Which one of the following is a generally accepted method for locally verifying that a manual valve is fully closed in a depressurized static piping system?
A. Check a downstream flow gauge to be indicating zero flow.
B. Visually observe the valve rising-stem threading to be fully exposed.
C. Attempt to turn the valve handwheel in the close direction and verify no movement.
D. Compare an upstream and downstream pressure gauge to ensure zero differential pressure.
Show Answer
Answer: C
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