Gasmizer Manual - Submarine Manufacturing and Products Ltd

March 09
NOTE
Never use reversed worn valve plates.
6. Springs: When ANY spring shows signs of deterioration ALL springs in that valve
assembly must be replaced.
7. Seats: For the booster to work at its maximum efficiency it is important that the
seat face is flat and free of any traces of wear or damage. If any is found it will be
necessary to return the valve assembly to GSOL or W & J for remachining of the
seating areas. Locating pins should be replaced if worn, taking care to ensure that the
new pin protrudes the same length as the original pin.
Re-assembly:
Re-assemble the valve in the correct sequence (refer to drawing nos. 81927, 81928,
81929). When retightening the centre nut proceed as in (2) above.
The tightening torque is 14.5/17.8 ft.lbs (19.7/242.1 Nm).
9.9.4 Pistons and Cylinders
Description:
The 1 st stage piston is 4 1/4" diameter and the 2 nd stage piston is 2 5/8” diameter. Both
are made from aluminium alloy and are fitted with seven piston rings and one guide
ring made from filled T.F.E.
The cylinders are of cast iron fitted with stainless steel liners. Inlet pressure acts on the
underside of the piston through tappings in a distance plate mounted below the
cylinder. A water jacket encloses the cylinder.
Disassembly:
1. Remove cylinder head assembly (see 9.9.1).
2. Remove water manifold and jacket.
3. Loosen and remove the six flange nuts retaining the cylinder.
4. Lift off the cylinder.
5. Remove the bolt on the crown of the piston and remove the piston.
6. Alternatively the piston can be removed with the cylinder in situ by fitting two 1/4”
UNC bolts for extraction, removing the piston crown bolt and lifting out the piston
assembly.
Maintenance:
Wear limits on cylinder components are:
Cylinder Bore Diameter 4.25” (107.95mm) MIN
4.251” (107.979mm) MAX
Piston Diameter
4.1548” (105.53mm) MIN
4.157”(105.58mm) MAX
Guide Ring
Radial Thickness
0.22” (5.59mm) MIN
0.25” (6.35mm) MAX
OM002 Rev 5 Page 112 of 168 Chap 9