TM 9-4120-399-14
(6) Observe that temperature indicated remains stable for a minimum of two minutes,
then find saturation temperature for pressure indicated on gage, using Table 5-1. For example:
The saturation temperature for a refrigerant pressure of 69 psig (4.85 kg/cm2) is 40 deg. F (4.4
deg. C).
(7) Compare the saturation temperature with indicated temperature. The indicated
temperature should be 16 .5 deg. F (8.9 .3 deg. C) higher than the saturation temperature.
For example: With a 40 deg. saturation temperature, the thermometer should read 65 5 deg.
F (18 2.7 deg. C).
If indicated temperature is not within above limits, liquid quencher
expansion valve is not functioning properly and must be replaced.
b. Removal
(1) Unwrap insulation from suction line (13) to expose sensing bulb (12).
(2) Loosen three flare nuts (1), (2), and (3) that secure tubing to liquid quencher
expansion valve (4).
(3) Remove screw (5), lock washer (6), and nut (7) from clamp (8).
(4) Remove two screws (9) and two nuts (10) from clamps (11) that secure sensing bulb
(12). Discard clamps (9).
(5) Note position of sensing bulb (12) on suction line (13).
(6) Remove liquid quencher expansion valve (4) from clamp (8).
c. Installation.
(1) Install liquid quencher expansion valve (4) to clamp (8).
(2) Tighten three flare nuts (1), (2), and (3) on the liquid quencher expansion valve (4).
(3) Secure liquid quencher expansion valve (4) to clamp (8) with screw (5), lock washer
(6), and nut (7).
(4) Coil sensing bulb (12) capillary into two loops.
(5) Place the sensing bulb (12) on suction line (13) such that bulb is in contact with
clean, bare tubing.
(6) Secure sensing bulb (12) to suction line (13) with two clamps (11) supplied with
liquid quencher expansion valve (4) and with two screws (9) and two nuts (10) (also supplied
with valve).
(7) Wrap sensing bulb (12) and capillary with insulating tape (Appendix E, Item 24).
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