertical load, horizontal load balance;.
  • (8) plant-wide pipe racks or piers (including crossing culverts) should be left with a margin of 10%-30% and their loads should be taken into account. The main corridor pipe rack of the plant should be left with a margin of 10-20% and its load should be taken into account.
  • (9) conveying medium distance, angle, height difference and other special requirements pipeline and diameter pipeline layout, should be in line with the equipment layout design requirements.
  • (10) pipeline layout should prevent equipment, pumps and their internal components installation, maintenance fire vehicle traffic.
  • (11) pipeline layout should make the pipeline system with the necessary flexibility. Ensure that the pipeline flexibility and pipeline equipment, machine pump orifice action torque over the allowable value of inert condition, should make the pipeline short, less components.
  • (12) the pipeline planning should be considered with its support point settings. It is desirable to use the pipeline self-shape up to self compensation.
  • (13) pipeline arrangement should be done step high or step low, reduce the gas bag or liquid bag. Avoid should be set up according to the operation and maintenance requirements for emptying and purging. Pipeline arrangement should reduce the appendix.
  • (14) gas-liquid two-phase flow pipeline by road two-way or road, pipeline arrangement should consider weighing sex or meet the requirements of pipeline and instrument flow chart.

Device (unit) layout design regulations

Design principles

(1) The project transformation part of the principle of maximizing the use of the original facilities.
(2) To meet the process requirements

  • Equipment (unit) layout should take full account of the process system requirements for equipment elevation differences and pump net suction head.
  • (NPSH) and the process control requirements for equipment layout, in addition to prevent coking, blockage, control.
  • In addition, in order to prevent coking, blockage, control temperature drop, pressure drop and other related equipment with process requirements as close as possible to the layout.

(3) Safe production

  • The layout of the equipment (unit) should take into full consideration the requirements of fire and explosion prevention safety distance between equipment and pumps.
  • The safety distance between buildings and adjacent devices (units) outside the boundary area with the safety distance requirements of the equipment or building.
  • Safety distance between devices (units); devices (units) layout should be set up through the channel and the boundary area around the ring channel.
  • Connected to ensure the accessibility and operability of firefighting operations.

(4) Convenient equipment installation and maintenance

  • Large equipment such as reactors, often, decompression tower and fractionation tower should be arranged against the road side, both favorable.
  • Equipment grouping on site, but also convenient for its lifting; through the channel to create for each equipment installation and maintenance.
  • conditions. In addition, set up a number of access points to create conditions for the maintenance of certain equipment (such as compressors).
  • Equipment layout should also be fully considered equipment maintenance (such as shell and tube heat exchanger ) space required and solid material handling.
  • The required work surface.

(5) Saving

  • Device (unit) layout should be in accordance with the “smooth flow, compact layout” principle, to reduce the device covers an area.
  • Optimize the equipment spacing, reduce the pipeline round trip; for large diameter pipeline, high cost (such as high material) pipeline, should be as short as possible to save investment.
  • Should be as short as possible, in order to save investment.

The positioning principle of equipment arrangement

  • (1) Horizontal vessels: centerline of the foundation
  • (2) Tower and vertical vessels: centerline
  • (3) heat exchanger: foundation centerline (frame upper layer); pipe range mouthpiece centerline (ground layer)
  • (4) horizontal pumps: pump end foundation
  • (5) Vertical pumps: pump centerline

The width of the passage in the device

  • (1) Fire road for vehicles: minimum 4000mm
  • (2) maintenance, maintenance road: minimum 4000mm
  • (3) operation channel: minimum 800mm
  • (4) Connecting channel: minimum 800mm
  • (5) maintenance of the inner edge of the fire road turning radius should not be less than 9m.

The net height of the channel in the device

  • (1) truck channel headroom requirements: minimum 4500mm
  • (2) Factory main road headroom requirements: minimum 5000mm
  • (3) Railway headroom requirement: minimum 5500mm
  • (4) Fire truck access headroom requirements: minimum 4500mm
  • (5) Operation channel headroom: minimum 2100mm

Foundation elevation

  • (1) meet the process requirements.
  • (2) tower and ground level vertical equipment foundation height should generally take: H = 200mm.
  • (3) horizontal equipment and cold exchange equipment foundation elevation in addition to meet the process requirements, to meet the piping requirements of the minimum height shall prevail.
  • (4) machine pump foundation height should generally take H = 200mm, but for large machine pump in the pump room, such as operation, maintenance height is too high can be appropriately reduced to H = 100mm foundation height.

Structural class settings

  • (1) main bridge: column spacing 6000mm, span spacing 6000/9000/12000mm mainly. Main girder:EL+4500mm,EL+6500mm. side girder:EL+3500mm,EL+5500m,EL+7500mm.
  • (2) Cold exchange frame: column spacing 6000mm, 6500mm. span 9000mm.

