Installation Principles of Pneumatic Control Valves
1. The installation position of pneumatic control valves should be at a certain height from the ground, and there should be a certain space between the upper and lower parts of the valve to facilitate disassembly and repair of the valve. For regulating valves equipped with a pneumatic valve positioner and handwheel, it is necessary to ensure convenient operation, observation and adjustment.
2. The regulating valve should be installed on the horizontal pipeline, and vertical to the pipeline from top to bottom. Generally, it should be supported under the valve to ensure stability and reliability. For special occasions, when it is necessary to install the regulating valve horizontally on the vertical pipeline, the regulating valve should also be supported (except for the small-diameter regulating valve). When installing, avoid bringing additional stress to the regulating valve.
3. The working environment temperature of the regulating valve should be between -30℃ and 60℃ and the relative humidity should not be greater than 95%.
4. There should be straight pipe sections in the front and rear positions of the regulating valve, the length of which is not less than 10 times the pipe diameter (10D), so as to avoid the straight pipe sections of the valve being too short and affect the flow characteristics.
5. When the diameter of the regulating valve is different from that of the processing pipeline, the reducer should be used for the connection. When installing the small-diameter regulating valve, a screw connection can be used. The fluid direction arrow on the valve body should be consistent with the fluid direction.
6. It is important to set the bypass pipe. The purpose is to facilitate switching or manual operation, and the regulator can be overhauled without stopping.
7. Before installation, the regulating valve should thoroughly remove foreign matters in the pipeline, such as dirt and welding slag.
Guide for Installing Pneumatic Control Valves
1. In order to ensure the safe and reliable operation of the regulating valve, horizontal installation should be adopted as much as possible. The straight pipe length of 10D should be guaranteed before and after the valve, and installation in places with high vibration intensity should be avoided. For example, the outlet position of the pump should be extended as far as possible to avoid damage to the regulating valve.
2. Ensure that the regulating valve and the processing pipeline are in the same straight line, and keep the actuator vertical at the same time. Bolts should be stud bolts. Gaskets should use metal wound gaskets that can be reused many times to ensure the sealing reliability of the regulating valve.
3. Ensure that the regulating valve has enough maintenance space in future use. Generally, the regulating valve is equipped with a negative line, which can be switched in case of an emergency of the throttle valve. However, when installing the negative line, attention should be paid to leaving a certain maintenance space for the regulating valve, which is generally not less than 50 CM.
4. Replace the valve core and valve seat. For regulating valves with a handwheel mechanism, turn the handwheel mechanism to the limit position, and loosen the cross-connecting block between the pushrod and the valve core of the regulating valve with a special hexagon wrench, so as to disconnect the connection between the actuator and the valve core. Loosen the upper bonnet screw to remove the whole upper bonnet together with the actuator. You can use special tools to replace the valve core seats respectively, and then replace them with new ones.
5. Replace the actuator. Pay attention to the verticality (vertical type) or levelness (horizontal type) of the air tank during installation. The cylinder must move freely up and down without jamming. To facilitate maintenance, the starting actuator should be installed near the ground or floor. When a valve positioner or first-round mechanism is installed, it is more important to ensure the convenience of observation, adjustment and operation. The function of the first-round mechanism: in case of an accident, it can be used to manually operate the regulating valve directly without pneumatic drive.
2. The regulating valve should be installed on the horizontal pipeline, and vertical to the pipeline from top to bottom. Generally, it should be supported under the valve to ensure stability and reliability. For special occasions, when it is necessary to install the regulating valve horizontally on the vertical pipeline, the regulating valve should also be supported (except for the small-diameter regulating valve). When installing, avoid bringing additional stress to the regulating valve.
3. The working environment temperature of the regulating valve should be between -30℃ and 60℃ and the relative humidity should not be greater than 95%.
4. There should be straight pipe sections in the front and rear positions of the regulating valve, the length of which is not less than 10 times the pipe diameter (10D), so as to avoid the straight pipe sections of the valve being too short and affect the flow characteristics.
5. When the diameter of the regulating valve is different from that of the processing pipeline, the reducer should be used for the connection. When installing the small-diameter regulating valve, a screw connection can be used. The fluid direction arrow on the valve body should be consistent with the fluid direction.
6. It is important to set the bypass pipe. The purpose is to facilitate switching or manual operation, and the regulator can be overhauled without stopping.
7. Before installation, the regulating valve should thoroughly remove foreign matters in the pipeline, such as dirt and welding slag.
Guide for Installing Pneumatic Control Valves
1. In order to ensure the safe and reliable operation of the regulating valve, horizontal installation should be adopted as much as possible. The straight pipe length of 10D should be guaranteed before and after the valve, and installation in places with high vibration intensity should be avoided. For example, the outlet position of the pump should be extended as far as possible to avoid damage to the regulating valve.
2. Ensure that the regulating valve and the processing pipeline are in the same straight line, and keep the actuator vertical at the same time. Bolts should be stud bolts. Gaskets should use metal wound gaskets that can be reused many times to ensure the sealing reliability of the regulating valve.
3. Ensure that the regulating valve has enough maintenance space in future use. Generally, the regulating valve is equipped with a negative line, which can be switched in case of an emergency of the throttle valve. However, when installing the negative line, attention should be paid to leaving a certain maintenance space for the regulating valve, which is generally not less than 50 CM.
4. Replace the valve core and valve seat. For regulating valves with a handwheel mechanism, turn the handwheel mechanism to the limit position, and loosen the cross-connecting block between the pushrod and the valve core of the regulating valve with a special hexagon wrench, so as to disconnect the connection between the actuator and the valve core. Loosen the upper bonnet screw to remove the whole upper bonnet together with the actuator. You can use special tools to replace the valve core seats respectively, and then replace them with new ones.
5. Replace the actuator. Pay attention to the verticality (vertical type) or levelness (horizontal type) of the air tank during installation. The cylinder must move freely up and down without jamming. To facilitate maintenance, the starting actuator should be installed near the ground or floor. When a valve positioner or first-round mechanism is installed, it is more important to ensure the convenience of observation, adjustment and operation. The function of the first-round mechanism: in case of an accident, it can be used to manually operate the regulating valve directly without pneumatic drive.
