Trane 4TWA3 manual GAS Line Ball Service Valve, GAS Line Service Valve

4GAS LINE BALL SERVICE VALVE

CAP	1/4 TURN ONLY
	COUNTERCLOCKWISE
	FOR FULL OPEN
	POSITION
	VALVE STEM

UNIT SIDE

OF VALVE

PRESSURE TAP PORT

GAS LINE CONNECTION

5GAS LINE SERVICE VALVE

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).

!WARNING

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 4.) 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 dam- age to the pressure tap valve core during braz- ing. 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.

18-BC62D1-1

Installer’s Guide

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.

7.Use a Dry Nitrogen Purge and Brazing Alloy without flux when brazing the field line to the copper factory connec- tion. 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 units 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 connecting 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.Blank off vacuum pump and micron gauge, close valves on manifold gauge set.

NOTE:

DO NOT VENT REFRIGERANT INTO THE ATMOSPHERE.

NOTE:

A 3/16" Allen wrench is required to open liquid 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.

8.The liquid line shut-off valve can now be opened. Remove shut-off valve cap. Fully insert hex wrench into the stem and backout counterclockwise until valve stem just touches rolled edge (approximately five [5] turns) observ- ing WARNING statement on page 3. See Figure 3.

9.Replace liquid service pressure tap port cap and valve stem cap. These caps MUST BE REPLACED to prevent leaks. Replace valve stem and pressure tap cap finger tight, then tighten an additional 1/6 turn.

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