The tower and vertical container platform settings

  • (1) Platform width generally 1000~1600mm, maximum 1800mm, minimum 800mm (according to the pipeline planning requirements).
  • (2) The maximum layer spacing: 6000~8000mm; the minimum layer net height 2300mm.

Equipment and machine maintenance facilities

  • (1) Main fan, compressor: bridge cranes are installed in the plant.
  • (2) heat exchanger: heat exchanger arranged on the ground and intermediate levels are considered to use machines and lifting beams for installation. Inspection, arranged on the top layer of the structure of the heat exchanger to consider the use of cranes; lifting side of the platform railing for the active railing.
  • (3) Tower. Vertical equipment: for large equipment, loading and unloading holes. Manhole to face the road maintenance side.

Buried pipes

  • (1) circulating hot and cold water. Fresh water. Firewater piping;
  • (2) Oily sewage pipes;
  • (3) Domestic sewage piping.

Environmental protection and occupational safety and health measures

(1) Environmental protection
According to the requirements of SH3024-95 “Design Code for Environmental Protection of Petrochemical Enterprises”, the following measures for environmental protection should be taken in the design.
① Where the start-up and shutdown.

  • In the process of inspection and maintenance, harmful fluid leakage may occur. Diffuse flow of equipment around the area, are set up not less than 150mm high weir and liquid guide facilities.

② Equipment.

Pipeline discharge port, sampling port and overflow port of the discharge should enter the centralized collection system. The setting of the exhaust pipe of the sewage water seal well should meet the requirements of Article 6.1.8 of GB50160-92 (1999 Revised Edition) of the Design Fire Code for Petrochemical Enterprises. The venting port of pressure gas is equipped with muffler, and the directionality of the noise of the venting port is also considered.
(2) Safety and health aspects
Device (unit) layout in addition to meet the fire. Explosion-proof specifications required equipment, buildings and adjacent devices (units) between the safety spacing requirements, but also according to the “Occupational Safety and Health Design Code for Petrochemical Enterprises” SH3047-93 requirements, take the following favorable safety and health measures:

  • ① Vertical equipment platform and multi-layer framework of each layer (or compartment) with a semi-fixed fire-extinguishing steam joints, equipment areas and operating temperatures above the media spontaneous combustion point near the equipment is also equipped with semi-fixed fire-extinguishing steam joints, pipe bridges with utility hose stations under the bridge, all of these joints are arranged in the obvious valve. Safe and easy to operate location.
  • ② Device (unit) surrounded by a fire hose network, class A gas compressor and other equipment that requires key protection near the box fire hydrant; higher than 15m frame platform, with a fire hose, class A equipment on both sides with fire water cannons.
  • ③ Install electrostatic grounding facilities for combustible gas, liquefied hydrocarbon and combustible liquid pipelines in and out of the device (unit).

The pipeline with surface temperature over 60℃ is set up with anti-scald insulation layer within 2.1m height and 0.75m surrounding from the ground or platform surface.
Consider setting up eye washers, drenchers and other safety protection measures in toxic hazards and chemical burn hazards operation areas.

Piping layout design requirements

1. General requirements for pipeline layout
(1) Pipeline grade demarcation.

Due to the design temperature and pressure and the nature of the medium change caused by the piping system pipe grade or pipe material changes, pipe grade demarcation is used to express the location of this change interface.
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Figure 2.2.1
A.B.C three cases usually have the same material but different pipe grade, the flange at the demarcation point. In case D, the material is usually changed, the pressure level of the flange is chosen according to the high level, and the flange, fasteners and gaskets are chosen according to the low level. Fasteners and gaskets of the material according to the low grade selection.
(2) Pipeline blowing
Pipeline blowing is fixed and semi-fixed in two ways, generally expressed in the P&ID. When the P&ID is not indicated, the following provisions should be met.
① General process pipeline of fixed blowing takeover as shown in Figure 2.2.2-1.
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Figure 2.2.2-1
② Semi-fixed purge pipe depending on the media. Toxic. Liquefied hydrocarbons use double valves such as Figure 2.2.2-2A.C, general media with a single valve such as Figure 2.2.2-2B.D.
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Figure 2.2.2-2
(3) Drainage and air release
Process needs of the pipeline discharge and bleeding should be installed in accordance with the requirements of the P&ID, but the pipeline arrangement of unavoidable liquid bags and gas bags, should be set up in accordance with the following requirements of the liquid discharge port and bleeding port. The long BOSS are according to L=120mm.
① Venting
The high point of the pipeline without hydraulic test and the process and utility pipeline with nominal diameter DN≤40 can not set the venting port, and the high point of the rest of the pipeline need to set the venting. The basic form of emptying see Figure 2.2.3-1.
② Discharge liquid
All the low points of the pipeline should be set to drain, the basic form of drainage see Figure 2.2.3-2. raw oil, oil slurry and other high-viscosity media drainage pipeline nominal diameter shall not be less than DN25, the rest of the drainage pipeline nominal diameter shall not be less than DN20.
Equipment body about the instrument discharge should be led to the corresponding discharge funnel; in addition to purified air and non-purified air pipeline, the ground pump. Valve group discharge pipeline (including the upper part of the riser valve discharge) should be led to the nearby side ditch; the pipeline discharge pipeline of the valve group on the frame (including the upper part of the riser valve discharge) should be led to the corresponding discharge hopper, and the total discharge pipe should be led to the frame ground side ditch.
③ Process and utility pipelines, especially high-temperature and high-pressure pipelines on the venting valve can be replaced by blind flange.
General process pipeline discharge. Set up a valve at the venting port. Liquefied hydrocarbons. Toxic media pipelines and high-pressure pipelines are equipped with double valves, or a valve plus blind. High point gas release, low point liquid discharge installation location should be in the downstream of the material flow direction. The pipe section connected with the main pipe should be the smallest.
(4) Slope of the pipe
Overhead flare mains and buried gravity flow pipelines (such as oily sewage pipelines. Oil sludge pipeline) should be sloped to the torch tank or dirty oil (water) recovery facilities, the slope requirements should meet the following requirements:

