18
CROSBY
®
STYLES HC AND HCA ISOFLEX™ SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
Setting of rings
The nozzle ring (3) setting is stamped on the
machined surface of the bonnet (13) where the
cap (25) sits. For example, NR-15 means set
the nozzle ring fifteen notches below contact
with the disc holder (6). To set the nozzle ring,
turn it to the right (counterclockwise) until it
touches the disc holder. From this position,
lower it by the number of notches indicated to
the stamped position.
The guide ring (10) setting is obtained in
the same manner as the nozzle ring above.
For example, GR +30 means thirty notches
above level position. Level is when the bottom
of the guide ring is even (level) with the bottom
of the disc holder. This position is illustrated in
Figure 9. With the safety valve already on the
system, level can be obtained by inserting a
metal rod with a hook on the end through the
lower set screw hole and feeling the position of
the ring in relation to the disc holder.
To set the guide ring, move it to the level
position. If the stamped guide ring position is
a positive number, turn the ring to the right
(counterclockwise) to raise the guide ring by
the number of notches indicated. If the stamped
guide ring position is a negative number, turn
the ring to the left (clockwise) to lower the ring
that number of notches.
Lubricate the set screws (4 and 11) threads.
Screw the set screws into the body (1A)
engaging both the nozzle ring (3) and guide
ring (10). Both rings should be able to move
back and forth slightly after the set screws
are tightened.
Assembly of cap (see Figure 1)
The assembly of the cap is referred to several
times in this instruction. The cap assembly
consists of the spindle nut (23); cap (25); forked
lever assembly: forked lever (30), forked lever
pin (31) and forked lever pin cotter (32); and the
lever assembly: lever (27), lever pin (28) and
lever pin cotter (29).
11 SPARE PARTS
Emerson recommends spare parts as shown
on the parts list with corresponding notes.
When ordering spare parts, the valve assembly
number should be given together with part
number and valve size and style. The valve
assembly number is shown on the valve
nameplate as shop number (see Section 2 -
paragraph 'Crosby Style HC/HCA ISOFLEX
nameplate'). Any Emerson sales office or
representative can expedite your spare parts
requirements.
The lever assembly can be removed from
the safety valve independently of the cap.
The cap cannot be removed from the safety
valve without first removing the forked lever
assembly.
The cap set screws (26) are seal wired to
prevent tampering with the adjusting bolt (21).
To assemble the cap assembly, proceed as
follows:
If the spindle nut (23) was removed, lubricate
the spindle rod (12B) threads and install the
spindle nut (23) and the spindle nut cotter (24).
Install the lever (27), lever pin (28) and lever pin
cotter (29). Place the cap in position but do not
tighten the cap set screws yet.
Install the forked lever (30), forked lever pin (31)
and forked lever pin cotter (32). Be sure that
the forked lever is free to move from
1
/
16
” to ⅛”
before coming into contact with the spindle
nut (23).
If travel is excessive, remove the forked lever
and cap and turn the spindle nut clockwise or
counterclockwise to increase or decrease the
forked lever travel.
Be sure the spindle nut cotter (24) is installed
after the final adjustment.
