Special Servicing Procedures; General Refrigeration System Procedures - Piper PA-32R-301 SARATOGA SP Maintenance Manual

COOLING (cont.)
E. Special Servicing Procedures
The air conditioning system should be serviced by a qualified shop with trained personnel. The follow-
ing procedures and precautions should be observed.
The efficiency of this system depends upon the pressure-temperature relationship of pure refrigerant.
As long as the system contains only pure refrigerant plus a specified amount of compressor oil (which
is mixed with the refrigerant), it is considered to be chemically stable. Foreign materials within the
system will affect the chemical stability, contaminate the system, and decrease its efficiency.
F

General Refrigeration System Procedures

(1) Refrigerant Safety Precautions
(a) Refrigerant 12 (commonly known as R-12 (or Freon 12) is odorless and colorless in either
the liquid or gaseous state. R-12 for charging refrigeration systems is supplied in pressur-
ized containers (approx. 70 psi at 70 F in liquid form). Since this material is essentially inert
at room temperatures the dangers are primarily associated with the pressure and the refrigera-
tion effects of the release and subsequent evaporation of this pressurized liquid.
(b) Wear suitable eye protection when handling R-12 due to the possibility of freezing of the eye
if contacted by escaping liquid refrigerant. If liquid R-12 does strike the eye, the following
actions should be taken:
1 DO NOT RUB THE EYE.
2 Splash large quantities of cool water into the eye to raise the temperature.
3 Tape on an eye patch to avoid the possibility of dirt entering the eye.
4 Rush to a physician or hospital for immediate professional aid.
5 DO NOT ATTEMPT TO TREAT IT YOURSELF.
(c) If liquid R-12 strikes the skin frostbite can occur. Treat with cool water and protect with
petroleum jelly.
(d) Do not discharge large quantities of R-12 into closed rooms. It may displace most of the air
in the room and this could cause oxygen starvation. Gaseous R-12 is heavier than air and
flows to the bottom of a container.
(e) Do not discharge R-12 into an open flame or onto a very hot surface (500F). Poisonous phos-
gene gas is generated by the action of the heat on the refrigerant.
(f) Do not apply direct flame or other high heat source to a R-12 container due to the high
pressures which will result. If any heating is done to R-12 containers the container pressure
should be monitored and kept below 150 psi.
(2) System Servicing Precautions
Environmental regulations may require use of a collection
system when necessary to evacuate freon from system
(a) Systems should be discharged slowly to prevent the escape of liquid refrigerant and the loss
of the lubrication oil.
(b) Systems should not be left open to the atmosphere when discharged. Moisture and other con-
tamination may enter and damage open systems.
(c) Never introduce anything but pure refrigerant and refrigerant oil into a system.
PIPER AIRCRAFT
PA-32R-301/301T
MAINTENANCE MANUAL
— CAUTION —
1I1
21-50-00
Page 21-18
Reissued: July 1, 1993