  • ① fire moment pipeline: the slope of 1-3/1000
  • ② buried pipeline: the minimum slope of 3/1000
  • ③ other P&ID drawings on the special requirements of the pipeline according to the requirements of the P&ID drawings design (such as: steam package return pipeline)

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(5) Pipeline spacing

  • ①The minimum spacing of pipelines laid side by side is 50mm after considering the thickness of heat insulation layer. When there is a flange installed on the pipeline, the minimum headroom between the outer edge of the flange and the adjacent pipe is 25mm.
  • ② Minimum spacing of valve handwheel: DN≥80Min100; DN≤50Min50.
  • ③The minimum headroom from the edge of the open hole when the pipeline crosses the platform is taken as 25mm, and the waterproof ring is set at the edge of the open hole.
  • ④ When calculating the pipeline spacing must consider the pipe displacement and its direction.

(6) Pipeline net height and burial depth

  • ① The net height of the bottom of the pipeline at the passage of personnel should not be less than 2.1m, the need to pass vehicles, the net height of the bottom of the pipe depending on the type of vehicle, the passage of small maintenance machinery or vehicles should not be less than 3.0m, the passage of large maintenance machinery or vehicles should not be less than 4.5m.
  • ② Buried pipeline depth, the general area for the top of the pipe from the surface of not less than 0.3m, under the passage of mechanical vehicles, not less than 0.75m or the use of casing protection, the top of the casing from the surface of not less than 0.3m. The diameter of the casing should be larger than the protected pipe two. Protected pipe in the casing range should not be welded. Buried pipelines with valves should be set up valve wells. Large valve wells should consider the operation and maintenance personnel can go to the well operation. Small valve well can only consider the possibility of personnel operating the valve outside the valve well.
  • ③ When laying with pipe trench, the trench should have a low slope of not less than 2%. Pre-embedded steel bracket in the pipe trench, the top of the bracket is not less than 0.2m from the bottom of the trench, for the bottom of the pipe with drainage valve, the headroom between the trench and the bottom of the pipe should be able to meet the installation and operation of the drainage valve. The pipe with heat insulation layer in the trench should be equipped with pipe bracket. The pipe spacing in the trench should be increased appropriately than the overhead pipe.

(7) The arrangement of the sampling pipe
Sampling tube is used to take out the fluid in the tube for analysis, the form of sampling should be in line with the requirements of P & ID, sampling points should be set up in a convenient place for easy access and convenient operation. Sampling tube should be as short as possible, and not lead from the dead zone on the pipe to reduce fluid stagnation in the tube. In-situ sampling of the first valve grade with the main, after the valve becomes stainless steel.
① Sampling tube on the gas pipeline lead out
For the sampling port on the gas pipeline, when set on the horizontal pipe should be at the top of the pipe, when set on the riser, the sampling port should be inclined upward 45 °; the sampling port on the gas pipeline containing solid particles should be located on the riser, and the sampling tube deep into the center of the pipe.
② The sampling tube on the liquid pipeline lead out
For the sampling port on the liquid pipeline, pressure conveying horizontal pipeline can be set in any part, self-flow horizontal pipeline should be set at the bottom of the pipe, the liquid contains solid particles should be set in the side of the pipe; when set on the standpipe should be located in the upward flow of the medium on the pipe section.
③ Sampling pipe cut-off valve and sampling valve installation position

  • a. sampling pipe cut-off valve from the point of introduction more than 3m, should be installed in the nearest place from the point of introduction root valve, the length of this pipe shall not be greater than 8m.
  • b. sample outlet end of the pipe and funnel ground or platform should have at least 300mm of headroom between to place the sampling vessels.

