What is LPG pipeline?

2018-12-15

What is LPG pipeline?

The LPG pipeline （liquefied petroleum gas pipeline） refers to the main pipeline that transports liquefied petroleum gas. Liquefied petroleum gas refers to a mixture of hydrocarbons such as liquid propane, butane, propylene, butylene, and the like. The boiling temperature of propane at normal pressure (101,325 Pa) was _42 t, and butane was 0.5 °C. It is usually pressurized to 0.7 MPa or more at normal temperature or frozen to below minus 42 ° C under normal pressure, and transported by pipeline or canned or shipped.

Liquefied petroleum gas must take measures to prevent vaporization during pipeline transportation.

For example:

The pressure at each point along the pipeline must be greater than the saturation pressure of the liquefied gas at the delivery temperature.
The liquefied gas pipeline should have a good insulation layer to prevent the surrounding medium from transferring heat to the liquefied gas in the pipeline.
The pressure drop and temperature rise during the transportation of liquefied gas may cause the liquefied gas to vaporize. If necessary, an intermediate cooling station should be provided to provide cooling capacity for the liquefied gas.
The pumping station pressure should be about 9.8X105Pa higher than the saturated steam pressure at the liquefied gas inlet temperature to prevent the pumping of the pumping air.
When the pipeline is stopped, the pressure inside the pipeline will increase due to the heat transfer from the surrounding medium. The safety valve connected to the venting tank should be installed at the inlet and outlet to make the pipeline pressure not exceed the allowable value.

What is liquefied petroleum gas?

Liquefied petroleum gas (LPG) is one of the petroleum products. It is a colorless and volatile gas obtained from the pressure, cooling and liquefaction of refinery gas or natural gas (including oilfield associated gas). The liquefied petroleum gas obtained from refinery gas, the main components are propane, propylene, butane, butene, and contains a small amount of pentane, pentene and trace sulfur compound impurities. The composition of the liquefied gas obtained from natural gas is substantially free of olefins.

