Leak Checking Refrigeration System

TM 5-4130-234-13&P

f. Crack the refrigerant bottle valve to purge the hose

2-5.

Evacuation of Refrigeration System

assembly of air, then tighten hose assembly fitting on valve

a. Open suction and receiver valves of the

(12).

refrigeration system and purge system with dry nitrogen.

g. Open valve (12) and refrigerant bottle valve.

b. Connect hose assembly (8, fig. 2-4) with gaskets

h. Fill reservoir to desired level as indicated on scale

(2, 3) between refrigeration system receiver valve and

(8); slowly open valve (5) as required to expedite filling.

valve (14, fig. 2-3).

c. Connect hose assembly (9, fig. 2-4) with gaskets

WARNING

(2, 3) between refrigeration system suction valve and union

(24, fig. 2-3).

d. Open refrigeration system receiver and suction

Exercise care in disconnecting hose

valves, and open valves (1, 2).

assembly from refrigerant bottle and

e. Set circuit breaker (22) to ON and switch (21) to

valve to prevent refrigerant from getting

VAC ON.

in the eyes or permanent damage to the

NOTE

eyes may result.

Application of heat to refrigeration system

i. Close valves (5, 12) and refrigerant bottle valve.

will expedite evacuation.

Disconnect hose assembly and cap valves (5, 12).

f. Evacuate refrigeration system for two hours to 200

microns or lower as indicated on gage (26).

2-4.

Leak Checking Refrigeration System

NOTE

a. Pressurize refrigeration system to approximately

To determine level of vacuum in

15 psig, using dry nitrogen and refrigerant or refrigerant.

refrigeration system, close valve (2) and

b. Connect refrigeration system charge valve to union

observe indication of gage (26).

(18), using hose assembly (6, fig. 2-4) with gaskets (3, 4).

g. At end of the two hour evacuation period, close

c. Connect leak detector (11) to connector (19, fig. 2-

refrigeration system suction and receiver valves. Set

3).

switch (21) and circuit breaker (22) to OFF.

d. Ventilate area -of refrigeration system to be leak-

h. Remove hose assemblies and proceed directly to

checked.

charging refrigeration system with oil or charging

e. If leak detector is being used for the first time,

refrigeration system with refrigerant.

remove and discard screw from cap of REFERENCE LEAK

bottle and allow REFERENCE LEAK to stabilize for 15

2-6.

Charging Refrigeration System with OIL

minutes. Make certain REFERENCE LEAK bottle contains

CAUTION

a quantity of refrigerant, as observed through window in

Use care in storage and handling of

chassis.

refrigeration oil to prevent absorption of

f. Point probe of leak detector toward floor and

moisture

and

other

atmospheric

observe airflow ball, located in probe; ball must rise and

contaminants.

float above tip of probe. If ball fails to rise, tap probe

a. Uncap and open valve 16).

lightly to make certain ball is not stuck.

b. Open valves (1, 2), cap union (25), and uncap

g. Set leak detector SENSITIVITY switch to LOW

union (24).

(used when element is new and when detecting large

c. Connect hose assembly (6, fig. 2-4) between union

leaks), place tip of probe close to opening in REF LEAK

(24, fig. 2-3) and valve (6), using a 1/2 X 3/8 inch reducer

cap, and adjust BALANCE control until neon lamp in probe

on union (24).

just ceases flashing.

d. Cap and close valve (11).

h. Hold leak detector probe as close as possible to

e. Connect hose assembly (6, fig. 2-4) with gaskets

the area being checked and move the tip at a rate no

13, 4) between valve (11, fig. 2-3) and container filled with

greater than one inch per second along seams and joints

refrigeration oil.

suspected of leakage. When the probe encounters a leak,

f. Set circuit breaker (22) to ON and switch (21) to

the flashing rate of the neon lamp will increase and will

VAC ON.

continue to flash at the faster rate as long as the probe is

g. Observe gage (26) until reading is slightly below

held near the leak.

1000 microns; then close valve (1). Slowly open valve (11)

and observe scale on beaker (4) until oil level reaches

1000 ML graduation. Close valves (6, 11).

2-8