④ The basic form of the sampling pipeline arrangement is shown in the typical diagram (design manual and the above technical provisions of the relevant articles).
(8) Installation of instrument components
Control valves, volumetric flow meters, etc., should be set up in the operation of convenient, easy to maintain the ground or platform; when the temperature gauge on the pipeline, the location of the pressure gauge can be freely selected, in principle, the height from the operating surface is not more than 1.5 meters. Installed in a variety of instruments on the equipment (such as thermometers, manometers, liquid level meters, etc.) must be set up to operate the platform or ladder.
Installation of control valve
Control valve should be installed as close as possible to its related indicator instruments and as close as possible to the measurement components near the nominal diameter of the control valve is less than the diameter of the pipe, the size of the head should be installed close to the control valve; control valve with a manual device, should confirm the space above or lateral to the membrane head, the installation position of the control valve should make the manual device easy to operate. Angle regulating valve needs to be determined according to the direction of media flow (there are two types of up-in and down-out and down-in and up-out) in the form of angle valve, and set in a place without obstacles. For the regulating valve with high differential pressure, consideration should be given to prevent noise and vibration.

② Flowmeter instrument
Differential pressure flowmeter orifice plate can be located either on the horizontal pipe or on the riser (recommended to be installed on the horizontal pipe), need to be decided according to the media situation. Differential pressure flowmeter orifice plate and volume flowmeter rotor, the length of its upstream and downstream straight pipe should meet the requirements of the self-control professional. Differential pressure flowmeter pressure-taking direction, for steam. For liquids to use the horizontal pressure-taking mode. And the gas is used to take the pressure above the way. Horizontal pressure-taking is limited; such as steam can be used upward-sloping type, such as liquid available downward-sloping type.
③ Pressure gauge
In order to accurately measure the static pressure, the pressure gauge pressure point should be in the straight section of the pipe, set up an extension BOSS + shut-off valve on the pressure pipe, no pressure gauge nozzle, the pressure point should be set in the location of easy to read the meter. When installing the pressure gauge on the vibration pipeline, should avoid vibration to the pressure gauge so that it is damaged, should take appropriate measures to strengthen.
④ Installation of temperature instruments
Installed in the pipeline thermometer, should be expanded according to the requirements of the self-control professional. Thermometer can also be tilted 45 ° horizontal installation, tilted 45 ° installation, should be contacted with the direction of fluid flow in the pipe in the opposite direction. The length of the thermocouple, depending on the diameter of the pipe and the installation location, its location should be located in the easy to insert / pull out the thermocouple. Temperature instrumentation installation methods are described in the design manual, book 1 P399 and the above technical provisions of the relevant provisions.
⑤ Installation of liquid level instrumentation
In order to enable the level meter to be removed in the case of equipment operation, it is necessary to find a way to lan between the shut-off valve and the liquid level meter. Glass plate liquid level meter (there are reflective and translucent type two) and glass tube liquid level meter in the appearance of a big difference. The former is used for high temperature and high pressure, the latter is only used for low pressure. The translucent glass plate liquid level meter should be installed in the direction through which light can pass.
(10) The installation of the safety valve
Safety valve should be installed as close as possible to the protected equipment or the main. In order to prevent vibration when the safety valve is emptying, the pipeline with the safety valve is installed with additional support. If the safety valve can not be set close to the protected equipment or the main, in order to prevent pressure drop, the diameter of the inlet pipe of the safety valve needs to be accounted for. Safety valve inlet piping system should be arranged to enable the liquid in the pipe to flow to the protected equipment or the form of the main pipeline. Safety valve outlet pipe and the venting main pipe connection, in order to make the medium in the pipe self-flow into the main pipe, should follow the main pipe medium flow direction and the main pipe is 45 ° upper access. When the safety valve is released into the atmosphere, if the venting end is higher than the safety valve, a tear hole of Φ6mm should be set in the lowermost part of the outlet pipe. The main pipe of pressure relief and venting should be arranged so that it can enter the liquid distribution tank or condensate tank by itself.
(11) The setting of funnel and floor drain
In order to prevent danger, pollution or recycling, the oil from the equipment, piping system. Water and chemicals, etc., should enter their respective funnels and go to the treatment system via buried pipes. The discharge pipe to the hopper is arranged according to the requirements of P&ID diagram; the floor of the plant, concrete platform, equipment cofferdam, ditch (pit) bottom, etc. are set up to collect the dirt for centralized treatment. The funnel is higher than the ground or platform surface, with castor plate or sieve plate inside to prevent external foreign matter from falling in and causing blockage; the floor drain is slightly lower than the ground or platform surface and the bottom of the ditch (pit), with liquid seal and castor plate to prevent cascading gas and blockage. Among them, for toxic and volatile chemicals should use closed funnels. When deciding the location of the funnel, the following factors should be fully considered.

