GB 51142-2015Code for design liquefied petroleum gas (LPG) supply engineering (English PDF)

2.0.1 LPG supply station

It has the functions of storage, loading and unloading, filling, gasification, gas mixing, distribution, etc., and is a special place for the purpose of storage and distribution, gasification (gas mixing) or operation of liquefied petroleum gas. It is the general name of liquefied petroleum gas plants and stations. Including storage station, storage and distribution station, filling station, gasification station, gas mixing station, bottle group gasification station and bottled supply station.

2.0.2 LPG stored station

Composed of storage and loading and unloading equipment, it is a special place mainly for storage, and the main function is to distribute liquefied petroleum gas to filling stations, gasification stations and gas mixing stations.

2.0.3 LPG stored and delivered station

Composed of storage, filling and loading and unloading equipment, it is a special place with the main function of storing liquefied petroleum gas and the auxiliary function of liquefied petroleum gas filling.

2.0.4 LPG filling station

It is composed of filling, storage and loading and unloading equipment, and it is a special place with liquefied petroleum gas filling operation as its main function.

2.0.5 LPG vaporizing station

Composed of storage and gasification equipment, the main function is to convert liquid liquefied petroleum gas into gaseous liquefied petroleum gas, and supply gas to users through pipelines.

2.0.6 LPG-air(other fuel gas)mixing station

It is composed of storage, gasification and gas mixing equipment. After converting liquid liquefied petroleum gas into gaseous liquefied petroleum gas, it is mixed with air or other gas in a certain proportion to form a mixed gas. After the pressure is stabilized, the gas is supplied to users through pipelines. place.

2.0.7 Vaporizing station of multiple cylinder installations

Equipped with 2 or more liquefied petroleum gas cylinders, adopt natural or forced gasification method to convert liquid liquefied petroleum gas into gaseous liquefied petroleum gas, and supply gas to users through pipelines after stabilized pressure.

2.0.8 Bottled LPG delivered station

Special place for operating and storing bottled liquefied petroleum gas.

2.0.9 Fully pressurized storage tank

Storage tanks containing liquefied petroleum gas at room temperature are characterized by storage pressure changes with ambient temperature.

2.0.10 Semi-refrigerated storage tank

Storage tanks for liquefied petroleum gas at lower temperatures and lower pressures.

2.0.11 Fully refrigerated storage tank

Storage tanks for liquefied petroleum gas at low temperature and atmospheric pressure.

4.1 General provisions

4.1.1 The line selection of pipelines for transporting liquid liquefied petroleum gas shall meet the following requirements.

1 It shall meet the requirements of urban planning, public safety and pipeline protection along the line, and comprehensively consider geological and meteorological conditions.

2.The area with small terrain undulation and easy transportation and construction management should be selected.

3 Do not pass through areas where people gather, such as residential areas and public buildings, warehouse areas, dangerous goods areas, etc.; do not pass through buildings that have nothing to do with it.

4 Do not pass through water source protection areas, factories, large public places and mineral resource areas, etc.

5.Areas prone to geological hazards should be avoided.

6 Avoid or reduce crossing obstacles and facilities such as rivers, railways, highways and subways.

4.1.2 Liquid liquefied petroleum gas pipelines should be designed according to the combination of permanent loads, variable loads and occasional loads that may occur simultaneously according to the laying form, environment and operating conditions, and should comply with the current national standard "Design of Oil Pipeline Engineering". The relevant provisions of GB 50253.

4.1.3 The grading of areas for laying liquefied petroleum gas pipelines shall meet the following requirements.

1 The area grade of the pipeline shall be divided according to the density of buildings in the area classification unit, and shall meet the following requirements.

1) First-level areas. less than or equal to 12 independent buildings for human habitation;

2) Second-level areas. more than 12 and less than 80 independent buildings for human habitation;

3) Third-level areas. areas with 80 or more independent buildings for human habitation, but not enough for fourth-level areas, industrial areas, pipelines and independent buildings for human habitation, or stadiums and open-air theaters where people gather (theatres)), farmer's markets and other outdoor public places where the distance is less than 90m;

4) Level 4 areas. buildings with 4 or more floors (excluding the number of basement floors) should be common and account for the majority, with frequent traffic and many underground facilities in the central urban area of the city or the central area of the town.