Image from www.elgas.com.au

1, Shape, situation
The main quality control indicators for LPG are evaporation residues and sulfur content, and sometimes olefin content. It is a kind of flammable substance. When the content in the air reaches a certain concentration range, it will explode when exposed to an open flame.
LPG is mainly composed of propane and butane, and some LPGs contain propylene and butene. Compared with other fuels, it has the following advantages:
1 less pollution. LPG is a hydrocarbon composed of carbon three and carbon four, which can be completely burned without dust. Application in modern cities can greatly reduce the pollution caused by coal and diesel fuel in the past.
2 heat is high. The same weight LPG has a calorific value equivalent to twice that of coal and a liquid calorific value of 45 185 to 45 980 kJ/M3.
3 easy to transport. LPG is a gas at normal temperature and pressure. It can be liquefied into liquid under a certain pressure or frozen to a certain temperature. It can be transported on land and water by train (or car) tanker and LPG ship.
4 pressure is stable. The pressure of the LPG pipe user before the stove is unchanged, and the user is convenient to use.
5 The storage device is simple and the supply mode is flexible. Compared with the production, storage and supply of city gas, LPG’s storage equipment is relatively simple. The gas station is stored in LPG storage tanks, and can be installed in gas cylinders for users to use, or through gas distribution stations and supply pipe networks. Pipeline gas supply is implemented.
Therefore, LPG is widely used as an industrial, commercial, and civil fuel. At the same time, its chemical composition determines that LPG is also a very useful chemical raw material, and is therefore widely used in the production of various chemical products.
2, Processing technology
Liquefied petroleum gas is a by-product of the refinery’s catalytic cracking and thermal cracking. The main components of the catalytic cracking gas are as follows (%): methane 10, ethane 3-5, ethylene 3, propane 16-20, propylene 6-11, butane 42-46, butene 5-6, containing 5 carbon atoms The above hydrocarbons 5-12. The main components of the pyrolysis gas are as follows (%): methane 5-7, ethane 5-7, ethylene 16-8, propane 0.5, propylene 7-8, butane 0.2, butene 4-5, containing 5 carbon atoms The above hydrocarbons 2 to 3. These hydrocarbons are easily liquefied, compressed to only 1/250-l/33 of the original volume, stored in high pressure resistant steel tanks, used to unscrew valves of liquefied gas tanks, flammable hydrocarbons The gas enters the burner through the pipe. After ignition, a light blue flame is formed, and a large amount of heat is generated during the combustion process.
3. Use of liquefied gas
With the development of the petrochemical industry, liquefied petroleum gas (LPG) has become more and more important as a basic chemical raw material and a new type of fuel. In terms of chemical production, liquefied petroleum gas is separated to obtain ethylene, propylene, butene, butadiene, etc., which are used to produce synthetic resins, synthetic rubber, synthetic fibers and produce medicines, explosives, dyes and other products. Because of its high calorific value, smokeless dust, and no carbon residue, it is easy to operate and use. Liquefied petroleum gas has been widely used in people’s daily life, such as civil fuel. In addition, liquefied petroleum gas is also used for metal cutting, baking of agricultural products, and roasting of industrial furnaces.
1) For non-ferrous metal smelting
In the non-ferrous metal smelting, the fuel calorific value is required to be stable, the non-burning furnace product is not polluted, and the liquefied petroleum gas has these conditions. After the liquefied petroleum gas is heated and gasified, it can be conveniently introduced into the smelting furnace for combustion, instead of the original gas combustion process, reducing the harm of impurities such as sulfur and phosphorus.
2) Kiln roasting
The relevant state departments have proposed that China’s energy future development tasks are: optimizing the energy structure, establishing a world-class clean, safe and efficient energy supply system, and establishing an energy technology development promotion mechanism. To meet this requirement, many industrial furnaces and furnaces have switched to liquefied petroleum gas as fuel. For example, ceramic tile, baking and rolling sheet, etc., have been converted to liquefied petroleum gas as fuel, which not only reduces the pollution of the air, but also greatly improves the quality of the product.
3) Doing car fuel
At present, about 70% of urban air pollution sources are from automobile emissions. In order to solve this problem, since the end of the 20th century, China’s large and medium-sized cities have successively built automobile refueling stations, using liquefied petroleum gas instead of gasoline as automobile fuel. This change in fuel varieties has greatly purified urban air quality. Another development direction of the utilization of liquefied petroleum gas.
4) Residential life burning
The liquefied petroleum gas used in the residential life is supplied in a bottle, and the bottled gas is connected to the stove in a household by a hose, which is convenient to use.

Materials of LPG pipeline

(Liquefied petroleum gas）LPG pipelines are typically made from galvanized steel for interior work, or from black steel pipe for underground. Last-leg fittings and tubes which connect the stub-outs to various appliances are sometimes made from copper and brass.

ASTM A106, A53GRB, A53-A, A106-A, A192, A226, A315-B, A106-B, A178-C, A210-A-1, A210-C, A333-1.6, A334-1.6, A333-7.9, A334-7.9, 150M19, En46..
API 5L X42, X52, X60, X65, X70
Standards
ANSI B16.9 / 16.28, ASTM A53/A106, API 5L, ASME B36.10M—1996, DIN2605 / 2615 / 2616, JIS P2311/2312
Wall thickness
SGP, STD, SCH40, SCH80, SCH160. XS, XXS and so on.
Length: 6-12m
Industrial process
hot rolled, hot expanded, cold drawn, and hot galvanized
Surface treatment
Transparent oil, rust-proof black oil or hot galvanized

