10
CROSBY
STYLE HSL SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
Refurbishing discs and disc inserts
When the damage to the disc or disc insert
seat is too severe to be removed by lapping,
the disc or disc insert should be replaced.
Re-machining of the disc or disc insert seat
is not recommended. The disc or disc insert
seating surface may be lapped provided that the
minimum overall disc height shown in Figure 8
is maintained.
Valve assembly
All components should be clean. Before
assembling the following parts, lubricate with
pure nickel 'Never-Seez' or equivalent.
• Nozzle and body threads
• Nozzle and body sealing surfaces
• All stud and nut threads
• Spindle bearing surfaces and threads
• Set screw threads
• Spring washer bevels
• Adjusting bolt and bonnet threads
For parts identification, refer to Figures 1 and 2.
A. Before installing the nozzle, lubricate the
flange surface in contact with the valve body
and on the nozzle threads. Then screw the
nozzle into the valve body and tighten until
the nozzle flange is seated fully against the
valve body.
B. Screw the nozzle ring onto the nozzle.
Note:
the top of the nozzle ring should be
approximately one ring revolution above the
nozzle seating surface.
C. Thread the spindle assembly into the disc
holder or disc. Turn the spindle until it drops
off the internal threads and contact is made
between the spindle ball and the disc or disc
holder bushing.
Note:
If spindle does not thread into disc, check
the design version number in the model number
for compatibility. Do not force the spindle to thread
into the disc. Reference Valve Design Version and
Interchangeability Section for more detail on the
design version numbers, and contact Emerson to
get the correct disc and spindle.
H. Place the spring and washers assembly
onto the spindle. Lower the bonnet over the
spindle and spring, onto the bonnet studs
in the body. In closed bonnet valves, the
bonnet vent should be aligned with the valve
outlet. Position the bonnet counter bore on
the OD of the guide and lower the bonnet
onto the guide.
I. Screw the bonnet stud nuts onto the
bonnet studs and tighten down evenly to
prevent unnecessary strain and possible
misalignment.
J. Lift the disc insert slightly by lifting the
spindle rod. Lower the nozzle ring below the
seats. Release the spindle slowly to permit
the disc insert to contact the nozzle seat
gently. Check that the nozzle ring moves
freely.
K. Screw the adjusting bolt and nut into the
top of the bonnet the same number of
turns originally required to remove the
spring load. The original set pressure can
be approximated by screwing the adjusting
bolt down to the height above the bonnet
measured during disassembly.
L. Move the nozzle ring up until it touches
the disc holder. From this position lower it
to the original recorded position. Move the
guide ring until the bottom of the guide ring
is at the same level as the bottom face of
the disc or disc holder assembly. If the guide
ring position originally recorded is a positive
number, raise the guide ring by the number
of notches indicated. If a negative number,
lower the ring that number of notches. Rings
are moved up by turning them to the right
and lowered by turning them to the left.
M. Screw the set screws into the body,
engaging both the nozzle ring and the guide
ring. Both rings should move back and forth
slightly after the set screw is tightened.
N. The valve is now ready for testing per
test procedure T-16758. After testing, the
following steps should be taken:
1. Be sure that adjusting bolt nut is locked.
2. Install the cap assembly (see overleaf).
3. Seal wire the cap and set screws to
prevent tampering.
For test/adjustment procedures refer to page 6.
'B' min. after lapping
F thru J orifice disc
K thru Q orifice disc insert
'B' min.
after lapping
FIGURE 8
See Table 3
See Table 3
D. If the valve has a 2 piece disc design, place
the disc insert into the disc holder. Turn the
insert until the alignment is achieved between
the hole in the button end of the insert and
the hole in the bottom end of the holder.
Insert disc insert cotter pin to hold in place.
E. Thread the guide ring onto the guide.
F. Install the guide and guide ring assembly
into the top of the body. The guide of valve
should be seated directly on the top surface
of the valve body. Maintain proper alignment
between the guide and the body to ensure
that the guide is seated correctly in the body.
G. Lower the spindle and disc or disc holder
assembly into the guide and onto the nozzle.
