Control valve – Valve body and actuator

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A control valve consists of an actuator and a valve body; in normal use, it is common to see damage to the valve body, while damage to the actuator is less frequent. It can be said that giving more emphasis to the actuator than to the valve body is actually biased. The importance of the actuator is certainly undeniable, but it does not come into direct contact with the medium; rather, more attention needs to be paid to the selection of the valve body. In September, I visited a chemical plant where all the actuators were intact while the valve bodies were damaged. I went to the workshop to conduct an on-site inspection and found that the temperature of the medium was quite high (above 150 degrees), with the ambient temperature being around 40 degrees as well (as perceived by touch). The medium is primarily dilute sulfuric acid, with other impurities added to it. The materials used for the valves by the client vary widely – including plastic, PTFE, and rubber. I selected new materials and designs based on the actual operating conditions. The client ordered four units for testing, and they are still in production; the results will be known once they are delivered and put into use this month.