Correctly selecting valve types and materials is of great significance to ensuring the safe and stable operation of the gas pipeline system. The following will introduce in detail the commonly used valve types and applicable materials for gas pipelines.
Gate valve
Working principle
: The gate valve uses the gate to move vertically along the center line of the valve seat to open and close the valve. The sealing surface between the gate and the valve seat fits tightly to prevent gas leakage. When the gate is fully opened, the gas can flow unimpeded in the pipeline with less flow resistance.
Features
Advantages
: Small fluid resistance, small opening and closing force, can be used for large-diameter pipelines. Good sealing performance, in the fully open state, the gate can effectively cut off the gas flow and reduce the possibility of leakage. Simple structure, easy maintenance, long service life.
Disadvantages
: Slow opening and closing speed, not suitable for occasions with frequent operations. When closed, if there are impurities and particles, it may affect the sealing performance of the gate and the valve seat.
Applicable scenarios
: Commonly used in gas transmission main pipelines, inlets of large gas equipment, and other occasions with large flow requirements and no need for frequent opening and closing. For example, the main pipeline in the urban gas transmission and distribution system, the intake pipeline of large industrial gas users, etc.
Common materials
Valve body material
: Generally, ductile iron, cast steel, etc. are used. Ductile iron has good corrosion resistance and mechanical properties, relatively low cost, and is suitable for medium and low pressure gas pipelines. Cast steel has higher strength and pressure resistance and can be used for high pressure gas pipelines.
Gate material
: Usually stainless steel or copper alloy. Stainless steel has good corrosion resistance and wear resistance, which can ensure that the gate is not easily damaged in long-term use and maintain good sealing performance. Copper alloy has better corrosion resistance and bite resistance, especially suitable for some occasions with extremely high sealing requirements.
Sealing surface material
: Commonly used are rubber, polytetrafluoroethylene (PTFE), etc. The rubber sealing surface has good elasticity and sealing performance, and can adapt to a certain degree of valve wear and deformation, but its temperature resistance and corrosion resistance are limited. The PTFE sealing surface has excellent corrosion resistance, temperature resistance and self-lubrication, and can maintain good sealing performance in a wide temperature range, and is suitable for various gas media.
Ball valve
Working principle
: There are circular through holes on the ball of the ball valve, and the valve is opened and closed by rotating the ball. When the through hole of the ball is aligned with the axis of the pipeline, the valve is in the open state, and the gas can pass smoothly; when the ball rotates 90 degrees and the through hole is perpendicular to the axis of the pipeline, the valve is closed and the gas flow is cut off.
Features
Advantages
: Simple structure, small size and light weight. Fast opening and closing speed, easy operation, suitable for occasions with frequent operations. Good sealing performance, the seal between the ball and the valve seat is tight, which can effectively prevent gas leakage. The flow resistance is extremely small and almost negligible, which is conducive to the smooth transmission of gas.
Disadvantages
: In a high temperature environment, the materials of the ball and the valve seat may deform, affecting the sealing performance. For large-diameter ball valves, the manufacturing and installation costs are relatively high.
Applicable scenarios
: Widely used in urban gas transmission and distribution systems, industrial gas pipelines, and gas pressure regulating stations. Especially in some pipeline systems that require rapid opening and closing, such as gas emergency shut-off devices, gas metering device inlets and outlets, ball valves have been widely used.
Common materials
Valve body materials
: Common ones are cast steel, stainless steel, and aluminum alloy. Cast steel valve bodies have high strength and good pressure resistance, and are suitable for high-pressure gas pipelines. Stainless steel valve bodies have excellent corrosion resistance and can resist the erosion of impurities and moisture in gas. They are often used in occasions with high corrosion resistance requirements. Aluminum alloy valve bodies have the characteristics of light weight and good thermal conductivity, and are suitable for some occasions with weight requirements, such as gas filling systems for gas vehicles.
