ADC 150-2204-01, Руководство пользователя

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Appendix B: Additional Information 150-506-100-03
42 March 28, 2000 HRE-506 List 1 and List 2
Replacing the Air Stem Valve
The Air Stem Valve (ASV) is part of an all metal, nickel plated brass assembly, as shown in Figure 2 on page 3 .
It is used to pressurize the enclosure from an external air supply or release the internal pressure.
The assembly consists of an adapter that screws into a brass fitting located at the bottom of the base. The ASV
itself, which screws into this adapter and the cap connects to the top of the ASV. 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 ASV to the adapter. See
To remove and replace the ASV, proceed as follows:
1 Grip the adapter nut with a
3
/
4
-inch wrench and the ASV with a
7
/
16
-inch wrench.
2 While holding the adapter nut steady (it should not be moved), loosen the ASV by turning it counterclockwise
and then remove the valve 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 adapters inner well has remained in place. If not, reseat it.
4 Thread the new ASV into the adapter. Do not crossthread.
5 Grip the adapter nut with a
3
/
4
-inch wrench and the PRV with a
7
/
16
-inch wrench and tighten the latter to 120
inch-pounds of torque.
6 Pressurize the chamber and check entire assembly for leaks.
Do not overtighten. Excessive torque does not improve the seal and may damage the valve.
Do not overtighten. Excessive torque does not improve the seal and may damage the ASV.
This same ASV is also used in the Air Stem/Air Inlet T-valve assembly. The ASV in the T
assembly can also be replaced. However, the rest of the T assembly is not replaceable.