Some things to consider:
When joining two pipes made from dissimilar metals (including steel and cast iron), always use a dielectric union to decrease the risk of galvanic corrosion between the two metals.
In US jurisdictions, exterior pipes must be painted to reduce the risk and rate of weathering.
The additive has a foul smell which causes leaks readily detectible by most people. The compounds contain sulfur and will react with copper to form copper sulfide, eventually corroding through the Pipes. Some copper pipes of types K and L are approved for use with gas. Only properly approved copper pipes should be used with natural gas, with appropriate fittings.
For argon, the first point is still relevant, although the last is likely irrelevant if the argon is pure. The second point may be relevant if you need any pipe runs outdoors.
As for leaking, the pipes themselves should not leak, typically it is joints that leak. If you need high pressure, ensure that the schedule of your pipe is high (ie wall thickness) and that it is rated for the required pressure. As With all pressure vessels, ensure you have appropriate mechanical safety valves and a pressure regulator to decrease the risk of explosion. If you are worried about diffusion through the pipe, unless you plan to heat the argon to many hundreds of degrees C (which you will Need specialized pipe for), the diffusion rates will probably be trivial. Focus on the pipe joints first for leak reduction.
If you only need to transport small quantities of argon over short distances, as in a lab setting, copper and brass flare fittings are most likely sufficient if the pressures aren’t too high. If you need to transport large quantities, you should consult an Professional engineer.

Tensile test and hardness test on LPG pipeline
Hardness test on liquefied petroleum gas pipeline take into account its mechanical properties, this is related to the performance and quality of the LPG pipe as raw material deformation, stamping, cutting and other processing. Therefore, all of the LPG pipeline need to do mechanical testing. Mechanical test methods are mainly divided into two categories, one is the tensile test, another is hardness test.
Tensile test of LPG pipeline made from sample to sample on a tensile tester pull to break, and then determination of one or more mechanical properties, usually only the determination of tensile strength, yield strength, and elongation after fracture and cross-section shrinkage. The tensile test is the basic mechanical properties of LPG pipe material test methods, almost all of the LPG pipe materials, as long as the mechanical properties required by provisions of the tensile test. Especially those that shape is not easy to for LPG pipe material hardness test, tensile test to be the only means of mechanical properties testing.
The hardness test is a rigid indenter according to a predetermined condition slowly pressed into the surface of the sample, and then test the indentation depth or size, in order to determine the size of the material hardness. Hardness test is the LPG pipe mechanical testing easiest, fastest and most easy to implement. Hardness test is non-destructive, Petroleum Steel Pipe hardness values and tensile strength values approximate translation. The hardness value of the LPG pipe can be converted into a tensile strength values, it has great practical significance.
Since the tensile test is not easy to test, and it is very convenient to do the strength and hardness conversion, so more and more people are less liquefied petroleum gas pipeline hardness testing only to test its strength. Especially because of the hardness manufacturing technology continues to progress and innovation, some of the original can not directly test the hardness of the material, such as seamless steel pipe, stainless steel plate and liquefied petroleum gas pipeline, now have may directly test the hardness. Therefore, there is a hardness test gradually replaced by the trend of the tensile test.

（Liquefied Petroleum Gas） LPG Pipeline Sizing

Most people think that any liquefied petroleum gas pipe can be used for gas. This certainly isn’t the case. The size of the pipe dictates the amount of gas that can pass along the pipe. It’s also worth noting that the longer the pipe, the lower the flow (be aware that the flow of gas is measured in BTUs (British Thermal Units) per hour. If you’re going to be working with liquefied petroleum gas it’s important to be familiar with the sizes of liquefied petroleum gas pipes and the amount of gas that can pass along them for different lengths.

Seamless Pipe: 1/2”~24”, DN15~DN600, OD21.3MM~609.6MM, WT: 1-60mm
LSAW pipe: 1/2″-48″, DN15-DN1200, OD21.3-1219.2MM, WT: 1-60mm
SSAW pipe: 1/2″-48″, DN200-DN3600, OD: 219.1-3657.6mm, WT: 6-36mm

