172-65316M-08 (MB12A/MB12AF/MB12B/MB12BF) 7 Oct 2021
19
Disassembly/Reassembly of the Valve Unit Gland Section
Part
During Disassembly
During Reassembly
Part Inspection
Holder
Screw
Remove with an allen
wrench
If the valve body material is
stainless steel, coat threads with
anti-seize; tighten to the proper
torque
—
Holder
Remove with a socket
wrench
If the valve body material is
stainless steel, coat threads with
anti-seize; tighten to the proper
torque
—
Guide
Bushing
Remove the bushing
Reinsert the bushing
Check for wear
Seal
Remove the seal
Replace with a new seal
—
Stem
Packing
Remove the stem
packing
Replace with new stem packing
—
Spindle
Remove the spindle
Reinsert the spindle – 2 flat
surfaces should fit into the slot in
the ball
Check the 2 flat
surfaces for
deformation,
wear, scratches,
corrosion, etc.
Valve Shaft Remove the valve shaft Reinsert the valve shaft
Check for wear,
deformation, etc.
Gland Seat Remove the gland seat Replace with a new gland seat with
the proper orientation
—
Washer
Remove the washer
Reinsert the washer
Check for
damage,
deformation, etc.
Belleville
Washer
Remove the Belleville
washer
Reinsert the Belleville washer with
the proper orientation
Check for
damage,
deformation, etc.
Holder
Gasket
Remove the gasket and
clean sealing surfaces
Replace with a new gasket if
damaged; be careful of the
orientation when inserting
—
Part
Valve
Size
Torque
Distance
Across
Flats
mm
N∙m
mm
Holder
Screw
15 – 50
1.2
2
Holder
15 – 25
50
17
32 – 50
80
27
(1 N∙m
≈
10 kg∙cm)
NOTE:
1. Reassemble the gland section only after
first reassembling the valve section.
2. To facilitate reinsertion of the spindle and
valve shaft into the ball, for the screwed
model first finger-tighten the inlet union,
for the flanged model first finger-tighten
the flange. This centers ball, thus making
it easier to reassemble. When
reassembly is completed, tighten the
valve holder.
Holder
Guide Bushing
Seal
Stem Packing
Spindle
Valve Shaft
Gland Seat
Washer
Belleville Washer
Holder Gasket
Holder Screw