18 | Baker Hughes
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Figure 26
Insert Body Insert (Cartridge) with lubricated Stem O-Ring
into the Pilot Body
ATTENTION: Over tightening an O-Ring Joint will not
improve the seal. Screw in until metal parts make contact
and snug slightly.
Stainless
Steel/Plug
Stem
Delrin Orifice
Figure 27
Delrin Orifice and Stainless Steel Plug/Stem assembly in
the Back Pressure mode. The white Delrin material distin-
guishes itself from the standard stainless steel orifice
Hydrostatic Testing
All Mooney Series 20 Relief Valves are hydrostatically tested prior
to shipment according to ISA-S75.19.01-2013. If it is necessary
to retest the valve, use the following procedure:
1. Disconnect and remove all control line(s) and the pilot from
the main valve.
2. Tube (A) the inlet neck NPT port (C) with the dome NPT port
(B) so that they are common. (Figure 28)
3. Plug the outlet NPT port (D).
4. Increase pressure slowly so the pressure has a chance
to stay equalized in both the inlet and dome chambers.
(Smallest restriction is about 3/16” DIA.)
5. Maximum valve hydrostatic pressure for each class:
a. 150CL: 450 psi
b. 300CL: 1125 psi
6. After hydrostatic test is completed, follow the disassembly,
cleaning, and assembly procedures in the respective
Maintenance Manuals.
WARNING: Maximum Valve Hydrostatic Pressure is not the
same as Line Hydrostatic Pressure
Figure 28
Accessories
Manual or Remote Blowdown Valve
Blowdown valves allow bleeding of the dome pressure manually
by hand (ball valve) or by electronic signal (solenoid). This action
overrides the pilot until the blowdown valve is closed again. The
pilot then regains control of the system and responds according
to system conditions.
Pressure Differential Switch
A pressure differential switch is available which may be wired to
an operator station or some other remote location. The switch will
provide a signal that indicates when the main valve is opening.
