Trane 4TWX6048B D. Service Valve Operation, GAS LiNE SERVICE VALVE, Brazing Refrigerant Lines

©	GAS LiNE SERVICE VALVE
	CAP _	_	1/4 TURN	ONLY
			COUNTERCLOCKWISE
			FOR FULL	OPEN
		I	.... POSITION
	OF VALVE
	........ F"_		STE"
	PRESSURETAP PORT		J
	GAS	LINE	CONNECTION

CAP_

D. SERVICE VALVE OPERATION

BRASS LIQUID LINE SERVICE VALVE

The Brass Liquid Line Service Valve is factory shipped in the seated position to hold factory charge. The pressure tap service port (when depressed) opens only to the field brazing side of the valve when the valve is in the seated position. The liquid line valve is not a back seating valve (see WARNING below).

Extreme caution should be exercised when opening the Liquid Line Service Valve. Turn valve stem counterclock- wise only until the stem contacts the rolled edge. (See Figure 3) No torque is required.

BRASS GAS LiNE SERVICE VALVE

The Brass Gas Line Service Valve is shipped in the closed

position to hold the factory refrigerant charge. The pressure tap service port (when depressed) opens only to the field

brazing side when the valve is in the closed position.

The Gas Line Service Valve is full open with a 1/4 turn. See

Figure 4.

BRAZING REFRIGERANT LINES

1.Remove lower access cover to access service valves.

2.Before brazing, remove plugs from external copper stub tubes. Clean internal and external surfaces of stub tubes

prior to brazing.

3.Cut and fit tubing, minimizing the use of sharp 90 ° bends.

4.Insulate the entire gas line and its fittings.

5.Do NOT allow uninsulated liquid line to come in direct contact with bare gas line.

6.Precautions should be taken to avoid heat damage

to the pressure tap valve core during brazing. It is

recommended that the pressure tap port valve

core be removed and a wet rag wrapped around the valve body.

NOTICE:

Use care to make sure that no moisture enters pressure tap port, while wet rag is being used.

NOTICE:

Precautions should be taken to avoid heat damage to basepan during brazing. It is recommended to keep the flame directly off of the basepan.

18-BC55D1-2

nstaer's Guide

7.Use a Dry Nitrogen Purge and Brazing Alloy without flux when brazing the field line to the copper factory connection. Flow dry nitrogen into either valve pressure tap port, thru the tubing and out the other port while brazing.

8.Braze using accepted good brazing techniques.

LEAK CHECK

IMPORTANT:

Replace pressure tap port valve core before attaching hoses for evacuation.

After the brazing operation of refrigerant lines to both the outdoor and indoor unit is completed, the field brazed

connections must be checked for leaks. Pressurize through the service valve ports, the indoor unit and field refrigerant lines with dry nitrogen to 350-400 psi. Use soap bubbles or

other leak-checking methods to see that all field joints are

leak-free! If not, release pressure; then repair!

SYSTEM EVACUATION

NOTE:

Since the outdoor unit has a refrigerant charge, the gas and liquid line valves must remain closed.

1.Upon completion of leak check, evacuate the refrigerant lines and indoor coil before opening the gas and liquid line valves.

2.Attach appropriate hoses from manifold gauge to gas and liquid line pressure taps.

NOTE:

Unnecessary switching of hoses can be avoided and com- plete evacuation of all lines leading to sealed system can

be accomplished with manifold center hose and connect- ing branch hose to a cylinder of R-410A and vacuum pump.

3.Attach center hose of manifold gauges to vacuum pump.

4.Evacuate until the micron gauge reads no higher than 350 microns.

5, Close off valve to vacuum pump and observe the micron gauge. If gauge pressure rises above 500 microns in

one (1) minute, then evacuation is incomplete or system has a leak.

6.If vacuum gauge does not rise above 500 microns in one (1) minute, the evacuation should be complete.

7.With vacuum pump and micron gauge blanked off; open

valve on R-410A cylinder and charge refrigerant lines and indoor coil with vapor to tank pressure of R-410A supply.

NOTE:

DO NOT VENT REFRIGERANT INTO THE ATMOSPHERE.

8.Close valve on R-410A supply cylinder. Close valves on

manifold gauge set and remove refrigerant charging hoses from liquid and gas pressure tap ports.

NOTE:

A 3/16" Allen wrench is required to open liquM line service valve. A 1/4" Open End or Adjustable wrench is required to open gas line valve. A 3/4" Open End wrench is required to take off the valve stem cap.

9.The liquid line shut-offvalve can now be opened. Remove

shut-offvalve cap. Fully insert hex wrench into the stem

and backout counterclockwise until valve stem just

touches rolled edge (approximately five [5] turns)

observing WARNING statement on page 2. See Figure 3.