Hand Control Valves


Thread Starter


Hi all,

I noticed the use of hand control valves in an oil well and i wonder why we still have to install manually controlled valves instead of having valves that can be automatically controlled all through.

Is there any regulatory requirement for having hand control valves installed?

Kindly enlighten me on this.

Remote operated valves are great and should be used when necessary for remote operation of a process. However, hand operated shutoff or blocking valves are required for maintenance to prevent exposure of maintenance personnel to the process fluid while they have removed a piece of equipment.

For example: to maintain a pump by changing its impeller requires first that the maintenance team first shut off the pump electrical supply and car-seal the breaker or switch. Then the pump body can be opened, old impeller removed, new impeller installed, and the pump body closed and bolted in place.

While the pump is open, the blocking valves around the pump prevent any remote operation that could cause process fluid from pouring down the pump intake line and contaminating the maintenance worker. During normal plant operation, these blocking valves are left in the open state.