Service Valves; Aluminum Tubing Torque - Piper Dakota Maintenance Manual

A very strong acid (HCL) is formed when Freon comes in contact
with moisture.
Replace any receiver-dehydrator assembly which has been
operated after air has leaked into system. The drying compound
is damaged by moisture contained in air.
New receiver-dehydrators must only be opened and connected to
system when system is ready to be charged
For recommended torque values for flare fittings and O-ring
joints, see chart 2104.
Metal Tube
OD
1/4
3/8
1/2
5/8
3/4

SERVICE VALVES

The purpose of the service valve is to service the air conditioning (testing, bleeding, evacuating, and
c h a rging). This aircraft is equiped with service valves mounted in the suction and discharge lines of the
evaporator assembly. These valves are 2-position Schrader valves. All normal air conditioning service should
be performed at the evaporator assembly mounted valves.
Service valves are also located on the compressor. However, use
of these valves in servicing is not recommended
If a Schrader service valve is not serviceable, core assembly must
be replaced.
PIPER AIRCRAFT
PA-28-236
MAINTENANCE MANUAL
—WARNING—
—CAUTION—
—CAUTION—
—NOTE—
CHART 2104. ALUMINUM TUBING TORQUE
Thread and Fitting
Size
7/16
5/8
3/4
7/8
1-1/16
—NOTE—
—NOTE—
1G4
Alum, Tubing
Torque
5-7 ft lbs
11-13 ft lbs
15-20 ft lbs
21-27 ft lbs
28-33 ft lbs
21 - 52 - 00
Page - 21 - 14
Reissued: August 1, 1986