Masoneilan 536V Back Pressure Microflow Regulators Instruction Manual | 6
Copyright 2021 Baker Hughes Company. All rights reserved.
• Carefully apply Never Seez grease (or equivalent) to threads
and bottom of retainer (4). With a 9/16" or 14 mm piece of
hex stock and a wrench, torque the retainer to 59 ft-lbs (8
daN.m) if a graphite gasket st. st. reinforced, or to 40 ft-lbs
(5,5 daN.m) if a glass filled PTFE gasket (See Figure 4).
Note: On regulator with Cv 3.8 torque the retainer to 15
ft-lb (2 daN.m).
• Insert the plug-stem (12 or 183) into the seat ring (3). For a
Cv < 0.10, ensure that there is no binding during the stroking
of the plug. If binding occurs, loosen the retainer (4) and
replace the seat ring (3e) in the correct position until the stem
smoothly slides.
Note: This operation will be facilitated turning the plug by
means of a wrench applied on the nuts (27) tightened one
against the other. Carefully avoid that seating surface of
the plug contacts the seat ring during the plug screwing.
Pulling down motion of the actuator and plug stem screw-
ing must be simultaneously performed: carry on until the
lower part of actuator yoke contacts the body flange (13).
• Place actuator in correct orientation in relation to regulator
body S/A: the 1/2” NPT connection must be 90 degrees apart
from controlled pressure line.
• Screw and tighten the two screws (16). Tighten also the two
nuts (8a). Finger tight the two packing flange nuts (8b).
• Turn the nuts (27) to unscrew plug stem until the seating area
of the plug just contacts the seat ring.
• Admit on actuator diaphragm a supply pressure higher than
setting point value.
• Turn nuts (27) to unscrew plug stem by one turn and a half.
Loosen the two nuts (27) and screw the upper nut against the
coupling (101). During this step, the coupling must be held by
means of a 14 mm flat spanner or pliers. Tighten second nut (27)
against the first, using the two 17 mm flat spanners. Shut off air
supply and disconnect temporary air line from the actuator.
• Connect the controlled pressure line to diaphragm case.
• Place back in service and tighten the nuts (8b) only as much
as is necessary to stop any leakage.
Packing box
Adding Packings
To add a ring of packing, depressurize the regulator, back off
packing flange nuts (8b) all the way, lift the pac-king flange and
follower and insert one ring of packing. Tighten nuts (8b) finger
tight plus one full turn.
Packing Quick Change Method
(For regulators Cv 0.6 to 3.8 only)
The fastest and simplest way to replace packing is to remove the
entire actuator without disturbing actuator parts or calibration.
However, this is not recommended for regulators with a small
Cv (Cv < 0.6), due to the very fineness of their plug. In this
event, disassemble the regulator to replace the packing (See
under “Disassembly”, page 3).
• Remove safety pin (11) from body. The safety pin engages
the packing spacer (5). The function of safety pin and spacer
is to prevent the plug from being pushed out if the actuator is
removed while the regula-tor is still pressurized. The regulator
internal parts can-not be removed unless the safety pin is
removed first. Remove two packing flange nuts (8b) and two
mounting nuts (8a). Remove also two mounting screws (16).
• Remove the actuator-plug assembly off the regulator.
• Clean the packing box and plug stem and carefully place new
rings of packing around the stem. Position the skive cut of
each packing ring 120˚ from that of the adjacent ring.
• Slide spacer (5) aligning the hole in the spacer with the safety
pin (11) hole in the valve body.
Note: For a Cv smaller than 0.10, ensure that the retaining ring
(182) is placed on the plug before engaging it in the spacer
(3f). If the retaining ring is damaged, replace it.
• Wrap the safety pin (11) with two turns of PTFE tape (Teflon).
Screw it into the bonnet five and a half to six turns from where
threads engagement starts.
Note: To find start of threads engagement, proceed as follows:
a. Screw safety pin about one turn,
b. Pull safety pin outwards while unscrewing it.
• Install packing, positioning the skive cut of each packing ring
120˚ away from the cut of an adjacent ring. Slightly push down
rings one after another using a tube 1/2” schedule 160 size.
Install packing follower (9) on the plug stem.
• Insure that any pressure is admitted on diaphragm case. Hold
actuator above body S/A. Before that coupling (101) contacts
the plug stem, screw two nuts (8a) on the two studs (7), slide
packing flange (10) on the plug stem and studs then screw the
two nuts (27) to the threaded end of plug stem. Tighten nuts
one against the other in this position
• While holding the plug in “Open” position (as far as possible),
slowly pull down the actuator and screw the plug stem as long
as possible into the coupling (101).
Figure 4 - Thightening
the seat ring retainer (4)
Regulator must be isolated and pressure vented
before disassembly.
