Refrigeration & Air Conditioning USCG Question #1010 (Set 20)

Of the various possible methods shown in the illustration, which is the correct method of attaching a TXV feeler bulb to a large line (7/8" and larger) with a horizontal run? Illustration GS-RA-50 Illustration GS-RA-50: the U.S. Coast Guard has not released this illustration.

Official USCG Answer & Rule Citation

Correct Answer: Option C — C

On large horizontal suction lines measuring 7/8 inch and above, the thermostatic expansion valve feeler bulb must be mounted on the lower quadrant of the pipe circumference to ensure proper thermal contact with liquid-vapor mixture flow.

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