Masoneilan 536V Back Pressure Microflow Regulators Instruction Manual | 8
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• Reassemble the actuator-plug assembly to the regula-tor
body, taking care: (a) to align hole in spacer (5) with safety pin
hole ; (b) to replace two mounting nuts (8a) before nuts (8b) ;
(c) to take extra care in guiding each ring into the packing box.
• Tighten two nuts (8a) and two screws (16) on the actuator
yoke.
• 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 in about one turn,
b. Pull safety pin outwards while unscrewing it.
• Replace packing follower, packing flange and flange nuts
(8b). Tighten nuts finger tight plus one full turn. Place back
in service.
Replacing Diaphragm
a� Disconnect the controlled pressure line from actuator case
connection. Remove spring barrel cap (72). By means of
a paint spot, make a mark on the spring adjuster screw
(36) with regard to upper part of spring barrel (71) ; this
is a reference of the service set point, in preparation to
reassembly. Fully unscrew the spring adjuster screw (36) to
remove (or release as far as) the spring compression.
b. Unscrew nuts (46) then remove cap screws (45) and upper
diaphragm case (43) - spring barrel (71) -spring adjuster
(36) subassembly, (as well as spring barrel spacer (102) in
case of ranges 3-15 ; 10-40; 30-85 and 60-170 psi).
c. Remove upper spring seat (33) and spring (22). In case
of ranges 10-40 ; 30-85 and 60-170 psi, remove also the
reducing ring (23).
d. By means of two 1/2” or 13 mm flat spanners, unlock the
upper stem nut (30).
e. By means of a 17 mm flat spanner applied on upper plug
stem nut (27), prevent the rotation of actuator stem (26) and
unscrew the second nut (30).
f. Remove lower spring seat (34). In case of ranges 0,5-3 and
2-5 psi, remove also the diaphragm plate (40).
g. Remove the diaphragm (39). Clean thoroughly all parts in
preparation for reassembly.
h. Place new diaphragm and reassemble by reversing of the
above description order. Adjust spring compression to set
point, proceeding as indicated under “Set Point Adjustment”.
Place back in service.
Replacing O-ring (38)
(Only in case of 0,5-3 psi range)
• Perform steps a. to g. of the above chapter “Replacing
Diaphragm”. Remove diaphragm washer (41) and loosen the
packing nut (20).
• 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.
• By means of a 14 mm flat spanner or pliers, hold the coupling
(101) and, with a 17 mm flat spanner applied on the upper nut
(27), unscrew the plug stem from the coupling. Do not unlock
the coupling nut (47).
• Remove the four screws (18) and together raise the actuator
packing box (31), packing box parts (32-20), O-ring (38) and
actuator stem (26).
• Remove O-ring (38) from its box. Carefully clean all parts.
• Place a new O-ring, then place the packing box subassembly,
using the four cap screws (18). Insure that orientation and
centering of the lower diaphragm case (44) are correctly
achieved.
• Screw the actuator stem and coupling (26-101) as far as
possible on the plug stem. (Do not overtighten).
• Place diaphragm washer (41), diaphragm, diaphragm plate
(40), lower spring seat (34) then, finger tight one of the two
nuts (30) on the actuator stem end (26).
• By means of a 14 mm flat spanner or pliers, applied on the
coupling (101), hold actuator stem (26) and firmly tight nut
(30). With two 1/2” or 13 mm flat spanners tighten second nut
(30) against the first.
• Place spring (22), its upper spring seat (33) and upper
diaphragm case (43) - spring barrel (71) -spring adjuster (36)
subassembly, with screws (45) and nuts (46). Tighten actuator
packing nut (20).
• Turn spring adjuster screw (36) until the paint mark previously
performed flushs with the upper part of the spring barrel.
• Connect a temporary supply air line on the lower diaphragm
case connection (44).
• 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.
Unlock 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.
Adjust the set point, proceeding as indicated under “Set Point
Adjustment”. Place back in service.
Regulator must be isolated and pressure vented
before disassembly.
In case of ranges 3-15 ; 10- 40 ; 30-85 and 60-170
psi, the spring is always under light compression
after fully unscrewing of spring adjuster (36). So,
prior removal upper diaphragm case and spring
barrel subassembly, the nuts (46) — located above
diaphragm case in these configurations — must be
evenly and progressively unscrewed until spring
compression is fully relieved.