Ball body material
: Generally, stainless steel or copper alloy is used. Stainless steel spheres have the characteristics of high strength, wear resistance, and corrosion resistance, which can ensure the stability of the shape and performance of the spheres in long-term use. Copper alloy spheres have better corrosion resistance and cavitation resistance, and are especially suitable for gas pipelines containing trace corrosive media.
Valve seat material
: Usually polytetrafluoroethylene (PTFE), metal or rubber. PTFE valve seats have good sealing, corrosion resistance and self-lubrication, and can adapt to different gas media and working temperatures. Metal valve seats have higher strength and temperature resistance, and are suitable for high-temperature and high-pressure gas pipelines. Rubber valve seats have good sealing performance and low cost, but their temperature resistance and corrosion resistance are relatively poor, and are generally used in low-pressure and normal-temperature gas pipelines.
Butterfly valve
Working principle
: The butterfly valve controls the opening of the valve by rotating the butterfly plate, thereby adjusting the flow of gas. The butterfly plate rotates around the axis in the valve body. When the butterfly plate is parallel to the pipeline axis, the valve is in a fully open state; when the butterfly plate rotates to be perpendicular to the pipeline axis, the valve is closed.
Features
Advantages
: Compact structure, small size, light weight, and small installation space requirements. Flexible operation, fast opening and closing speed, can be used in occasions where the flow is frequently adjusted. The flow resistance is small, and the pressure loss of gas passing through the valve is small in the open state.
Disadvantages
: The sealing performance is relatively poor, especially in high pressure and high temperature environments, leakage may occur between the butterfly plate and the valve seat. The adjustment accuracy of the butterfly valve is relatively low, and it is not suitable for occasions where very precise flow control is required.
Applicable scenarios
: It is commonly used in the flow regulation of urban gas medium-pressure pipelines, industrial gas pipelines, and ventilation systems in places such as gas boiler rooms. For example, in gas pressure regulating stations, butterfly valves can be used to adjust the flow of gas to meet the needs of different users.
Common materials
Valve body material
: Generally cast iron, cast steel or stainless steel are used. Cast iron valve bodies have good casting properties and corrosion resistance, low cost, and are suitable for medium and low pressure gas pipelines. Cast steel valve bodies have high strength and can withstand high pressures, and can be used for high-pressure gas pipelines. Stainless steel valve bodies have excellent corrosion resistance and hygienic properties, and are suitable for some occasions with high requirements for gas quality.
Butterfly plate material
: Usually carbon steel, stainless steel or aluminum alloy. Carbon steel butterfly plates have high strength and low cost, but poor corrosion resistance and require anti-corrosion treatment. Stainless steel butterfly plates have good corrosion resistance and oxidation resistance and can be used for a long time in harsh gas environments. Aluminum alloy butterfly plates are light and corrosion-resistant, and are suitable for some occasions that require weight and corrosion resistance.
Valve seat material
: Common ones include rubber, polytetrafluoroethylene (PTFE), etc. The rubber valve seat has good elasticity and sealing, can adapt to the rotation of the butterfly plate, and has low cost, and is suitable for low-pressure, normal temperature gas pipelines. The PTFE valve seat has excellent corrosion resistance, temperature resistance and self-lubrication, can maintain good sealing performance at higher temperatures and pressures, and is suitable for medium and high pressure gas pipelines.
Globe valve
Working principle
: The globe valve uses the valve disc to move along the center line of the valve seat to open and close the valve. When the valve disc rises, the gas can flow through the gap between the valve seat and the valve disc; when the valve disc drops and fits tightly on the valve seat, the valve closes and cuts off the gas flow.
Features
Advantages
: Good sealing performance, the sealing surface between the valve disc and the valve seat adopts a forced sealing method, which can effectively prevent gas leakage. It has certain throttling and flow adjustment functions, and the gas flow can be accurately adjusted by controlling the opening of the valve disc.
Disadvantages
: The fluid resistance is large, and a large pressure loss will occur when the gas passes through the stop valve. The opening and closing force is large, and the operation is relatively laborious. It is not suitable for large-diameter pipelines and frequent operations.