2 Determining the level of the region through which the liquefied petroleum gas pipeline passes should be based on town planning.

3.Within the range of.200m on both sides of the central line of the pipeline, it is arbitrarily divided into 1.6km long, and the boundary line of the classification should be perpendicular to the pipeline, and can include the largest number of independent buildings for human habitation, as the area classification unit. In multi-unit residential buildings, each individual dwelling unit counts as a separate building for human occupancy.

4 The boundary line of the second- and third-level areas should not be less than.200m away from the nearest building in the area of this level.

5 When demarcating the boundary line between the fourth-level area and other-level areas, the nearest building with 4 or more floors above the ground shall not be less than.200m away from the boundary line of the next area level.

4.1.4 The strength design factor of liquid liquefied petroleum gas pipelines shall comply with the requirements in Table 4.1.4.

Table 4.1.4 Strength Design Factors of Liquid LPG Pipelines

4.1.5 The strength design factor of the liquid liquefied petroleum gas pipeline passing through the railway, highway, upstream and downstream of the station shall comply with the provisions in Table 4.1.5.

Table 4.1.5 Strength Design Factors of Liquid LPG Pipelines Crossing Railways, Highways, Upstream and Downstream of Plants and Stations

4.1.6 Pipelines shall not pass under the sites where flammable and explosive materials and corrosive liquids are accumulated, shall not be laid in the same ditch with other pipes or cables, and shall not pass through valve wells, valve chambers, underground culverts, Underground spaces such as trenches.

4.2 Piping design

4.2.1 The material and wall thickness of liquid liquefied petroleum gas pipelines and the selection and calculation of pipeline accessories shall comply with the provisions in Section 9.1 of this code.

4.2.2 Liquid liquefied petroleum gas pipelines shall be classified into 3 grades according to the design pressure (P), and shall comply with the requirements in Table 4.2.2.

Table 4.2.2 Classification of liquid liquefied petroleum gas pipelines

4.2.3 When the liquid liquefied petroleum gas pipeline is equipped with a safety relief device, the set pressure or the maximum calibrated burst pressure shall be less than the design pressure of the pipeline.

4.2.4 During the pipeline transportation of liquid liquefied petroleum gas, the absolute pressure at any point along the way should be higher than the saturated vapor pressure at the transportation temperature. The design pressure of liquid liquefied petroleum gas pipelines should be higher than the maximum working pressure at the beginning of the pipeline system. The maximum working pressure at the starting point of the piping system can be calculated as follows.

In the formula. Pq - the maximum working pressure at the starting point of the piping system (MPa);

H——Select the head of the pump, and convert it into pressure (MPa) when calculating;

Ps——the saturated vapor pressure (absolute pressure, MPa) at the maximum working temperature of the storage tank at the beginning;

Pa——atmospheric pressure (MPa) at the starting point of the piping system (the storage tank at the starting end), which may be taken as 0.1.

4.2.5 When liquid liquefied petroleum gas is transported by pipeline, the head of the pump should be greater than the calculated head of the pump. The calculation head of the pump can be calculated according to the following formula.

In the formula. Hj——the calculation head of the pump (MPa);

deltaPz——The total resistance loss of the pipeline (MPa), preferably (1.05-1.10) times the pipeline friction resistance loss;

deltaPgamma——residual pressure (MPa) at the end of the pipeline entering the tank, preferably (0.2-0.3) MPa;

deltaH——The additional pressure (MPa) caused by the elevation difference between the end point and the start point of the pipeline.

4.2.6 The frictional resistance loss of liquid liquefied petroleum gas pipeline shall be calculated according to the following formula.

In the formula. deltaP——pipeline frictional resistance loss (MPa);

L——the calculated length of the pipeline (m);

u—the average flow velocity of liquid liquefied petroleum gas in the pipeline (m/s);

d - the inner diameter of the pipe (m);

rho—the density of liquid liquefied petroleum gas at the average delivery temperature (kg/m3);

lambda——Frictional resistance coefficient of pipeline;

K——The equivalent absolute roughness of the inner surface of the pipe wall (m);

Re - Reynolds number.

