TM 9-4120-403-14
(7) Compare the saturation temperature with indicated temperature. The indicated temperature should be 25 +/50
(13. 9 +/2. 20C) higher than the saturation temperature. For example: With a 400 saturation temperature, the
thermometer should read 65 +/50F. If indicated temperature is not within above limits, quench valve is not functioning
properly and should be replaced.
Replacement
(1) Discharge the refrigerant system per paragraph 5-7.
(2) Unwrap insulation tubing from suction line so that sensing bulb is exposed. Note location and position of bulb
for reinstallation. Loosen screws and nuts in clamps. Pull bulb out of clamps.
(3) Using wrench, remove two cap screws, lockwashers, flat washers, and spacers that attach valve body to
bracket and power assembly.
(4) Carefully remove the power assembly and cage assembly.
NOTE
If valve body flange is not damaged, do not remove (debraze) it from the system.
(5) If valve body flange is to be removed, purge the system with nitrogen and debraze the two tubes. (See para 5-
8 and 5-9. )
(6) If valve body flange was removed, purge the system with nitrogen and braze the two tubing joints. (See para
(7) Coat cage assembly gaskets with oil.
(8) Be sure that valve components are properly assembled and aligned. Secure power assembly to body flange.
(9) Secure valve assembly with two cap screws, lockwashers, flat washers, and spacers.
(10) Insert sensing bulb into its mounting clamps in its original position, and tighten the screws and nuts. Be sure
sensing bulb is installed in the original position and is making good metal-to-metal contact with suction line.
(11) Cut to length and install insulation tubing over sensing bulb. Be sure insulation extends beyond both ends of
bulb
(12) Wrap insulation tubing with one layer of insulation tape.
(13) Wrap both ends of insulation tape with two layers of pressure-sensitive tape.
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