Applicable scenarios
: Commonly used in some parts of the gas pipeline system that require precise flow and pressure adjustment, such as gas pressure regulating devices, gas metering devices, and the inlet of some small gas equipment. For example, on the air intake pipeline of a gas boiler, the stop valve can be used to accurately control the flow of gas to ensure the normal combustion of the boiler.
Common materials
Valve body material
: Mainly cast steel, stainless steel and bronze. The cast steel valve body has high strength and good pressure resistance, and is suitable for high-pressure gas pipelines. The stainless steel valve body has good corrosion resistance and can resist the erosion of corrosive media in the gas. It is often used in occasions with high corrosion resistance requirements. The bronze valve body has excellent corrosion resistance and wear resistance, and is suitable for some gas pipelines with extremely high requirements for sealing performance and corrosion resistance.
Valve disc material
: Generally, stainless steel or copper alloy is used. The stainless steel valve disc has the characteristics of high strength, wear resistance and corrosion resistance, which can ensure the stability of the shape and performance of the valve disc in long-term use and maintain a good sealing effect. The copper alloy valve disc has better corrosion resistance and cavitation resistance, and is especially suitable for gas pipelines containing trace corrosive media.
Sealing surface material
: Commonly used are cemented carbide, polytetrafluoroethylene (PTFE), etc. The cemented carbide sealing surface has the characteristics of high hardness, wear resistance and corrosion resistance, and can maintain good sealing performance under high temperature, high pressure and frequent opening and closing conditions. The PTFE sealing surface has excellent corrosion resistance, temperature resistance and self-lubrication, can achieve good sealing in a wide temperature range, and is suitable for various gas media.
Safety valve
Working principle
: The safety valve is an automatic protection device. When the pressure in the gas pipeline exceeds the specified value, the safety valve automatically opens and discharges the gas to a safe place to prevent the pipeline system from exploding or other safety accidents due to overpressure. When the pressure in the pipeline returns to the normal range, the safety valve automatically closes.
Features
Advantages
: It can effectively protect the safety of the gas pipeline system and prevent overpressure accidents. It is sensitive and responsive, and can be opened and closed in a short time to ensure the stability of the pressure in the pipeline. It has reliable sealing performance and can ensure that the gas will not leak under normal working pressure.
Disadvantages
: Regular calibration and maintenance are required to ensure its reliable performance. If the safety valve is opened frequently, it may cause problems such as gas leakage and environmental pollution.
Applicable scenarios
: It is widely used in various links of gas production, storage, transportation and use, such as gas storage tanks, gas compressors, gas pressure regulating stations, and pipeline systems of industrial and civil gas users. For example, in the urban gas transmission and distribution system, the safety valve is usually installed on the inlet and outlet pipelines of the gas pressure regulating station to prevent pipeline overpressure caused by failure of the pressure regulating device
Common materials
Valve body material
: Generally cast steel, stainless steel, etc. are used. The cast steel valve body has high strength and can withstand high pressure, which is suitable for high-pressure gas pipeline systems. The stainless steel valve body has good corrosion resistance and can resist the erosion of impurities and moisture in the gas. It is often used in occasions with high corrosion resistance requirements.
Valve core material
: Usually stainless steel or copper alloy. The stainless steel valve core has the characteristics of high strength, wear resistance and corrosion resistance, which can ensure the shape and performance of the valve core in long-term use and ensure the reliable operation of the safety valve. The copper alloy valve core has better corrosion resistance and cavitation resistance, and is especially suitable for gas pipelines containing trace corrosive media.
Spring material
: Generally high-quality spring steel or stainless steel springs are used. Spring steel has high elasticity and high strength, and can provide sufficient elastic force to open and close the safety valve under the specified pressure. Stainless steel springs have better corrosion resistance, can maintain stable performance in harsh gas environments, and extend the service life of the safety valve.
Plug valve
Working principle
: The plug valve opens and closes the valve by rotating the plug body with a through hole. When the through hole on the plug body is aligned with the pipeline axis, the valve opens and the gas can pass through; the plug body rotates a certain angle to stagger the through hole with the pipeline axis, the valve closes, and the gas flow is cut off.
