Test Setup For Fuel Regulator And Shutoff Valve - Piper Navajo PA-31 Service Manual

GAGE
GAGE
REGULATOR
FUEL FLOW
SUPPLY
REGULATOR
FUEL
NOZZLE
ELECTRICAL
POWER SUPPLY
Figure 13-23. Test Setup for Fuel Regulator and Shutoff Valve
13-37. FUEL REGULATOR AND SHUTOFF VALVE. (Refer to Figure 13-30, 13-31 or 13-32.)
a. Removal:
1. Disconnect the electrical lead from the valve.
2. Disconnect the fuel lines from the inlet openings. Make note of these connections for
correct installation.
3. Remove the two attaching screws to free the unit from its mounting.
b. Adjustment: The fuel regulator and shutoff valve used in this system are adjustable but not
repairable. The following steps cover the proper adjustment of this unit:
1. Install the regulator in a test stand similar to that shown in Figure 13-23.
2. Install a 2.0 gph nozzle (Janitrol Part No. C08D09). Gasoline or Stoddard solvent can be
used for testing.
3. Apply a fluid pressure of 20 to 30 psi and energize the solenoid.
4.
Using a screwdriver, break the adjustment seal and adjust the regulated outlet pressure as
close to 7.5 psi as possible. (Turn clockwise to increase pressure; counterclockwise to decrease pressure.)
5. Slowly vary the inlet pressure from 10 to 50 psi. The outlet pressure should remain between
7.0 to 8.0 psi.
6.
With the inlet pressure of 50 ± 3 psi de-energize and energize the solenoid at least twice. The
outlet pressure should be 7.0 to 8.0 psi with solenoid energized and when the solenoid is de-energized the
pressure should drop to zero and the fuel flow from the nozzle should stop.
7. With solenoid energized, slowly reduce inlet pressure from 50 to 10 psi. Outlet pressure
should remain between 7.0 and 8.0 psi.
8. During the above tests, observe for signs of external leakage. Any leakage is cause for
rejection of the regulator. After satisfactory adjustment has been made, apply Glyptol around threads of
the adjustment screw and in the slot.
c. Installation:
1.
Attach the fuel regulator and shutoff valve to its mounting with the two attaching screws.
2. Place the fuel regulator and shutoff valve into position between the fuel line connections
and install. Tighten all connections securely.
3.
Connect the electrical lead. Be sure to slide an insulating sleeve (or tape) over the
connection to avoid a short circuit and secure sleeve in place.
4. Operate the heater to make sure the unit is functioning properly.
Reissued: 10/12/79
HEATING AND VENTILATING SYSTEM
PIPER NAVAJO SERVICE MANUAL
5C6