  • ① Funnels for equipment discharge should be as close to the foundation as possible.
  • ② The arrangement of the funnel should make the drainage pipe to the funnel as short as possible.
  • ③ arrangement of the funnel, the drainage pipe leading to the funnel should not obstruct the nearby traffic and do not affect the operation of the surrounding valves and instruments.
  • ④The setting of the funnel should be as little as possible without affecting the discharge of liquid.
  • ⑤ The equipment body instrumentation and frame should be set up with a funnel to receive the liquid discharge from the sampling tube, etc., and the end of the pipeline for liquid discharge must be connected to the funnel on the ground.

3. Special piping arrangement
(1) Arrangement of two-phase flow pipeline
The same symmetrical arrangement of pipeline pressure drop should be used to achieve the purpose of uniform material distribution in each circuit. In order to ensure the correct measurement and effective control of the liquid in the equilibrium state, the flow measurement elements and control valves on the pipeline should be arranged as close as possible to the equipment outlet to avoid vaporization due to the pressure drop of the pipeline to destroy the equilibrium.
(2) Pressure relief pipeline
Hazardous media equipment pressure relief system should be closed, each relief port are connected to the main discharge torch, and downstream 45 ° slope connected to the top of the main pipe, the main pipe slope to the emergency emptying tank. To may carry easily condensable. Viscous media, should be set up with heat.
(3) Solids transport piping
In order to reduce wear and tear and to facilitate the transport of catalyst, the pipeline design to make the pipeline as short as possible, less bends, must change the direction, are using a radius of curvature ≥ 6D, 9D bends, lifting or blowing with the receiver are used downstream 45 ° oblique connection.
(4) steam turbine main steam piping
Steam turbine inlet and outlet steam piping in addition to meet the equipment manufacturer’s requirements for the inlet and outlet steam receiver nozzle force and torque, the main steam pipeline is also equipped with liquid discharge facilities to prevent condensate from being brought into the turbine to damage the blades. Near the turbine steam inlet nozzle, there is a removable short pipe, as a steam pipe blowing target emptying.
(5) Unit lubricating oil pipeline
To ensure the quality of lubricating oil, all pipes and piping accessories from the filter outlet to each oil supply point of the unit are made of stainless steel. For the convenience of disassembly, the branch pipes are connected with the main oil supply pipe by flange. All oil return pipes are also made of stainless steel, and the connection with the oil return main pipe is flange connection. The return main pipe has a 3% slope in the direction of oil flow. The high oil tank to the oil supply main pipe is as short as possible. Few elbows. No “U” shaped bag.
(6) Heat-insulating and wear-resistant lining pipeline
Catalytic cracking reaction oil and gas piping and flue gas piping (in addition to the inlet piping of the smoke machine) using cold wall or hot and cold wall combination design, cold wall design is the use of heat insulation wear-resistant lining method to achieve.
(7) Heat tracing and hydrophobic
Pipeline tracing heat is generally set according to the process requirements, using steam or hot water tracing heat, centralized steam supply (water). The way of centralized return steam (water), in order to facilitate the operation, inspection and maintenance.
(8) Hose station
Hose station is for cleaning. Blowing and small-scale fire extinguishing is usually configured with fresh water. Steam. Compressed air and nitrogen.

  • ① The order of fluid arrangement from right to left from the direction of operation is: fresh water, steam, non-purge air, nitrogen, the cut-off valve on the pipeline choose gate valve.
  • ② The piping size is DN20.
  • ③ Hose selection: steam pipeline selection of steel wire braided hose; other media selection of cloth hose.
  • ④ Hose joint: steam pipeline HC20-1; compressed air pipeline HC20-2; fresh water pipeline HC20-3.

Piping material design regulations

1. Selection principles
Pipeline equipment is selected according to the requirements of “General Rules for the Selection of Pipeline Design Equipment for Petrochemical Enterprises” (SH3059-2001).
2. The main pipeline equipment standards (specifications) used.
Seamless steel pipe:

  • GB/T8163-1999 “Seamless Steel Pipe for Fluid Transportation
  • GB9948-88 “Seamless Steel Pipe for Petroleum Cracking
  • GB/T14976-94 “Stainless steel seamless steel pipe for fluid transportation
  • GB6479-2000 “Seamless steel pipe for high pressure chemical fertilizer equipment
  • GB5310-1995 “Seamless Steel Pipe for High Pressure Boiler

Welded steel pipe:

  • GB/T3091-2001 “Welded Steel Pipe for Low Pressure Fluid Conveying

Pipe fittings:

  • SH3408-96 “Steel Butt-welded Seamless Pipe Fittings
  • SH3409-96 “Steel Butt Weld Pipe Fittings
  • SH3410-96 “Forged Steel Socket Weld Fittings

Coupling parts:

  • SH3406-96 “Petroleum and Chemical Steel Pipe Flanges
  • SH3401-96 “Asbestos rubber gaskets for pipe flanges
  • SH3403-96 “Metal Gaskets for Pipe Flanges
  • SH3404-96《Fasteners for pipe flanges
  • SH3407-96 “Winding Gaskets for Pipe Flanges

