37
4.12.4 Replacing Valve Internal Parts
Do not damage or over tighten the enclosing tube
assembly. Lubricate and Place all parts in the en-
closing tube in proper sequence to avoid premature
valve failure
a.
Remove the refrigerant charge.
b.
Remove coil snap cap, voltage cover and
coil assembly. Remove the enclosing
tube.
c.
Check for foreign material in valve body.
d.
Clean valve body and enclosing tube
e.
Always put refrigerant oil on O-rings
before installing.
f.
Replace all internal components in order
g.
Tighten enclosing tube.
h.
Install coil assembly, voltage cover and
snap cap.
i.
Evacuate, dehydrate and recharge unit.
j.
Start unit and check operation.
4.13 BRAZING PROCEDURES
Always make sure you are in a ventilated area. The
gases produced by brazing can be harmful Make sure
all refrigerant is removed. Open flame and refrigerant
make a gas called PHOSGENE and can be FATAL.
Take extra precaution with open flame from the
torch. This can cause severe burns.
To ensure a clean braze make sure any contaminants
are remove from the materials. Use a flux according
to the type of braze you are using.
Note:
Most common brazing alloy is 15% PhosCopper
Brazing Alloy along with hard flux
Scotch pads and Oxide sanding paper will ensure you clean
corrosion and burs from the metal
Protect nearby items such as wiring harnesses plastics and
other components of the refrigeration system. Using a
small piece of metal to cover immovable objects may
protect it from the heat of brazing.
Use a heatsink for nearby valves or other joints that you
do not wish to compromise. Special heatsinks designed for
exact diameter tubing can be used. For Items like valves
and in tight areas. A wet rag wrapped tightly around the
valve or joint will protect it. You can also use a heat
absorbing Gel spray.
Figure 19 - Brazing Example
Do not allow the center flame to touch the piping when
brazing. It is very hot and will weaken or melt holes into
the metal.
When heating the pipe joint. Move slowly around to evenly
distribute the heat. Use the flux as a guide. Once the flux
stops bubbling and becomes quiet, it may be time to apply
the brazing alloy.
Feed the alloy into the joint between the tube and fitting
or valve. The alloy should melt and slowly and flow with
the torch flame path. As the melted alloy will follow the
heat of the flame.
