Replace pressure relief valve on receiver (1, FIGURE 4-10) as follows:

TM 55-1905-223-24-17

(1) Disconnect angle valve (5) at connections (3) and (4) and remove valve (5) from high side

refrigerant line at receiver outlet.

(2) Install new angle valve (5) at connections (3) and (4).

(3) Remove cap (1) and make sure valve is open by turning valve stem (2) fully counterclockwise.

Install cap (1).

(4) Open service valves and receiver outlet valve to allow refrigerant back into the system.

(5) Restore electrical power and run air conditioners to check for proper operation. Check refrigerant

sight glass and add R-22 refrigerant as required (paragraph 4-10).

(6) Remove "Out of Service" tag from circuit.

g. Replace pressure relief valve on receiver (1, FIGURE 4-10) as follows:

WARNING

PRESSURIZED GAS HAZARD. Refrigerant charge must be completely removed

from system before removing pressure relief valve from receiver.

(1) Remove any refrigerant left in system.

(2) Remove pressure relief valve (1) by turning hex fitting (2) at base of valve counterclockwise.

(3) Install new pressure relief valve (1) by turning hex fitting (2) clockwise until snug.

(4) Evacuate and charge system with R-22 refrigerant (paragraph 4-10).

(5) Restore electrical power and run air conditioned to check for proper operation.

(6) Remove "Out of Service" tag from circuit.

h. Replace moisture indicator (1, FIGURE 4-11) as follows:

WARNING

PRESSURIZED GAS HAZARD. Make sure the system has been pumped down

and lines purged of residual refrigerant charge (Item 10, Table 4-1).

(1) Remove moisture indicator (1, FIGURE 4-11) by disconnecting fittings (2) and (3).

(2) Install new moisture indicator (1) by connecting fittings (3) and (2).

4-39