What can cause damage to the valve to the point that it will not seat and stop flow when closed?

A) Opening or closing a valve
B) Throttling a valve that is not designed for throttling
C) Failure to clean and lubricate valve stems
D) Improper closing of a valve on a high-pressure line


Answer: B
Explanation: A) Incorrect. Excessive force when opening or closing a valve can cause leakage and make the valve difficult to open or close.
B) Correct. Throttling a valve that is not designed for throttling can cause damage to the valve to the point that it will not seat and stop flow when closed.
C) Incorrect. Failure to clean and lubricate valve stems causes valve stem seizure or thread damage makes the valve difficult to open and close.
D) Incorrect. Improper closing of a valve on a high-pressure line can cause a leak in the environment.

Trades & Technology

You might also like to view...

Which of the following is on the front leg between the radius/ulna and the cannon bone?

a. pastern c. gaskin b. knee d. hock

Trades & Technology

When comparing costs and performance of different insulation materials, it is critically important to make sure that each of them will be installed according to RESNET ____ criteria and to the R-values specified.

A. Grade 1 B. Grade A C. Premium Grade D. Superior Grade

Trades & Technology

Using the reciprocal key on a calculator, the reciprocal of 4 is:

A. 4.0 B. 4.4 C. 0.4 D. 0.25

Trades & Technology

For t < 0, the circuit shown in Figure P5.68 is in DC steady state. The switch is closed at t = 0. Determine the current iL through the inductor for t > 0. Assume

R = 3k?, RS = 600?, VS = 2V, C = 2mF, and L = 1mH.

Trades & Technology