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Operation & Maintenance Instruction
•
To prevent receiving electrical shock when
performing electrical test, hands must be clear of
electrical components, contacts and housing and
the required "in-lab" grounding procedures must
be strictly adhered to. A wooden work bench should
be used. Failure to heed this WARNING could result
in severe injury or death.
•
An adequate support or lifting device must be
available to support the Device and/or Valve
Portion(s) during removal, installation and
maintenance procedures.
6.0 CLEANING SOLVENT, LUBRICANT, SEALANT AND
SPECIAL TOOLS
6.1.1 The solvent used to clean the reusable parts of the VX
Vent Valve Portion MUST BE an aliphatic hydrocarbon solvent,
such as mineral spirits or naptha, that will dissolve oil or
grease and that will permit the parts to be cleaned without
abrasion.
IMPORTANT: Cleaning solvents are to be used in a well
ventilated area.
6.2 LUBRICANTS
6.2.1 Number 2 Silicone Grease, Wabtec Corporation
Specification M-7680-2, (Industry Designation MIL-G-4343),
such as Dow Corning Corporation Dow Corning 55, is required
for the lubrication of specified o-rings, o-ring grooves and the
o-ring bearing surfaces of the bushing(s) which will be in
contact with the o-rings.
6.2.2 A compound consisting of one part of graphite, Wabtec
Corporation Specification M-7695-2, (AAR Specification M-
913), such as Super Flake Graphite Company - Superfine
Number 597 Joseph Dixon Crucible Company - Microfyne
Graphite or National Carbon Company Number 38 or 39
Graphite, and two parts of SAE-20 oil by weight is required
for the lubrication of the threads of the cleaned or NEW piston
choke plug prior to the installation of this choke plug in the
piston.
6.3.1 Locking Sealant, Wabtec Corporation Specification M-
7499-05, such as Loctite Corporation TL-242, is required for
application to the threads of the piston stem prior to the
installation of the piston jam nut.
7.0 MAINTENANCE PROCEDURES
NOTE: When performing the procedures which follow, DO
NOT use hard or sharp tools to remove o-rings, gaskets,
seals or the diaphragms. Exercise care so that no damage
is done to reusable parts.
WARNING; When performing the procedures which
follow, springs within the assembly may be placed
under compression. Exercise care so that no parts are
inadvertently expelled. Inadvertently expelled parts
may cause bodily injury and/or damage to parts.
7.1 DISASSEMBLY
NOTE: The VX Vent Valve Portion weighs approximately 7
pounds.
7.1.1 If the mounting gasket is still in its groove in the
mounting face of the body (2), it is to be removed and
SCRAPPED. The gasket IS NOT a part of the VX Vent Valve
Portion and is not illustrated.
7.1.2 Remove and SCRAP the wire mesh strainer (3) from
its port in the body (2).
7.1.3 Remove the four
which secure the housing (19), filling piece (9), and body (2)
together.
7.1.4 Carefully remove the body (2) from the filling piece (9),
then remove the filling piece with diaphragm and diaphragm
clamping plate subassembly (5, 6, 7, 9) from the housing
(19) as a unit.
7.1.4.1 Remove the spring (8).
7.1.5 Remove the three #8 x
which secure the diaphragm clamping plate (6), diaphragm
(7) and filling piece (9) together.
7.1.6 Remove the diaphragm clamping plate (6) and
diaphragm (7) from the filling piece (9). SCRAP the
diaphragm (7).
7.1.7 Remove and SCRAP the 5
groove in the filling piece (9).
7.1.13 Remove the piston-diaphragm sub-assembly (13,
14, 15) as a unit from the piston stem (17) and diaphragm
follower (16).
Page 5 of 10
4211-7, S.7
3
/
" x 1
1
/
" hex. head cap screws (1)
8
2
1
/
" button head screws (5)
2
1
/
" O.D. o-ring (4) from its
4
September, 2017
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