| SERVICE PORT |
|
STEM | W/SCHRADER | FIELD |
| CORE | |
|
| SIDE |
|
| STEM |
|
| SERVICE PORT |
|
| W/SCHRADER CORE |
| FIELD |
|
| SIDE |
|
SEAT |
|
|
|
| SEAT |
BAR STOCK FRONT SEATING VALVE
FORGED FRONT SEATING VALVE
A91447
A91448
Fig. 44—Service Valves
b. Remove all flux residue with brush and water while material is still hot.
2.Use ″
3.Silver solder is used on
4.Fluxes should be used carefully. Avoid excessive applica- tion and do not allow fluxes to enter into the system.
5.Proper brazing temperature of copper is when it is heated to a dull red color.
This section on brazing is not intended to teach a technician how to braze. There are books and classes that teach and refine brazing techniques. The basic points above are listed only as a reminder.
IV. SERVICE VALVES
WARNING: Never attempt to make repairs to existing service valves. Unit operates under high pressure. Dam- aged seats and
Service valves provide a means for holding original factory charge in outdoor unit prior to hookup to indoor coil. They also contain gage ports for measuring system pressures and provide shutoff convenience for certain types of repairs. (See Fig. 44.)
Two types of service valves are used in outdoor residential equipment. The first type is a
The second type is a combination
pressurized. To pressurize the service port, this valve must be moved off the
The service valves in the outdoor unit come from the factory
Before brazing the line set to the valves, the belled ends of the sweat connections on the service valves must be cleaned so that no brass plating remains on either the inside or outside of the bell joint. To prevent damage to the valve and/or cap ″ O″ ring, use a wet cloth or other acceptable
After the brazing operation and the refrigerant tubing and evapo- rator coil have been evacuated, the valve stem can be turned counterclockwise until it opens or
The service valve cannot be