Gas pressure reducing valve use and precautions
2021-09-09 08:04:29
The installation of the gas pressure reducer must ensure safety, ensure performance, ease of operation and maintenance, and save installation costs. Let's talk about the specific issues that need to be paid attention to during installation. The inspection of the gas pressure reducer before installation mainly includes the following contents: appearance, static characteristics, leakage amount, full-load time of no-load, compressive strength, insulation performance, air tightness and sealing, etc. The first five items are mandatory inspection items. . Of course, there are certain requirements for the place to be inspected. For example: the ambient temperature is required to be 10 to 35 ° C; the relative humidity of the air is not more than 75%; the site has sufficient space, and the light is sufficient or there are lighting conditions; there is no strong vibration source and strong magnetic field interference; the power source and the gas source are in compliance with Request and so on. Gas pressure reducers and accessories are subject to random vibrations induced by the vehicle during transportation and various shocks during loading and unloading, as well as changes in ambient temperature and humidity during transportation and storage. It may cause changes in the performance of the gas pressure reducer and accessories. Therefore, it is necessary to perform some performance tests before installation. In the installation, about 20% to 30% of the cost is the result of these two. For example, in order to meet the needs of continuous production of equipment, many industrial systems are equipped with a shut-off valve and a bypass valve. The shut-off valve is used to block the gas pressure reducer. A bypass valve is required for maintenance, and a shut-off valve or bypass is added. Valves, it is necessary to increase the corresponding connecting pipelines, which will increase the cost; and some piping schemes, only one shut-off valve can play the role of shutting off the gas pressure reducer during maintenance, such piping scheme will save some installation costs . Installation of the bleed valve Any piping design and installation will inevitably accumulate high pressure fluid when shutting off. If the potential energy of the accumulated fluid is large, install a bleed valve on both sides of the gas pressure reducer. After the system is shut off, the energy of the high-pressure fluid remaining in the gas pressure reducer can be released, protecting the safety of the personnel, facilitating the maintenance of the gas pressure reducer, and also selecting a discharge valve that can limit the flow rate.
The leak-proof installation process does not allow the gas pressure reducer to leak. During use, if a gap or micropore is formed in the filler culvert, flange gasket, etc., leakage may occur. If the operating conditions of the fluid medium are harsh, such as high temperatures, high pressures, and corrosive fluids, the damage will increase and the risk of leakage will be greater. There are many ways to prevent leakage. In the installation process, the choice of packing, the choice of sealing method, and the selection of gas pressure reducer with good sealing performance are all factors that must be considered. When the gas pressure reducer is disassembled for maintenance, the bypass valve can be used to operate the production process. When the controlled flow rate is too large and the gas pressure reducer cannot be adjusted normally, as a countermeasure, the bypass valve can also be used as a parallel connection scheme of the gas pressure reducer to control the process. In order to reduce costs, the large-diameter gas pressure reducer is equipped with a hand wheel actuator that can be operated in place of the bypass valve. The bypass valve should be installed for easy operation. It is combined with the gas pressure reducer and the upstream and downstream shut-off valves to form a gas pressure reducer group. Therefore, when installing the gas pressure reducer, it should be considered together with the shut-off valve and the bypass valve, and the construction and installation should be completed at the same time. The nominal diameter of the bypass valve is the same as the nominal diameter of the pipe, and the pressure rating is also consistent with the process withstand voltage rating. The length of the straight pipe between the upper and lower shut-off valves and the gas pressure reducer of the upstream and downstream shut-off valves and bypass valves of the gas pressure reducer shall take into account the resistance of the pipeline and the influence on the fluid flow state. The long length of the straight pipe section is conducive to the stability of the fluid after the shut-off valve, which can make the fluid flow smooth, reduce the influence of turbulence and reduce the noise; the length of the straight pipe section is short, and the fluid enters the gas pressure reducer after being stabilized by the shut-off valve, so that The noise increases, but the short length of the straight pipe section is beneficial to reduce the pipeline resistance, increase the pressure drop across the gas pressure reducer, and reduce the distortion of the flow characteristics, which is beneficial to the stable operation of the control system. Therefore, we should weigh the pros and cons and consider it comprehensively. According to experience, usually the upstream side should have a straight pipe section of 10D ~ 20D, and the downstream side has a straight pipe section of 3D ~ 5D (D is the pipe diameter), and if necessary, a rectifying device should be provided. The connected gas pressure reducer output signal of the gas pressure reducer output signal is a valve position signal, which may be an analog signal or a digital signal. Check that the valve position signal is correct while checking the gas pressure reducer input signal. When using a HART or intelligent electric valve positioner, check that the valve status information is correctly transmitted.
During the full stroke operation of the gas pressure reducer, pay attention to whether the valve core and the valve seat have mechanical vibration and abnormal noise.
The leak-proof installation process does not allow the gas pressure reducer to leak. During use, if a gap or micropore is formed in the filler culvert, flange gasket, etc., leakage may occur. If the operating conditions of the fluid medium are harsh, such as high temperatures, high pressures, and corrosive fluids, the damage will increase and the risk of leakage will be greater. There are many ways to prevent leakage. In the installation process, the choice of packing, the choice of sealing method, and the selection of gas pressure reducer with good sealing performance are all factors that must be considered. When the gas pressure reducer is disassembled for maintenance, the bypass valve can be used to operate the production process. When the controlled flow rate is too large and the gas pressure reducer cannot be adjusted normally, as a countermeasure, the bypass valve can also be used as a parallel connection scheme of the gas pressure reducer to control the process. In order to reduce costs, the large-diameter gas pressure reducer is equipped with a hand wheel actuator that can be operated in place of the bypass valve. The bypass valve should be installed for easy operation. It is combined with the gas pressure reducer and the upstream and downstream shut-off valves to form a gas pressure reducer group. Therefore, when installing the gas pressure reducer, it should be considered together with the shut-off valve and the bypass valve, and the construction and installation should be completed at the same time. The nominal diameter of the bypass valve is the same as the nominal diameter of the pipe, and the pressure rating is also consistent with the process withstand voltage rating. The length of the straight pipe between the upper and lower shut-off valves and the gas pressure reducer of the upstream and downstream shut-off valves and bypass valves of the gas pressure reducer shall take into account the resistance of the pipeline and the influence on the fluid flow state. The long length of the straight pipe section is conducive to the stability of the fluid after the shut-off valve, which can make the fluid flow smooth, reduce the influence of turbulence and reduce the noise; the length of the straight pipe section is short, and the fluid enters the gas pressure reducer after being stabilized by the shut-off valve, so that The noise increases, but the short length of the straight pipe section is beneficial to reduce the pipeline resistance, increase the pressure drop across the gas pressure reducer, and reduce the distortion of the flow characteristics, which is beneficial to the stable operation of the control system. Therefore, we should weigh the pros and cons and consider it comprehensively. According to experience, usually the upstream side should have a straight pipe section of 10D ~ 20D, and the downstream side has a straight pipe section of 3D ~ 5D (D is the pipe diameter), and if necessary, a rectifying device should be provided. The connected gas pressure reducer output signal of the gas pressure reducer output signal is a valve position signal, which may be an analog signal or a digital signal. Check that the valve position signal is correct while checking the gas pressure reducer input signal. When using a HART or intelligent electric valve positioner, check that the valve status information is correctly transmitted.
During the full stroke operation of the gas pressure reducer, pay attention to whether the valve core and the valve seat have mechanical vibration and abnormal noise.
Cooling Patch(Gel series)
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