Nominal Size
The nominal size of the liquefied petroleum gas pipe is actually the exterior size. This is generally used as a reference for the pipe, although the interior size of the pipe is less. For instance, pipe with a nominal size of one inch will have an interior size of just under ½ inch (actually .49 inches).
Pipe Length
The length of the pipe will have a deep influence on the amount of gas that can flow through it. Where a pipe has a nominal size of one inch, the flow will be 547 BTUs for a 10 foot length of pipe, but only 100 for a 300 foot length of pipe. When making your calculations these need to be taken into account. The longer the run of your pipe, the lower the flow of your liquefied petroleum gas.
Size
Most liquefied petroleum gas pipes run up to a nominal size of four inches, although you can get pip that’s up to eight inches in diameter. When you see the flow for liquefied petroleum gas in pipes, these don’t refer to copper pipes. The specification for these is going to be different, with different figures.
Obviously, the greater the nominal size of liquefied petroleum gas pipes, the greater the gas flow through the pipes. With an 8-inch pipe you’ll have 141,832 BTUs in a 10-foot pipe. For a 150-foot pipe that will be reduced to 36,621. That’s much less, but a great deal more than you’ll find in a pipe with smaller dimensions.
Different sized pipes have different functions. Smaller pipes carry the liquefied petroleum gas to the appliances, for example, and will almost invariably be short runs of pipe. To run a gas cooker, for instance, you need to have good pressure.

Analysis of the Five Advantages of Oil and Gas Pipeline Transportation

Pipeline transportation uses pipeline as a carrier, and pressurizes oil and natural gas with pressurized equipment to flow from high pressure to low pressure and transport it to the destination. It has the following advantages: low transportation cost, small land occupation, fast construction, Large oil and gas transportation capacity, high safety performance, low transportation loss, no “three wastes” emissions, low risk of leakage, low environmental pollution, small impact on bad weather, small equipment maintenance, easy management, easy remote centralized monitoring, etc. . details as follows:
1. Low transportation costs. Among various oil and gas transportation modes, oil pipeline transportation has obvious economical advantages. The carriers of oil and gas for road, rail and water transportation are tank trucks and oil tankers. These modes of transportation consume some of the energy in the movement of the carrier, and require empty vehicles and empty ships to return without continuous transportation. The carrier of the pipeline transportation is the management itself. The oil pump and the compressor directly push the oil and gas to flow around the clock, and it is easy to realize automatic operation, and there are fewer operators. The oil transportation cost of a large tanker that sails only far is lower than that of a pipeline, but it is subject to the constraints of the natural environment and human factors.
2. Small land occupation and fast construction. In the process of railway and highway construction, the construction of railways or highways per kilometer requires permanent occupation of about 20,000 square meters of land. In the pipeline construction, the temporary land occupation per kilometer is about 18,000 square meters, and 99% after completion. The land can still be restored and used, and the permanent land occupation is small, and the management can also be laid on the rivers and the seabed without affecting shipping.
In the four major modes of transportation, the construction of oil pipelines also has the advantage of rapid construction. The practice data of foreign transportation system construction shows that the construction period of oil and gas pipelines is generally more than 30% shorter than the railway construction period of the same transportation volume.
3. Large oil and gas transportation volume. Railway tankers usually transport about 2,000 tons of oil at a time. If an oil field produces 20 million tons of crude oil per year (the annual output of Daqing Oilfield is about 50 million tons), it needs to pump 10,000 oil tankers full of crude oil from the oil field every year, and return the same number of empty vehicles, equivalent to 55 trains per day. Tank trucks enter and leave the oil field, which is very stressful for rail transport. This kind of production only needs to build a pipe with a diameter of 720 mm, and it can easily transport 20 million tons of crude oil every year.
4. High security performance. For the transportation of oil and gas resources, the transportation mode of cars and trains is very dangerous, and it is called “active bomb” in foreign countries. The management is confined in the underground and has high safety. And the oil and gas pipeline transportation has replaced the traditional mode of transportation by car, train and tanker, which has reduced the accident caused by traffic congestion to a certain extent.
5. In addition, management transportation also has less transportation loss, no “three wastes” emissions, less risk of leakage, less environmental pollution, less impact on bad weather, small equipment maintenance, easy management, and easy remote centralized monitoring. And so on. Therefore, oil and gas pipeline transportation is the best choice for oil and gas resource transportation.

Source: China LPG Pipeline Manufacturer – Yaang Pipe Industry Co., Limited (www.steeljrv.com)

(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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