Thank you all. I’ll rephrase the question: when the control valve for shutdown fails, the valve closes to 30% – how can this be achieved?
Thread Content
Thank you all. I’ll rephrase the question: when the control valve for shutdown fails, the valve closes to 30% – how can this be achieved?
Cylinder-type actuators are easier to adjust; pneumatic diaphragm actuators may not allow for such significant adjustments by modifying the valve stem. If, due to manufacturing reasons, the valve cannot be closed completely, it is recommended to replace it with a air-operated valve, but safety must be considered comprehensively.
How many steps are required to put an elephant in a refrigerator?
In terms of hardware, a sleeve can be made to hold the valve stem in place. . . Easy to implement, easy to remove. Haha
The key is to identify what the fault is, as different faults require different troubleshooting methods; however, it’s best to resolve the fault...
The fail-safe FC of the valve means that it closes in the event of a complete loss of gas and electrical signals. You asked that the valve be closed to 30%, so when will it be closed to 100%? The control scheme you provided isn’t complete! If it’s only for a specific interlock action, reducing it to 30% can also be achieved through a program. If it shuts down to 30% due to a fault, and complete shutdown is not possible, this can be achieved by modifying the valve (by changing the valve stem). In specific cases, specific explanations are needed; solutions are being considered!
First, open the valve to 30% and mark that position; then close the valve and manually adjust the zero point so that it is set at 30%. This way, the valve will close to 30% when a fault occurs