Combustion Air Pressure Switch Maintenance; Suggested Design For Seal Plate, Plugs And Caps For Combustion Tube Leakage Test - Piper Navajo Chieftain PA-31-350 Service Manual

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NAVAJO CHIEFTAIN SERVICE MANUAL
WING NUT
FLAT WASHER
RUBBER STOPPER
DRILL FOR BOLT
FLAT WASHER
BOLT
EXPANSION PLUG
420
DIA.
.19 DIA. HOLES
(6 EQUALLY SPACED)
.125 THICK STOCK
COMBUSTION HEAD OPENING
RUBBER STOPPER
DRILL OUT TO
NECESSARY DIA
CLAMP
SEAL CAP
C
1/8" THICK STOCK
0.180 DIA.
NOZZLE OPENING COVER PLATE
Figure 13-14. Suggested Design for Seal Plate, Plugs and Caps for Combustion Tube Leakage Test
13-35. COMBUSTION AIR PRESSURE SWITCH. (Refer to Figure 13-17.)
a. Removal.
1. Disconnect the electrical leads from the terminals of the combustion air pressure switch
item(17). (Identify leads to facilitate reinstallation.)
2.
Disconnect the tube assemblies from the switch. (Identify tube connections to facilitate
reinstallation.)
CAUTION
Exercise caution not to exert excessive bending of the tubes
during removal and installation procedure.
3. Unscrew and remove the combustion air pressure switch from the fitting on the combustion
air inlet tube.
b. Installation.
1. Install the combustion air pressure switch (17) by rotating it on the threaded fitting of the
combustion air inlet tube and tighten it securely. Exercise caution not to overtorque the switch as this
could change the setting.
2. Connect the tube assemblies to the switch using a suitable thread lubricant.
3. Connect the electrical leads to the appropriate switch terminals. If in doubt regarding proper
connections, refer to the wiring diagram, Figure 13-6.
4. Check for proper heater operation.
Revised: 10/15/82
HEATING AND VENTILATING SYSTEM
4C5