Masoneilan 536V Back Pressure Microflow Regulators Instruction Manual | 4
Copyright 2021 Baker Hughes Company. All rights reserved.
Set Point Adjustment
d. By means of two 17 mm flat spanners, unlock the plug
stem nuts (27) and unscrew them to the threaded end of the
plug stem (12 or 183). Tighten nuts one against the other in
this position.
e. Fasten the actuator to a hoisting gear and very slowly pull
out the actuator-plug S/A.
f. With a flat spanner applied on the upper nut (27), unscrew
the plug stem from the coupling (101) while pulling out
actuator vertically and slowly. Carry on until plug stem is fully
unscrewed from coupling.
g. Separate actuator and packing flange (10) from the body
S/A. Shut off temporary supply on actuator.
h. Remove two nuts (27) and packing follower (9) from the
plug stem.
i. Using a packing hook, remove the largest number of
packing rings (6) from packing box. Remove safety pin (11)
and pull plug stem to remove packing spacer (5) and the
remainder of packing rings.
j. Using a 9/16” or 14 mm piece of hex stock and a wrench,
unlock and pull out seat ring retainer (4).
k. Pull out seat ring (3) and gasket (2) using a hook made from
steel wire, diameter about 3 mm. Carefully fettle the hook end.
Note: The seat ring with Cv < 0.10 consists of two parts:
The seat ring proper (3e) and a spacer (3f). The small size
of orifice of these parts does not allow for their removal
by means of a hook. Therefore, it is necessary to remove
the body from the pipe, turn it over and, if needed, to hit
the bottom with a wooden mallet. Should the seat ring be
jammed in its housing, it is possible to move it using a
screwdriver inserted through the outlet orifice. Regulator
with Cv 3.8 does not feature any seat ring gasket (2).
Reassembly and Plug Stem Adjustment
(Figures 3, 5, 6 & 7)
Before reassembly, thoroughly clean the inside of the valve
body and parts. Mating surfaces must be tho-roughly cleaned.
On reassembly, new seat ring gasket (2) and new packing (6)
must be used.
• Place a new seat ring gasket (2) in the valve body (13) and
install the seat ring (3) taking care to correctly center the
gasket on the seat ring shoulder. Orient it in such a manner
that one of its ports lines up with the body outlet orifice.
Note: For a Cv smaller than 0.10, the seat ring (3e) shall first be
positioned on the new gasket (2) taking the same precautions
as shown above. Next, engage spacer (3f) and orient one of
its ports towards the body outlet orifice. Regulator with Cv
3.8 does not feature any seat ring gasket (2).
The regulator pressure range is engraved on the serial plate.
To adjust spring compression (set point), proceed as follows:
• Open stop valve on the outlet side of the regulator and
partially open stop valve on the inlet side, allowing pressure
in the system to build up slowly.
• Open controlled pressure line valve and check setting by means
of the gauge. Set by means of spring adjuster screw (36).
Note: To increase pressure setting, turn adjusting screw
clockwise to compress the spring. To decrease the setting,
turn adjusting screw counterclockwise to relieve spring
compression).
• Fully open stop valve on the inlet side of the regulator.
Maintenance
If there is excessive leakage through the regulator when it is
shut off, the cause may be:
1. Foreign matter holding valve off seat: disassemble and
clean.
2. Normal wear of seatting surfaces: disassemble and replace
plug and/or seat ring.
3. Seat ring gasket (2) damaging (except with trim for Cv max.
3.8): replace gasket.
Part Replacement in Body S/A
Disassembly (Figures 3, 5, 6 & 7)
a. Disconnect the control line at the diaphragm case and
connect a temporary supply air line.
b. Admit on the diaphragm sufficient pressure to open the plug
about 1 mm.
c. Remove the two packing flange nuts (8b). Raise packing
flange (10) up the plug stem and remove the two nuts (8a)
as well as the two mounting screws (16).
Tests have been performed at the factory to check
correct operation of the regulator on its full nominal
spring range. After that, the spring compression has
been fully removed to avoid unnecessary stress of
parts (diaphragm, spring) during storage.
THEREFORE IT IS NECESSARY TO PROCEED WITH
ADJUSTMENT BEFORE SERVICING.
Regulator must be isolated and pres-sure vented
before disassembly.
Carefully avoid that seating surface of the plug
contacts the seat ring during the plug unscrewing.
