Assembly Of Crossfeed Valve; Leak Test Of Crossfeed Valve; Cleaning, Inspectoin And Repair Of Fire Wall Shutoff Valve; Leak Test Of Fire Wall Shutoff Valve - Piper Navajo Chieftain PA-31-350 Service Manual

NAVAJO CHIEFTAIN SERVICE MANUAL
NOTE
Fitting (4) in valve is special. Do not use AN fittings.
9-23. ASSEMBLY OF CROSSFEED VALVE. (Refer to Figure 9-7.)
a.
If seat valve (4) was removed, install the O-ring packing (6) and assemble the seat fitting on the
valve body (3).
b.
Lubricate the O-ring packings with a thin coat of stop-lock grease and install.
c.
Push the stem (2) into tne valve.
d.
Connect the control arm (10) with the stem and secure with pin (8) and nut (9).
e.
Check valve operation.
9-24. LEAK TEST OF CROSSFEED VALVE.
a.
Connect one port of the valve to a 50 psig air source.
b.
Close valve, apply pressure to 50 psig and submerge in kerosene or a similar petroleum base fluid
for two minutes.
c.
Depressurize and connect the air source to the other port of the valve.
d.
Repeat step b.
e.
There shall be no evidence of leaking through the valve seat or around the valve stem.
f.
Disconnect and wipe fluid from exterior.
9-25. DISASSEMBLY OF FIRE WALL SHUTOFF VALVE. (Refer to Figure 9-8.)
a.
Remove the snap ring (3) on the bottom of the valve.
b.
Push the valve (2) from the valve body (1).
c.
Remove and discard the O-rings (7 and 8).
9-26. CLEANING, INSPECTION AND REPAIR OF FIRE WALL SHUTOFF VALVE.
a.
Clean the valve components in a suitable cleaning solvent.
b.
Inspect the valve for the following:
1.
Check that the valve and valve body stop pins are not bent, broken or missing.
2.
Check that the handle is not loose on the valve.
3.
Check that the valve and inside of the valve body is free of scratches, burrs, etc., that may
damage the O-rings.
c.
Repair to the valve is limited to reconditioning of parts, such as smoothing out minor nicks and
scratches, and replacing of O-rings.
9-27. ASSEMBLY OF FIREWALL SHUTOFF VALVE. (Refer to Figure 9-8.)
a.
Ascertain that the snap ring (6) is installed on the upper portion of the valve (2).
b.
Place new O-rings (7 and 8) on the valve.
c.
Lubricate the O-rings with DC-55 (MIL-G-4343) and insert the valve (2) in the valve body (1).
Place the valve so that the valve is allowed only 90°travel between stops.
d.
Lock the valve in the valve body by installing the snap ring (3) on the valve.
9-28. LEAK TEST OF FIRE WALL SHUTOFF VALVE.
a.
Connect the inlet port of the valve to a 50 psig air source.
b.
Close valve, apply pressure to 50 psig and submerge in kerosene or similar petroleum base fluid
for two minutes.
c.
There should be no evidence of leakage through the valve port or around seat.
d.
Disconnect and wipe fluid from exterior.
Reissued 9/23/80
FUEL SYSTEM
Reissued: 9/23/80
2K18