3. Selection of pipe fittings and pipes
(1) Tubes. Pipe fittings

  • ① The pipe size series of this project is selected according to “Size Series of Steel Pipe for Petrochemical Enterprises” (SH3405-96).
  • ② The reaction oil and gas pipeline is a combination of cold wall (20R + heat insulation and wear-resistant lining) + hot wall (15CrMoR) pipeline.
  • ③ The material of flue machine inlet pipe is 316H, the expansion joint bellows on the flue gas pipe is INCONEL625 and INCOLOY800, and the expansion joint bellows on the main air pipe is 304.
  • ④ The pipeline connected with anti-high temperature equipment, the pipeline material between the equipment nozzle and the first cut-off valve is heat-resistant stainless steel or alloy steel.
  • ⑤ DN ≤ 40 of the purification of compressed air pipeline selection Q235B + galvanized GB / T3091.
  • ⑥ Pipe connection except for installation and maintenance must be disassembled are used welding, DN ≥ 50 pipeline using butt welding; DN ≤ 40 pipeline (in addition to the unit lubricating oil. Seal oil pipeline) are connected by socket welding.

(7) In principle, DN32, DN65, DN125, DN175 and other special pipe diameters are not used. When these pipe diameters are used in the interface of machinery and equipment, the piping system is connected with a reducer.
(2) Valves
The valves of this project are selected from the API manufacturing standard series and conform to SH3064-94 “Petroleum and Chemical Steel General Valve Selection. Inspection and acceptance specification” of the product. The valves used in the above-ground part of the project are made of steel. Underground part of the water supply and drainage design technical provisions of the relevant standards selected.
(3) Flange and gasket
The pipe flange is selected from SH3406-96 standard series. The gasket type is mainly wave tooth gasket.
4. Heat insulation materials
(1) Heat insulation materials are selected according to the requirements of Technical Specification for Heat Insulation of Petrochemical Equipment and Pipelines (SH3010-2000).

(2) Heat insulation material of pipeline:

  • ① The medium temperature of pipeline is T≤2500C, DN>350 adopts rock wool coil blanket, DN≤350 adopts rock wool pipe shell.
  • ② Pipe medium temperature 2500C<T≤5500C, using microporous calcium silicate (non-asbestos). Shaped equipment (pump. Valves, etc.) heat insulation materials using composite silicate slurry. Its performance requirements shall conform to the provisions of “Technical Specification for Thermal Insulation of Petrochemical Equipment and Pipelines” (SH3010-2000).
  • ③ Austenitic stainless steel pipeline with heat insulation material chloride ion content shall not exceed the allowable value of “covering austenitic stainless steel with insulation material specification” GB/T17393-1998. Insulation material using polyurethane plastic products, should be flame retardant materials, and its oxygen index should not be less than 30.

5. Anti-corrosion coating
(1) Anti-corrosion materials according to the “petrochemical equipment and pipeline coating anti-corrosion technical specifications” (SH3022-1999) requirements for the selection.
(2) The anti-corrosion material of buried pipeline adopts epoxy coal asphalt + glass cloth, and the anti-corrosion grade is special strengthened grade.
(3) Anticorrosion materials for overhead pipelines.

  • (1) Not insulated pipeline, pipeline medium temperature ≥ 200 ℃ or the need for steam blowing pipeline using inorganic zinc-rich primer + silver powder topcoat; medium temperature <200 ℃ or do not need steam blowing pipeline using iron red epoxy silicone heat-resistant primer + silver powder topcoat.
  • (2) Iron red phenolic antirust primer is used for heat insulation pipelines.

(4) The surface color and mark of the pipeline is according to the “surface color and mark of the equipment pipeline of petrochemical enterprises” (SHJ43-91).
6. Lining materials
(1) Lining materials are selected according to the requirements of “Technical Specification for Heat Resistant and Wear Resistant Concrete Lining” (SH3531-1999).
7. Division of design scope with related professions
(1) Piping connected with the equipment
Towers and other non-standard equipment take over the corresponding flange and fasteners and seals, by the equipment professional pairing, special place to equipment professional commission. General equipment heat exchangers. Machine pumps, etc. and mechanical specialties listed in the equipment mouth corresponding to the flange. Fasteners and seals are matched by the manufacturer.

(2) And instrumentation connected to the pipeline instrumentation with blowback.

Heat and purified air to each partition of the trunk pipe and root valve by the pipeline professional responsible for each partition of the trunk pipe diameter. The number of branch pipes and pipe diameter. The branch pipe openings and valves are the responsibility of the piping department, and are indicated in the drawing to be connected to the instrumentation department. Thermocouple, RTD casing nozzle for temperature measurement is responsible for the design of the pipeline, when the measuring element is connected by flange on the pipeline, the fasteners and seals are listed by the piping profession, and the instruments connected in series in the process pipeline such as regulating valves. Flowmeter, etc., corresponding flange, fasteners. Seals and their bypass piping are the responsibility of the piping professional.

