Why is a manual valve also provided next to the electric valve?
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This post was last edited by feng_200108047 on 2011-9-1 17:44. Question: 1. When multiple automatic control valves are installed on a pipeline, under what circumstances is it necessary to have both an automatic control valve and a manual valve on the same pipeline? What is the reasoning behind this? 2. If used for transporting flammable and explosive liquids, which type of automatic control valve is suitable? What about acids and bases? 3. Why is a manual valve also provided next to the electric valve? Why is a manual valve installed alongside the electric valve?
The manual valve should serve to cut off the flow, thereby stopping the medium when there is a fault with the electric valve, which facilitates its repair
Reply to 1# zb030121eric: It is better to use pneumatic valves for flammable and explosive substances. Manual valves are used when it is necessary to repair electric valves; they can cut off the fluid flowing in the pipeline or provide a bypass route, and they can also be used for venting and discharge
For safety reasons. . Prevent failures. . Then it was manually cut off in an emergency, right?
1. The manual valve is used to prevent control valves from failing and ceasing to function properly, thereby facilitating maintenance and ensuring the normal operation of the equipment. 2. For flammable and explosive media, pneumatic valves are generally used, with solenoid valve boxes or explosion-proof solenoid valves along with positioners to control the opening and closing of the valves. The material used for lining the valves is chosen based on the specific properties of the medium; for example, carbon steel is usually sufficient for concentrated sulfuric acid, while valves made of 316 fluorinated material or even better materials are required for dilute sulfuric acid and hydrochloric acid. . . Acetic acid requires Monel alloy and the like. . . . 3. A manual valve is provided next to the electric valve; similarly, a safety factor is taken into account