Gasmizer Manual - Submarine Manufacturing and Products Ltd

March 09
removed by re-louping coolant holes and chambers should be cleaned of sediment and
scale.
3. When fitting new P T F E packing elements the piston rod must be roughened to
enable the new elements to ‘bed in’.
Use 200 grit emery cloth to impart a 45 o crosshatch type finish to the swept area of the
piston rod.
4. Wash off all traces of abrasive material with a suitable solvent.
NOTE
Failure to roughen the piston rod will cause premature wear of the new PTFE elements due to
excessive piston rod temperatures.
Re-assembly
1. The packing must be re-fitted into the containers in the correct order.
2. Re-fit the containers in the correct order (numbers are stamped on the outside
diameters), renew ‘O’ rings where necessary. Care must be taken that the ‘O’ rings are
seated correctly in their grooves.
3. Correct alignment of the coolant, lubrication and vent lines is ensured by the tie
studs fitted through the packing and screwed into container nearest the piston.
4. Coupling connections from the case are stamped with identification letters
(coolant Inlet – “C1”, Coolant Outlet – “C2”, Vent – “V”).
5. Use packing loading tool no. GE077 when passing the piston rod through the
packings.
6. Torque settings for the pressure packing nuts is 24 ft-lb (17.7Nm).
9.9.6 Wiper Packing Unit
Description:
This packing unit consists of two pairs of Babbit metal segmented wiper rings sprung
onto the rod with garter springs. These wiper rings scrape the oil from the rod back into
the crankcase via drain channels.
Disassembly:
1. Loosen and remove the six socket screws from the top cover, remove top cover
exposing the top pair of wiper rings.
2. Remove wiper rings ensuring that each set of segments and rings are kept
together as a set because they must be re-assembled exactly as the came out.
3. Remove container and second set of rings.
Maintenance:
1. When the packing rings have worn until the ends butt they must be replaced.
2. Container faces must be fluid tight, scores and indentations must be removed by
lapping.
OM002 Rev 5 Page 114 of 168 Chap 9