(3) Connection with the plant piping network
Each device (unit) piping design scope, unless otherwise specified, are responsible for the device boundary area (including access to the device raw materials, finished or semi-finished products piping, utility piping, fire water piping, sewage piping), the demarcation point in the device boundary line outside one meter.
(4) and the electrical connection
Each device (unit) pipeline electrostatic grounding pipeline on the connection plate by the pipeline professional responsible for the map.

Pipeline mechanical design

1. Pipeline flexible design
(1) Pipeline flexibility design according to the “petrochemical enterprise pipeline flexibility design specification” (SHJ41-91) and “process piping” (ASME/ANSIB31.3) requirements.
(2) Pipeline stress analysis method

  • ① The designer judge by experience;
  • ② Use the chart to judge.

(3) Detailed analysis by computer.
(3) Stress analysis calculation benchmark and application

  • ① Calculation benchmark ASME/ANSIB31.3SHJ41-91.
  • ② Application CAESARII (only LPEC is required to use).

(4) Determination of calculation parameters
① Calculation temperature
Pipeline flexibility analysis and stress analysis is usually calculated according to the difference between the calculated temperature and the installation state temperature (ambient temperature) under different operating conditions (stress analysis temperature difference), and in accordance with the following provisions:

  • a. The installation state temperature (ambient temperature) is taken as 20℃.
  • b. for general process and utility piping to take the operating temperature of the pipeline in the pipeline table.
  • c. For the steam external heat tracing pipeline to take the higher of the steam tracing temperature minus 10℃ and the operating temperature of the pipeline being heated.
  • d. For the pipeline that needs steam purge, when the operating temperature is lower than the steam temperature, take the purge steam temperature; when the operating temperature is higher than the steam temperature, take the operating temperature of the pipeline.
  • e. For the pipe without insulation, when the medium temperature is lower than 38℃, take the medium temperature; when the medium temperature is higher than 38℃, take 95% of the highest medium temperature.
  • f. With lining or internal insulation of the pipe, the calculated temperature should be determined by calculation or actual measurement.
  • g. Safety relief piping to take the highest or lowest temperature that may occur when discharged.
  • h. Normal temperature piping (-100C to 500C) with 600C temperature difference for stress analysis.
  • I. Compressor inlet piping with external heat tracing is taken as the actual operating temperature +200°C to perform stress analysis.

② Calculated pressure is taken from the design pressure of the pipeline in the pipeline table.
(5) When the pipeline is operated under different operating conditions, different combinations of operating conditions are analyzed, such as start-up and shutdown conditions. Steam blowing condition. Regeneration conditions.
(6) Permissible stress
① Basic allowable stress
The basic allowable stress of the introduced material is according to ASME/ANSIB31.3, and the basic allowable stress of the domestic material grade is according to GB150-1998.
② The evaluation of the allowable stress value according to the requirements of chapter 5 of SHJ41-91.
(7) The nozzle force and moment calibration

  • ① Pump according to the requirements of the manufacturing diagram, if the manufacturing diagram does not have data, then according to the requirements of API610.
  • ② Turbine and compressor according to the requirements of the manufacturing drawings, if there is no data in the manufacturing drawings, then according to the requirements of NEMASM23.

2. Seismic design of non-buried pipeline
According to the requirements of “General Rules for Seismic Design of Non-Buried Pipelines in Petrochemical Enterprises” (SHJ39-91), the following measures are taken in the pipeline design: valves and fittings are made of steel; pipeline connections are welded except for special needs; pipeline compensators are made of non-filling compensators; pipe racks are equipped with measures to prevent lateral slippage of pipelines; pipelines laid along vertical equipment are equipped with guide brackets.

Additional provisions

1. Each device (unit) for the ground load-bearing supported pipe diameter DN ≥ 150 bracket, the pipeline professional entrusted to the civil engineering professional design pipe pier, pipe pier specifications are as follows:

  • Pier-1: 260X260; supported pipe: DN150-250.
  • Pier-2: 350X350; supported pipe: DN300-400.
  • Pier-3:450X450;supported pipe>DN400
  • Equal area steel plate is pre-buried on the pier surface; pier surface elevation: 50mm above the ground level.

2. When the equipment opening is entrusted, the equipment 0 and Jianbei should be consistent.
3. The pipeline in the tank area is arranged in pipe pier type, and the pier is 300mm higher than the local ground level.

Piping design drafting regulations

1. Drawing size. Proportion. Legend and diagrammatic way

  • (1) The drawing width is 0# or 1# standard drawing width.
  • (2) device (unit) layout using a ratio of 1:200; piping layout using a ratio of 1:30 or 1:50; the rest of the diagram may not be proportional.
  • (3) device (unit) layout and piping layout legends are in accordance with the “petrochemical enterprise piping engineering design legend” (SH3052-93) implementation, except for the bracket legend.
  • (4) device (unit) layout using the plane and vertical way of representation; piping layout using the plane plus the detailed way of representation. Detailed requirements are strictly in accordance with the relevant provisions.

