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Crosby style JCe safety ValVe
InstallatIon, MaIntenance and adjustMent InstructIons
5.3 general examination
ensure that the bore of the guide plate (9) is
in good condition, and that the spindle (10)
where it passes through the guide (9) and the
adjusting screw bush (77) is free from any
surface defects. ensure that the adjusting
screw bush (77) is not worn. examine the ball
location points in the disc (5) and the spindle
(10) and ensure that they are of a clean smooth
finish. examine the ball (31) for surface
imperfections and replace if damaged. If the
spring is corroded it should be replaced.
5.4 resilient seal
If the resilient O-ring (53) is damaged it should
be replaced. the seal is removed from the disc
(5) by following the procedure outlined in 4.2.3.
5.5 bellows
If the bellows unit is damaged, distorted or
corroded in any way it should be replaced.
6 rEassEMbly
6.1 Conventional metal seated valves
6.1.1 apply grease to both ball and adjusting
screw. Place the ball (31) in position on
the disc (5) and position the disc assembly
onto the seat (4). Place new gasket (27)
onto the guide recess in the body.
6.1.2 fit the spindle (10) on to the ball (31) and
slide the guide plate (9) into position in
the body recess. ensure that the spindle
(10) is free to move. fit the split collar (69)
onto the spindle (10) and slide the lower
spring plate (11) into position. ensure that
the spring plate (11) is fully located on the
split collar. Place a new gasket (27) onto
the guide plate (9).
If the valve is an 80 mm or 100 mm high
pressure model the cover spacer (68)
should be positioned onto the guide plate
(9) and the 4 nuts (21) tightened. a new
gasket should be positioned on top of the
spacing piece.
Place the spring (22) onto the lower
spring plate (11) and fit the upper spring
plate (11) onto the spring (22). lower the
bonnet (2) over the spindle (10) and onto
the guide plate (9). tighten down fully the
4 nuts (19). slide the adjusting screw (12)
over the spindle (10) and screw it into the
bonnet (2). set the adjusting screw (12) to
its original position and secure with the
locknut (13).
6.2 bellows metal seated valves
6.2.1 Place the ball (31) in position on the disc
(5) and the lift stop (81).
6.2.2 Place a new gasket (27) onto the body
recess and position the spacing piece
(47) onto the body (1). Position the disc/
bellows assembly onto the seat (4) and
ensure that the bellows flange locates
squarely into the spacing piece recess.
follow the procedure outlined in 6.1.2
to further assembly the valve. It is
very important that an effective seal is
achieved between the bellows flange and
the guide plate.
6.3 resilient valves
Place the 0-ring (53) into position on the disc (5)
along with the retaining plate (65). secure the
assembly with the circlip (66) ensuring that the
retaining plate (65) is centrally located on the
0-ring (65).
follow the relevant procedure outlined in 6.1.1
or 6.2.1 to further re-assemble the valve
6.4 Pressure setting
the set pressure on gas/vapor is defined where
audible discharge occurs. On liquid valves
this is defined where the first steady stream
of liquid occurs. In both cases, the pressure
gauge measuring inlet pressure will stop rising
when set pressure is reached.
ensure that the internal surfaces of the valve
inlet and test rig are clean and mount the
valve securely on the test rig. set the valve to
the required pressure using air or nitrogen
for valves intended for gas or vapor service.
Inhibited water should be used for valves
intended for liquid duty. adjust the adjusting
screw (12) until the required set pressure is
achieved and pull up the locknut (13). finally
check that the set pressure has not altered.
Refit the cap (3) using a new gasket (28) if
applicable. to reassemble the packed and
marine caps reverse the procedure described
in 4.4 or 4.5.
7 suPPlEMEntary notEs
7.1
Danger can emanate from the incorrect
installation, maintenance and adjustment
of this product. for this reason only
qualified persons are permitted to work
on the product within the guidelines
supplied by the manufacturer.
7.2
failure to adhere to these instructions
will invalidate any Ce marking.
3
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