TM 9-4120-370-14
TO 35E9-229-1
5-27. LIQUID QUENCH EXPANSION VALVE - Continued.
NOTE
Except in a very hot climate, with room air temperature above 90F (32.2C), the refrig-
eration system will be in a bypass cycle with a maximum volume of hot discharge vapor
being recirculated back to suction side of compressor through pressure regulator valve
and quench valve.
(6)
Observe that temperature indicated remains stable for a minimum of two minutes, then find saturation tem-
perature for pressure indicted on gage. using table 5-1. For example: The saturation temperature for a
refrigerant pressure of 69 psig (4.85 kg/cm2) is 40F (4.4C).
(7)
Compare the saturation temperature with indicated temperature. The indicated temperature should be 25
5F (13.9 2.2C) higher than the saturation temperature. If indicated temperature is not within above
!imits, quench valve is not functioning properly and should be replaced.
Turn unit OFF.
(8)
Remove thermometer.
(9)
(10) Reinstall and tape in place tubing insulation that was removed from suction line tubing. If it was damaged,
replace with tubing insulation, item 17, Appendix E.
(11) Close service valves on unit.
(12) Remove gages or service manifold from service valves.
(13) Install valve stem and hose connection protective caps.
(14) Using screwdriver, secure service valve cover with six screws, lock washers, and flat washers.
Removal
c.
(1) Discharge the refrigerant system per paragraph 5-7.
(2) Unwrap insulation from suction line so that sensing bulb is exposed, Loosen screw and nut in clamp. Pull
bulb out of clamp.
(3) Using wrench, remove two cap screws, lock washers, flat washers, and spacers that attach valve body
to bracket and power assembly.
(4) Carefully remove the power assembly, cage assembly, and gaskets.
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
d. Installation
(1)
If valve body flange was removed, purge the system with nitrogen and braze the two tubing joints. (See
(2)
See Figure 535 for valve component arrangement.
Place cap screws, lock washers, flat washers, and spacers through bracket and valve body flange.
(3)
(4)
Be sure that valve components are properly assembled and alined. Secure power assembly to body flange.
Insert sensing bulb into its mounting loop clamp in its original position, and tighten the screw and nut. Be
(5)
sure sensing bulb is making good metaltometal contact with suction line.
Reinstall and tape in place tubing insulation that was removed from suction line tubing, If it was damaged,
(6)
replace with tubing insulation, item 17, Appendix E.
(7)
Replace the dehydrator. (See para 5-14.)
5-56