wT 1255/12
Page 16
11.3
Bonnet Disassembly and Assembly
!
CAUTION
All individual parts, especially the sealing surfaces, must be thoroughly
inspected prior to assembly. Damaged parts must be replaced with new
parts. Visible dirt on the machined parts must be removed.
!
CAUTION
Special care must be taken to avoid the KX-GT rings being inserted into
the bore if they become jammed with the mounting tool.
»
Remove valve ring (Pos. 16) from the bonnet
»
Loosen handwheel securing nut (Pos. 30)
»
Remove serrated lock washer (Pos. 35) and handwheel (Pos. 3)
»
Remove hex nut (Pos. 29) and belleville washers (Pos. 34) and lift the gland retainer
(Pos. 11)
»
Screw out spindle (Pos. 9) of the threaded bush (Pos. 20)
»
Pull out the piston shaft with the spindle downwards out of the stuffing box ring set
(Pos. 17)
»
Tap out the stuffing box ring downwards via the securing ring (Pos. 22), without
damaging the surface of the body’s bore, clean the bore
»
In the event that the threaded bush displays damage, the bonnet must be secured in
a vise and the tensions pins (Pos. 31) knocked out from the outside inwards
»
Unscrew the threaded bush
»
Screw the new threaded bush in, drill holes and pin
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Place washer (Pos. 22) in the stuffing box drilling, position stuffing box ring set (Pos.
17) and press in by using the gland retainer (Pos. 11) and remove gland retainer
afterwards
»
Place gland retainer, mount belleville washers and slightly bolt hex nuts (Pos. 7) but
do not tighten them
»
Secure the assembly of the piston (piston, piston shaft, spindle) at the piston shaft
(Pos. 7) in a vise under utilization of soft brackets
»
Disassemble the securing rings (Pos.26) and piston nose cone (Pos. 13) from the
piston
»
Screw off hex nuts (Pos. 28) (left-handed thread) and remove disc (Pos. 23), piston
and back seat (Pos. 6)
»
Loosen split nut (left-handed thread) (Pos. 21) and remove disc (Pos. 12) from the
piston shaft
»
Replace damaged parts with new parts
»
Installation of the spindle (Pos. 8) and disc (Pos. 17) into the piston after thorough
lubrication of the spindle head
»
Insert the back seat (Pos. 6) in the piston and fit both on the piston shaft, after
thorough lubrication of the piston plug
»
Bolt piston onto piston shaft with disc (Pos. 23) and hex nut (Pos. 28)
»
Place position nose cone (Pos. 13) in the piston and mount with the securing ring
(Pos. 26)
»
Insert the assembly of the piston (piston, piston shaft, spindle) from below in the
stuffing box set and screw spindle into threaded bush after thorough lubrication
»
Mount hex nuts (Pos.29) of the gland retainer by applying tensioning torques as
provided in the table
»
Mount handwheel and serrated lock washer
»
Mount handwheel nut by applying tensioning torque as provided in the table