Gasmizer Manual - Submarine Manufacturing and Products Ltd

March 2009
Re-assembly:
1. Assemble the first pair of wiper rings with the plain faces to the crosshead end,
with the slotted face upper most.
2. The second pair of wiper rings are assembled reversed (slotted face to crosshead
end, plain face uppermost).
NOTE
Take care not to damage the white metal scraping edges.
3. Use the packing loading tool no. GE077 when passing the piston rod through the
packings.
4. Torque settings for the wiper packing caphead screws is 4 ft-lb (3Nm).
9.9.7 Crosshead and Piston Rod Assembly
Disassembly:
1. Loosen and remove the four flange nuts.
2. Remove the crosshead guide, supporting the connecting rod and crosshead/
piston rod assembly to avoid damage as the guide is lifted clean.
3. Cover the crankcase with cloth to prevent ingress of foreign matter.
4. Mark the crosshead before removal so that it will be replaced in its original
position, remove the gudgeon pin circlips and centrally apply pressure to push out the
gudgeon pin (whilst supporting the crosshead if a drift is found to be necessary).
NOTE
The crosshead and piston rod has been machined as an assembly, no attempt should be made
to separate them.
Maintenance:
Examine all parts for signs of wear and renew if necessary.
Wear limits:
Crosshead Diameter
3.995” (101.6mm) MIN
3.9975” (101.53mm) MAX
Crosshead Guide Bore Diameter 4.00” (101.6mm) MIN
4.003” (101.67mm) MAX
NOTE
Maximum total clearance between the piston and guide bore is 0.006” (0.152mm)
Piston Rod Diameter
0.999” (25.375mm) MIN
1.00” (25.4mm) MAX
NOTE
Check all clearances cold.
Chap 9 Page 115 of 168 OM002 Rev 5