Masoneilan 173 Series Pressure Regulator Instruction Manual | 9
© 2016 General Electric Company. All rights reserved.
4.5.2 Disassembly
Disassembling and reassembling operations for all types of
173-50 regulators as long as the diaphragms are considered.
These are:
- 1 single elastomeric diaphragm for 173-50 single diaphragm
regulators;
- 2 elastomeric diaphragms (one per side) for 173-50 double
diaphragm regulators.
Make sure the spares match the above and take great care
when mounting the diaphragm assembly.
4.5.2.1 Actuator Disassembly
Release the spring compression by turning the adjustment
screw counterclockwise, counting and noting the number of
turns in order to restore calibration after reassembly. Remove
the spring housing (9) by loosening the nuts (21). It is not
necessary to remove the housings of the 220 and 360 actuators.
Remove the spring.
- For single diaphragm regulators: unscrew the nut (11) and
remove the diaphragm with the diaphragm plate (6) and
spring guide (19). (See Figure 9)
- For double diaphragm regulators: unscrew the lock nut (11)
and nut (29) and remove the double diaphragm assembly
with ring (30), intermediate plate (31), diaphragm plate (6) and
spring guide (19). (See Figure 10)
4.5.2.2 Body Disassembly
Unscrew and remove the cover with relevant gasket. Unscrew
the seat with a screwdriver. (See Figures 9 and 10)
Pull the plug off its guide and remove it from the body.
4.5.3 Parts Inspection
(Refer to Figures 9 and 10)
All of the components are now ready to be inspected. Replace
any worn items. Clean all parts.
Pay particular attention to the condition of the disc of the plug
(24), both elastomeric and metal, and the seat.
If the seat is worn, it may be able to be restored by lapping using
a metal disc and abrasive paste.
The diaphragm should be replaced if it shows any damage. The
same applies to the Teflon diaphragm protector (if included).
Gaskets should not be reused.
If preferred, the regulator may be returned to an authorized GE
repair center to be reconditioned.
4.5.4 Reassembly
Carry out the disassembly operations in reverse order. Push the
stem of the plug into its guide and tighten the seat (26). Screw
the cover (1) back on. Install the diaphragm/s (see section 4.5)
taking care to properly arrange the Teflon protectors. Make sure
the seats of the O-rings are perfectly clean before mounting
them. Assemble:
- For single diaphragm regulators: plug assembly, diaphragm
plate, diaphragm and spring guide (with gaskets), and nut.
- For double diaphragm regulators: plug assembly, diaphragm
plate, lower diaphragm, intermediate plate and actuator ring,
upper diaphragm, spring guide (with gaskets), nut and lock nut.
Match the holes of the diaphragm/s with the holes in the
actuator flange and install the spring, spring holder and housing.
Turn the adjustment screw the number of turns noted during
dismounting. Exact calibration must then be checked when the
regulator is placed back into service.
4.5.5 Replacing the Diaphragm
The diaphragm may require replacement without having to
make other repairs. If the regulator is easy to access and
isolate, it can be replaced while leaving the regulator installed
in the piping. In this case, isolate the regulator and vent all
pressure. To prevent accidental pressurization while working
on the regulator, make sure that the isolation valves are locked.
Remove the actuator following the instructions in section 4.5.2.
Replace and install the diaphragm and reassemble
the actuator as shown in section 4.5, 4.5.3 and 4.5.6. Check
calibration once more when the regulator is returned
to service.
