150-458-100-05
Appendix B - Technical Reference
HRE-458 List 1, List 1B, and List 2
February 23, 2000
35
V
ALVE
R
EPLACEMENT
P
ROCEDURES
All but the Air Stem/Air Intake T-valve shown in
can be replaced, if needed. Order the valve
replacement kit #132-1038-01 listed in
to obtain new valves. Use the following procedures
when replacing any of the four replaceable valves.
Pressure Relief Valve
The pressure relief valve (PRV) is part of an all-metal, nickel-plated brass assembly as shown in
. The valve acts as a guard against excessive pressure on the enclosure and releases the internal pressure
when it exceeds a nominal level of 15 PSI. The assembly consists of an adapter that screws into a brass fitting,
located in the bottom of the baseplate, and the PRV valve itself which screws into this adapter. The adapter has
two O-rings that are required to create an airtight seal. One is located on its outer threaded stem that connects to
the brass fitting; the other is located at the base of its inner well where it seals the PRV to the adapter.
To remove and replace the PRV, proceed as follows:
1
Grip the adapter nut with a
3
/
4
” wrench and the PRV with a
1
/
2
” wrench.
2
While holding the adapter nut steady (it should not be moved), loosen the PRV by turning it
counterclockwise, then remove it by hand. If the adapter nut becomes loose, tighten it to a torque of 60
inch-pounds.
3
Check that the O-ring in the adapter’s inner well has remained in place. If not, reseat it.
4
Thread the new PRV into the adapter. Do not crossthread.
5
Again grip the adapter nut with a
3
/
4
” wrench and the PRV with a
1
/
2
” wrench. Tighten the PRV to a torque
of 120 inch-pounds.
Qty 1
Security Cover
132-1014-01
Metal Locking Clamp, O-Ring, Desiccant
Qty 1
Dome Cover O-Ring
Qty 1
V-Band Locking Clamp
Qty 2
Desiccant (2-unit bag)
132-1038-01
Valve Kit
Qty 2
Pressure Release Valves
Qty 2
Breather Valves
Qty 2
Air Stem Valves
Qty 2
External Pressure Cutoff Valves
Qty 2
Air Intake T-Valve Caps
Qty 2
Desiccant (2-unit bag)
132-1016-01
Hardware Installation Kit
Qty 4
1-inch long,
3
/
8
-inch mounting bolts
Qty 4
3
/
8
-inch mounting nuts
Qty 4
3
/
8
-inch mounting washers
Qty 4
4-inch mounting lug bolts
Qty 2
Desiccant (2-unit bag)
132-1030-01
Protector Tube Kit
Qty 25
47BT Gas Tube Protectors or equivalent
Table 7.
Replacement Part Kits (Cont.)
Number
Part