2. Drawings marked content regulations:
(1) Pipe number: The pipe number is marked near the pipe or on the lead-in line, and the pipe number is composed of “Nominal diameter of pipe —- Media code — Pipe sequence number — Grade number — Thermal insulation requirement”.

  • a. Pipe nominal diameter: the nominal diameter DN of the pipe, when the DN of the same pipe is changed, the DN number of the main pipe section is generally marked.
  • b. Medium code and pipe sequence number: consistent in process pipeline and instrument flow chart.
  • c. Grade number: according to the use of the pipeline, the pipeline grade number selected in the pipeline grade table.
  • d. Thermal insulation requirement: expressed by “thermal insulation code + thermal insulation thickness”.

(2) The demarcation points on the pipeline: all kinds of demarcation points on the pipeline are marked on the pipe section diagram, and those without the pipe section diagram are marked on the pipe plan and its subsidiary details. Pipeline demarcation points have the following content:

a. Pipeline partition (insulation. Heat tracing. Anti-scalding, etc.) thermal range of the demarcation method as shown in Figure 6.2.2-1.

20211002012858 54157 - How to design pipeline layout

Figure 6.2.2-1

b. Piping material grade demarcation line, such as Figure 6.2.2-2.

20211002012910 40813 - How to design pipeline layout

Figure 6.2.2-2

c. Pipeline factory-made and field installation demarcation line, such as Figure 6.2.2-3, no such demarcation line of the pipeline factory-made and field installation demarcation line are determined by the construction unit.

20211002012933 16533 - How to design pipeline layout

Figure 6.2.2-3

3. Special fittings and special materials:

  • (1) the size of the reducer fittings with “DN (large end nominal diameter or mother pipe diameter) X DN (small end nominal diameter or branch nominal diameter)”.
  • (2) special material code: the use of pipe material grade number inconsistent with the pipe fittings, marked with the special material code of this pipe fittings (which is consistent with the code listed in the materials table).
  • (3) special fittings and small equipment in the pipe section diagram or detailed drawings marked on its model or diagram number, according to its model or diagram number can be found in the text data from the relevant construction drawings of its installation dimensions.

4. Slope of the pipe:

According to a certain slope set of pipeline are painted with slope symbol, the symbol slope down direction that is the direction of decline in the elevation of the pipeline. Slope method:

  • 1) The number i=0.XXX on the slope symbol indicates the slope value of the pipe;
  • 2) the slope of the pipe without the number on the slope symbol is determined by the point with the elevation on the pipe.

5. Safety valve. Control valves. Instrument components and other special valves
For easy identification and installation, the piping layout (plan. Detailed drawings) are marked with the “process piping and instrumentation flow chart” “with control points of the utility piping flow chart” consistent with the bit number.
6. Dimensions. Elevation
(1) Dimensional datum line. Reference point
Pipe and fittings to determine the size of the baseline. Reference point.
(2) Dimensions. Elevation of the general representation requirements

  • ① The dimensions in the drawing. Elevation, except as noted, are expressed in millimeters (mm) as the unit.
  • ② From other marked dimensions. The size of the elevation can be deduced from the standard high. The elevation will not be marked.
  • ③ Additional shims. Hole plate. 8-way blind. The thickness of the blind plate (including both sides of the gasket) will be used.
  • ④ If there is a standard installation drawing, the installation dimensions will not be indicated, such as the installation dimensions of the tracing pipe in parallel with the pipe.
  • ⑤ The same equipment is arranged in sequence. Rotary machinery, when the pipeline arrangement is also the same, will only mark one of the equipment or rotary machinery piping size, other equipment or rotary machinery piping size is omitted.

(6) Vertical equipment shown in a layered drawing. Frame. Pipe bridge and other related pipes. Its positioning dimensions are generally marked in the drawing of the bottom layer of the pipeline layout, and the above plan only note the change in the size of the pipeline.
7. pipe support hanger

  • (1) bracket number: the bracket number on the surface of the diagram is the bracket of one or several related pipeline layout diagrams according to different types of specifications from the beginning of the order, the format is: PS – order number, generally marked on the pipeline layout diagram or subsidiary details.
  • (2) the support hanger table: marked with the bracket code of the drawing generally has the support hanger table column, placed in the upper right corner of the figure.

8. Other diagrams and subsidiary tables
(1) equipment or rotary machinery code. Name where the equipment for A, B number, need to be indicated in the pipe layout A, B respectively.
(2) the diagram needs to draw the instrument location and primary valve installation orientation.
(3) device boundary line and wiring demarcation line.

  • ① The device boundary lines are marked with B.L (BATTERYLIMIT abbreviation) mark;
  • ② The diagram shows the connection demarcation line are marked with ML (MARCHLINE written) mark.

Source: China Piping Solution Provider – Yaang Pipe Industry Co., Limited (

(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)

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