4. Apply high temperature thread sealant to bellows
retainer threads. Place bellows (key 9) in body and
secure in place by installing the bellows retainer
(key 8) (see Table 6 for torque values).
5. Use new diaphragm gasket (key 18) and put two
diaphragms (key 10) in place on the body with raised,
preformed centers toward spring case.
6. Stack the lower spring seat (key 11), spring (key 12),
and upper spring seat (key 13) on the diaphragm and
install the spring case. Note that on the low-pressure
pilot, the lower spring seat and diaphragm plate are
part of a subassembly.
7. Lubricate and replace casing cap screws (key 17).
8. Mount pilot on main valve and install all tubing.
To Clean Pilot Strainer Assembly
Remove the valve plug guide (key 2). The valve plug
(key 4), the valve plug spring (key 3) and the strainer
screen (key 77) will come out with the guide. Inspect
and clean or replace as required. Key numbers are
referenced in Figure 9 or 10.
To Clean Bleed Fitting
If the 5/64 in. / 2.0 mm diameter hole in the bleed
fitting (key 61) becomes plugged, it can be cleared by
running a wire through it. To gain access to this hole,
first isolate the valve and relieve all pressure. Then
remove either the tubing and fitting or the pipe plug
from the top of the diaphragm case. Clear the hole,
replace the case fitting and resume normal operation.
Key numbers are referenced in Figure 8.
Figure 6.
Typical Type 92B Construction
PIPE PLUG OR TUBE FITTING –
DIRECTLY OVER ORIFICE
FOR EASE OF ACCESSIBILITY
BLEED ORIFICE –
EASILY CLEANED WITH WIRE
VALVE BODY
DIAPHRAGMS
AND DIAPHRAGM PLATE
DIAPHRAGM CASE
GUIDE
BUSHING
PILOT SPRING CASE
PILOT PRESSURE
SETTING SPRING
BELLOWS AND
BELLOWS
RETAINER
LOWER SPRING SEAT
ORIFICE
CHECK VALVE ASSEMBLY
PILOT VALVE STEM
AND PLUG
VALVE STEM GUIDE
PILOT VALVE SPRING
BOTTOM FLANGE
REDUCING VALVE SPRING
VALVE PLUG AND
SEAT RING
W1322-3A
11
Type 92B