Protective Measures for Valves Installation
May 27, 2020
Brief description:
1. When installing the valve, a filter and a flush valve are required to prevent metal, sand and other foreign matters from invading and damaging the sealing surface.
2. In order to keep compressed air purified, an oil-water separator or an air filter needs to be installed in front of the valve.
3. Considering that the working state of the valve can be checked during operation, instruments and check valves need to be set up.
4. In order to maintain the operating temperature, heat preservation facilities are provided outside the valve.
5. Before installing the valve, a safety valve or a check valve needs to be installed.
6. Considering the safety risks brought by the continuous operation of the valve, a parallel system or bypass system has been set up.
Details:
1. Protective facilities for check valves: In order to prevent leakage of check valves or backflow of media after failure, resulting in deterioration of product quality and adverse consequences such as accidents, one or two cut-off valves are installed at the front and rear of check valves. If two shut-off valves are provided, the check valve can be easily removed for maintenance.
2. Protective facilities for safety valves: No isolation valves are generally set before and after installation, which are only used in individual cases. If the medium force contains solid particles, which affects the safety valve that cannot be closed tightly after a trip-out, a gate valve with sealed lead shall be installed before and after the safety valve. The gate valve shall be fully opened. The gate valve and the safety valve shall be directly installed with a DN20 check valve open to the atmosphere. Steam heating is required for safety valves when the medium, such as wax, is in a solid state at room temperature, or when the temperature of light liquid and other media alike is lower than 0℃ as a result of decompression vaporization. Safety valves used for corrosive media, depending on the corrosion resistance of the valve, corrosion-resistant explosion-proof film shall be added at the inlet of the valve. Gas safety valves are generally equipped with a bypass valve according to its size for manual venting.
3. Protective facilities for pressure relief valves: The installation facilities for pressure relief valves generally come in three forms. Pressure gauges are installed in front of and behind the pressure reducing valve to facilitate observation of the pressure in front of and behind the valve. There is also a fully enclosed safety valve behind the main valve to prevent it from tripping as the pressure behind exceeds normal one after the valve fails, including the back-valve system. The drain pipe is installed in front of the cut-off valve before the main valve. It is mainly used for drainage and flushing. Some use drain valves for the same demands. The main function of the bypass pipe is to close the cut-off valves at the front and rear of the pressure reducing valve after it fails. Then you can open the bypass valve, and manually adjust the flow rate to provide a temporary circulation so that the pressure reducing valve can be expediently overhauled or replaced.
4. Protection facilities for drain valve: There are two types of drain valves with or without bypass pipes at the edge. Condensate recovery and non-recovery are available. Drain valves with a discharge capacity and other special functions can be installed in parallel. Drain valves with bypass valve is mainly used to discharge a large amount of condensed water when the pipeline starts to operate. It is inappropriate to use a bypass line to discharge condensate when repairing traps, as this will allow steam to escape into the return water system. Under normal circumstances, bypass pipes are not required. Only when there are strict requirements on heating temperature can bypass pipes be installed for thermal equipment in continuous working condition.
1. When installing the valve, a filter and a flush valve are required to prevent metal, sand and other foreign matters from invading and damaging the sealing surface.
2. In order to keep compressed air purified, an oil-water separator or an air filter needs to be installed in front of the valve.
3. Considering that the working state of the valve can be checked during operation, instruments and check valves need to be set up.
4. In order to maintain the operating temperature, heat preservation facilities are provided outside the valve.
5. Before installing the valve, a safety valve or a check valve needs to be installed.
6. Considering the safety risks brought by the continuous operation of the valve, a parallel system or bypass system has been set up.
1. Protective facilities for check valves: In order to prevent leakage of check valves or backflow of media after failure, resulting in deterioration of product quality and adverse consequences such as accidents, one or two cut-off valves are installed at the front and rear of check valves. If two shut-off valves are provided, the check valve can be easily removed for maintenance.
2. Protective facilities for safety valves: No isolation valves are generally set before and after installation, which are only used in individual cases. If the medium force contains solid particles, which affects the safety valve that cannot be closed tightly after a trip-out, a gate valve with sealed lead shall be installed before and after the safety valve. The gate valve shall be fully opened. The gate valve and the safety valve shall be directly installed with a DN20 check valve open to the atmosphere. Steam heating is required for safety valves when the medium, such as wax, is in a solid state at room temperature, or when the temperature of light liquid and other media alike is lower than 0℃ as a result of decompression vaporization. Safety valves used for corrosive media, depending on the corrosion resistance of the valve, corrosion-resistant explosion-proof film shall be added at the inlet of the valve. Gas safety valves are generally equipped with a bypass valve according to its size for manual venting.
3. Protective facilities for pressure relief valves: The installation facilities for pressure relief valves generally come in three forms. Pressure gauges are installed in front of and behind the pressure reducing valve to facilitate observation of the pressure in front of and behind the valve. There is also a fully enclosed safety valve behind the main valve to prevent it from tripping as the pressure behind exceeds normal one after the valve fails, including the back-valve system. The drain pipe is installed in front of the cut-off valve before the main valve. It is mainly used for drainage and flushing. Some use drain valves for the same demands. The main function of the bypass pipe is to close the cut-off valves at the front and rear of the pressure reducing valve after it fails. Then you can open the bypass valve, and manually adjust the flow rate to provide a temporary circulation so that the pressure reducing valve can be expediently overhauled or replaced.
4. Protection facilities for drain valve: There are two types of drain valves with or without bypass pipes at the edge. Condensate recovery and non-recovery are available. Drain valves with a discharge capacity and other special functions can be installed in parallel. Drain valves with bypass valve is mainly used to discharge a large amount of condensed water when the pipeline starts to operate. It is inappropriate to use a bypass line to discharge condensate when repairing traps, as this will allow steam to escape into the return water system. Under normal circumstances, bypass pipes are not required. Only when there are strict requirements on heating temperature can bypass pipes be installed for thermal equipment in continuous working condition.
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