Mooney Series 21 Regulator Instruction Manual | 5
Copyright 2021 Baker Hughes Company. All rights reserved.
Maintenance
Regulator parts are subject to normal wear and must be inspected
and replaced as necessary. The frequency of inspection and
replacement of parts depends on severity of service conditions
and/or the requirements of local, state, and federal regulations.
Be certain that the name plates are updated to accurately indicate
any field changes in equipment, materials, service conditions, or
pressure settings.
Before disassembly, make sure the regulator has been
isolated from the process by closing block valves
on the inlet and outlet sides of the regulator. Safely
release pressure and process fluid from the regulator
system. Failure to properly complete these steps may
result in personal injury and property damage.
1. After depressurizing the regulator and main valve, unscrew
and remove Body Insert Assembly.
2. Remove the Stem O-ring from the regulator body using
a suitable tool and being careful no to scratch the O-ring
Groove.
Figure 6
A paper clip easily extracts the O-Ring out
of the regulator body.
Note: A spare Body Insert Assembly may be installed and
the regulator returned to service if time is a factor. Make sure
the Stem O-Ring is in place in the Regulator Body before
installing the new Body Insert Assembly or, if removed, slip
a new O-Ring over the Stem of the Body Insert Assembly
prior to installing it in the Regulator Body.
Regulator Disassembly - All Series 21 Regulators
3. Remove the Bottom Cap from the Body Insert and remove
the internal parts. The Orifice Assembly can be easily
pushed out of the Body Insert using a heavy paper clip or
0.045” (1.14mm) diameter wire. See Figure 7.
Note: Do not scratch or damage the O-Ring sealing
surface of the Body Insert.
4. Inspect all parts for wear or damage.
5. Regulator Diaphragm: Release all Main Spring tension by
unscrewing Adjusting Screw. Remove Closing Cap, Spring
Follower, and Main Spring. Remove Spring Housing Cap
Screws and remove Diaphragm Assembly. Disassemble
Diaphragm Assembly and inspect Diaphragm. Replace if
necessary.
Figure 7
The orifice can be pushed out of the Body Insert
(Cartridge) using a paper clip.
Regulator Assembly - Series 21 & 21S
1. Diaphragm Assembly: Install the Regulator Diaphragm
with convex side toward Diaphragm Plate and Main Spring
(Refer to Figure 8). Tighten nut on the Diaphragm Retainer
to approximately 5 to 6 ft-lbs (6.78 - 8.14 n-m) torque.
Note: Overtightening will distort the Regulator
Diaphragm.
Figure 8
Diaphragm Assembly for the Series 21 & 21S Regulator.
2. Place Diaphragm Assembly in the regulator body with the
diaphragm touching the grooved sealing surface of the
regulator body. (Refer to Figure 9)
Figure 9
Placing Diaphragm Assembly on Regulator Body.
3. Place Spring Housing on Regulator Body with vent
connection in desired position.
Figure 10
Placing the Spring Housing on the Regulator Body.
4. Install Spring Housing Cap Screws. Use cap screws
supplied and tighten evenly to 8 ft-lbs (10.85 Nm) torque.
