ADC 150-2202-01, Руководство пользователя

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150-504-100-03 Appendix A - Technical Reference
HRE-504 List 1, List 1B, and List 2 August 1, 2002 39
V
ALVE
R
EPLACEMENT
P
ROCEDURES
All four of the metal valves shown in Figure 2 on page 3 can be replaced if needed. Order the valve replacement
kit #132-xxxx-01 listed in Table 5 to obtain new valves. Use the following procedures when replacing any of the
four valves.
Pressure Relief Valve
The pressure relief valve (PRV) is part of an all metal, nickel-plated brass assembly as shown in Figure 2 on
page 3 . The valve acts as a guard against overpressurizing the enclosure and releases the internal pressure when
it exceeds a nominal level of 15 PSI.
The assembly consists of an adapter that tightens into a brass fitting (located on the bottom of the baseplate), and
the PRV valve which tightens into this adapter. The adapter has two O rings 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:
1 Grip the adapter nut with a
3
/
4
-inch (1.9 cm) wrench and the PRV with a
1
/
2
-inch (1.3 cm) wrench.
2 While holding the adapter nut steady, loosen and remove the PRV by turning it counterclockwise. If the
adapter nut becomes loose, tighten it to 60 inch-pounds.
3 Verify that the O ring in the adaptor’s inner well has remained in place. If not, reseat it.
4 Thread the new PRV into the adapter. Do not crossthread.
5 Grip the adapter nut with the
3
/
4
-inch (1.9 cm) wrench and the PRV with a
1
/
2
-inch (1.3 cm) wrench and torque
the latter to 120 inch-pounds. Do not overtighten. Excessive torque does not improve the seal and may
damage the PRV.
6 Pressurize the chamber and check entire assembly for leaks.
Breather Vent Valve
The breather vent valve (BVV) is an all metal, nickel-plated brass unit shown in Figure 2 on page 3 . The valve
allows air to circulate into the enclosure so it can breath and avoid the build up of excessive moisture and other
contaminants.
It has a hollow threaded stem that tightens into a brass fitting (located on the bottom of the baseplate). An O ring
is located on its outer threaded stem that connects to the brass fitting. The hollow stem contains a piece of plastic
screen to prevent insects from entering the enclosure.
To remove and replace the BVV:
1 Grip the BVV with a
3
/
4
-inch (1.9 cm) wrench, and turn it counterclockwise to remove.
2 Verify that the new BVV came equipped with its O ring.
3 Thread the new BVV into the brass fitting. Do not crossthread.
4 Grip the BVV with a
3
/
4
-inch (1.9 cm) wrench and torque to 60 inch-pounds. Do not overtighten. Excessive
torque does not improve the seal and may damage the valve.