4.2.7 The average flow velocity of liquid liquefied petroleum gas in the pipeline shall be determined after technical and economic comparison. The average temperature of the cold month.

4.2.8 The connection of liquid liquefied petroleum gas pipelines shall be welded; the pipelines and equipment, valves, etc. may be flanged or threaded.

4.2.9 The welding between liquid liquefied petroleum gas pipelines and between pipelines and pipeline accessories shall comply with the provisions of Section 9.2 of this code.

4.2.10 Natural compensation or Pi-shaped compensator should be used for liquid liquefied petroleum gas pipelines, and packing type compensators should not be used.

4.2.11 When the buried liquefied petroleum gas pipeline is laid elastically, it shall comply with the relevant provisions of the current national standard "Code for Design of Oil Pipeline Engineering" GB 50253.

4.2.12 Liquid liquefied petroleum gas pipelines should be combined with external anti-corrosion coating and cathodic protection, and should meet the requirements of Section 9.4 of this code.

4.2.13 The setting of valves for liquid liquefied petroleum gas pipelines shall meet the following requirements.

1 Special valves should be used, and their performance should meet the relevant provisions of the current national standards;

2 The valve should be set according to the length of the pipe section, the importance of the location of the pipe section and the need for maintenance, and should consider factors such as the ability to cut off the accident pipe section in time when an accident occurs;

3 Valves should be installed at the starting point, end point and branch point of the pipeline;

4.Valves should be installed on both sides of liquefied petroleum gas pipelines that cross railways, highways, expressways, urban expressways, large rivers, and ground laying; segmental valves should be installed at intervals of 5000m along the pipeline, and the valves should have remote control functions;

5 The valves in the pipe section using pigs or electronic pipe detectors should use full-bore valves.

4.2.14 A relief valve shall be installed between the valves of the pipeline section. A pipeline safety valve shall be installed between the two valves of the pipeline laid on the ground, and a valve shall be installed between the pipeline safety valve and the pipeline. The height of the discharge pipe mouth of the safety valve and relief valve from the ground shall not be less than 2.5m. The set pressure of the pipeline safety valve shall comply with the relevant provisions of the current national standard "Pressure Vessel" GB 150.1~GB 150.4.

4.2.15 The valves of LPG pipelines should not be installed in underground valve wells.

4.3 Pipe laying

4.3.1 Liquid liquefied petroleum gas pipelines should be laid underground; when conditions are limited, they can be laid on the ground and temperature compensation should be considered.

4.3.2 Liquid liquefied petroleum gas pipelines shall not be laid under the surface of urban roads, highways and expressways (except for crossing pipelines). The burial depth of the pipeline shall be comprehensively determined according to the depth of frozen soil, ground load, terrain and geological conditions, groundwater depth, pipeline stability requirements and the level of the pipeline passing through the section where the pipeline passes. The minimum soil covering depth for pipeline embedding shall meet the following requirements.

1 It should be buried below the soil freezing line;

2 When buried in the section where motor vehicles pass by, it shall not be less than 1.2m;

3 When buried in a section where motor vehicles cannot reach, it shall not be less than 0.8m;

4 When the above requirements cannot be met, effective safety protection measures should be taken.

4.3.3 Permanent signs such as mileage stakes, corner stakes, cross stakes and warning signs shall be set along the buried pipeline, and shall comply with the relevant provisions of the current national standards.

4.3.4 When buried pipelines cross railways and highways, in addition to complying with the relevant provisions of the current national standards, the following provisions should also be complied with.

1 Pipelines should cross railways and highways vertically.

2 Pipelines crossing railways, expressways and Class I and Class II roads should be laid in casings or culverts. When directional drilling is used for traversing, technical demonstration shall be carried out, and no casing may be added under the premise of ensuring the safe operation of railways and highways.

3 When crossing tram tracks or main arterial roads in cities and towns, pipelines should be laid in casings or pipe trenches, and the pipe trenches should be filled with neutral sand.

4 When crossing the roads of grade III and below, the pipeline can be buried by open cut.

4.3.5 The laying of casing shall comply with the following regulations.

1 Steel pipes or reinforced concrete pipes should be used.

2 The inner diameter of the casing should be 100mm larger than the outer diameter of the liquid liquefied petroleum gas pipeline.