Features
Advantages
: Simple structure, easy operation, fast opening and closing speed. Small flow resistance, small pressure loss when gas passes through the plug valve. It has good sealing performance and can effectively prevent gas leakage.
Disadvantages
: The wear between the plug body and the valve seat is large, especially in frequent operation and gas media containing impurities, which is easy to affect the sealing performance. Not suitable for large-diameter pipelines and high-pressure pipelines.
Applicable scenarios
: Commonly used in some gas pipeline systems that do not require high flow control but need to be opened and closed quickly, such as the intake pipelines of small gas boilers and gas water heaters. In some gas laboratories or small gas equipment, plug valves have also been widely used.
Common materials
Valve body material
: Generally cast iron, cast steel or brass are used. Cast iron valve body has low cost and certain corrosion resistance, which is suitable for medium and low pressure gas pipelines. Cast steel valve body has high strength and can withstand higher pressure, which can be used for high pressure gas pipelines. Brass valve body has good corrosion resistance and decorativeness, and is often used in some occasions with high requirements for appearance and corrosion resistance.
Plug body material
: Usually copper alloy or stainless steel. Copper alloy plug body has good corrosion resistance and wear resistance, and can maintain good sealing performance in long-term use. Stainless steel plug body has higher strength and corrosion resistance, which is suitable for some gas pipelines with high requirements for corrosion resistance and wear resistance.
Sealing surface material
: Commonly used are rubber, polytetrafluoroethylene (PTFE), etc. The rubber sealing surface has good elasticity and sealing, can adapt to the rotation of the plug body, and has low cost, which is suitable for low-pressure and normal temperature gas pipelines. PTFE sealing surface has excellent corrosion resistance, temperature resistance and self-lubrication, can maintain good sealing performance in a wide temperature range, and is suitable for various gas media.
Regulating valve
Working principle
: The regulating valve adjusts the flow and pressure of the gas by changing the opening of the valve according to the instructions of the control system to meet the needs of different users. The regulating valve is usually composed of an actuator and a valve body. The actuator drives the valve core to move according to the control signal, thereby changing the flow area of the valve.
Features
Advantages
: It has precise flow and pressure regulation functions and can adjust the gas supply in real time according to user needs. The adjustment range is wide and can achieve stable regulation within a large flow and pressure range. The response speed is fast and can quickly adapt to changes in system parameters.
Disadvantages
: Complex structure and high cost. It has high requirements for installation and maintenance and requires professional personnel to operate and maintain it.
Applicable scenarios
: It is widely used in urban gas transmission and distribution systems, industrial gas users, and gas power generation. For example, in urban gas pressure regulating stations, regulating valves are used to accurately adjust the pressure and flow of gas according to the gas demand in different periods of time to ensure the stability and safety of gas supply.
Common materials
Valve body material
: Generally cast steel, stainless steel, etc. Cast steel valve body has high strength and good pressure resistance, suitable for high-pressure gas pipeline systems. Stainless steel valve body has good corrosion resistance and can resist the erosion of impurities and moisture in gas, and is often used in occasions with high corrosion resistance requirements.
Valve core material
: Usually stainless steel or copper alloy. Stainless steel valve core has high strength, wear resistance and corrosion resistance, which can ensure the shape and performance of the valve core in long-term use and achieve precise flow regulation. Copper alloy valve core has better corrosion resistance and cavitation resistance, especially suitable for gas pipelines containing trace corrosive media.
Sealing surface material
: Commonly used are polytetrafluoroethylene (PTFE), metal, etc. PTFE sealing surface has excellent corrosion resistance, temperature resistance and self-lubricating properties, can maintain good sealing performance in a wide temperature range, and achieve precise flow regulation. Metal sealing surface has higher strength and temperature resistance, suitable for high-temperature and high-pressure gas pipelines.
124.webp)
294.webp)
476.webp)
420.webp)
146.webp)
460.webp)
287.webp)
274.webp)
688.webp)