3 The gap between the two ends of the casing and the liquid liquefied petroleum gas pipeline shall be sealed with flexible anti-corrosion, waterproof and insulating materials. A leak detection pipe should be installed at one end of the casing or pipe trench, and the leak detection pipe should lead out to the ground, and the height of the pipe mouth from the ground should not be less than 2.5m. When the casing is filled with fine soil and fine sand, leak detection pipes and tight seals at both ends may not be provided.

4 The distance between the casing end and the embankment slope angle of the railway line shall not be less than 2.0m; the distance between the end of the casing and the edge of the expressway and the road shall not be less than 1.0m.

4.3.6 The clear distance between flanges and valves of buried liquid liquefied petroleum gas pipelines and wells such as sewage, rainwater and cables shall not be less than 5.0m.

4.3.7 When liquefied petroleum gas pipelines intersect with gravity flow pipelines, ditches, culverts,, etc., casings shall be installed at the intersections, or other effective protective measures shall be taken.

4.3.8 The horizontal clear distance between buried liquefied petroleum gas pipelines and buildings or adjacent pipelines should not be less than the provisions in Table 4.3.8-1; the vertical clear distance between buried pipelines and adjacent pipelines or roads It should not be less than the stipulations in Table 4.3.8-2.

Table 4.3.8-1 Horizontal clear distance between buried liquid liquefied petroleum gas pipelines and buildings or adjacent pipelines

Note. 1.The horizontal clear distance of special buildings shall be based on the demarcated boundary line;

2 Residential areas refer to areas with 1,000 people or more than 300 households. Areas with 1,000 people or less than 300 households are subject to other civil buildings in this table;

3 The horizontal clear distance between the liquid liquefied petroleum gas pipeline laid on the ground and the building shall be doubled according to the provisions in this table.

Table 4.3.8-2 Vertical clear distance between buried liquid liquefied petroleum gas pipeline and adjacent pipeline or road

Note. When there is a casing, the calculation of the vertical clearance should be based on the outer wall of the casing.

4.3.9 When crossing through excavation construction, the vertical clear distance between buried pipelines and railways and trams may be appropriately reduced, and shall not be less than 1.2m.

4.3.10 The horizontal clear distance between the buried liquid liquefied petroleum gas pipeline and the grounding body of the AC power line shall not be less than the provisions in Table 4.3.10.

Table 4.3.10 Horizontal clear distance between buried liquid liquefied petroleum gas pipeline and grounding body of AC power line

5.1 General provisions

5.1.1 The site selection of liquefied petroleum gas storage stations, storage and distribution stations and filling stations shall meet the requirements of the overall urban planning and the special urban gas planning.

5.1.2 The site selection of liquefied petroleum gas storage station, storage and distribution station and filling station shall meet the following requirements.

1 Level 3 and above LPG storage stations, storage and distribution stations and filling stations should be set up on the edge of towns or in relatively independent safe areas, and should be far away from residential areas, schools, theaters, gymnasiums and other places where people gather;

2 The liquefied petroleum gas storage station, storage and distribution station and filling station built in the central urban area and densely populated areas of the city shall comply with the provisions of Chapter 3 of this code;

3 The terrain should be flat, open and not easy to accumulate liquefied petroleum gas, and should avoid geological disaster-prone areas;

4 It shall have the conditions of transportation, power supply, water supply and drainage and communication;

5.It is advisable to choose the upwind side of the annual minimum frequency wind direction in the area.

5.2 Floor plan

5.2.1 The general layout of the liquefied petroleum gas storage station, storage and distribution station and filling station shall be divided into production areas (including storage tank areas and filling areas) and auxiliary areas. The production area should be arranged on the upwind side or upper sidewind side of the annual minimum frequency wind direction in the station area.

5.2.2 The boundaries of liquefied petroleum gas storage stations, storage and distribution stations and filling stations should be set up with walls. Non-combustible solid fences with a height of not less than 2m should be set up in the production area, and non-combustible non-solid fences can be set up in the auxiliary area.

5.2.3 Liquefied petroleum gas storage station, storage and distribution station and filling station...