6
Crosby
SerieS HSJ Safety valveS
InstallatIon, operatIon and maIntenance InstructIons
guide ring adjustment
the guide ring (9) is the principal blowdown
control ring in the valve. to change the guide
ring position, remove the guide ring set screw
(10) and insert a screwdriver to engage one of
the notches. turning the guide ring to the right
raises it and decreases the blowdown. turning
the guide ring to the left lowers the ring,
thereby increasing the blowdown.
the guide ring (9) should never be moved more
than ten notches either way without retesting
the valve. after each adjustment always
replace, tighten and seal wire the set screw
being careful that its point fits in the notch in
the ring without making contact with the ring or
bearing on top of a tooth.
nozzle ring adjustment
the nozzle ring adjustment is determined
carefully by factory test and resetting in
service is seldom necessary. Should it be
necessary, the nozzle ring (3) is adjusted by
removing the nozzle ring set screw (4) and
inserting a screwdriver to engage the ring
notches. turning the ring to the right raises
it and results in a strong 'pop' action that will
increase blowdown. Moving the ring to the left
lowers the ring, decreasing the blowdown and
may result in warn or simmer if lowered too far.
the range of adjustment of this ring is limited
and it should not be moved more than one
notch at a time from its set position. the valve
performance should be checked after each
adjustment. after each adjustment always
replace, tighten and seal wire the set screw (4),
being careful that its point fits in the notch
without making contact with the ring or bearing
on top of a tooth. it is very important not to let
the valve pop before the nozzle ring set screw
has been reinstalled and tightened.
restamping
if different ring locations are obtained after
testing, restamp the valve bonnet with the new
(tested) ring settings.
8 valve maintenanCe
the functioning and service life of a safety
valve depends primarily on methods used in
its maintenance. for this reason, the following
maintenance procedures are recommended:
disassembly
When possible, remove the valve from the
system before dismantling. there should be
no system pressure when a valve is either
dismantled in place or removed for shop repair.
for parts identification, see figure 1 on page 2:
a. remove the cap (19) and lifting lever device
(if any) following the instructions on page 8.
c. Before releasing the spring load, measure
and make note of the height of the adjusting
bolt (17) over the top of the bonnet (14). this
information will help when reassembling the
valve to its approximate original setting.
d. loosen the adjusting bolt nut (18). Count the
number of turns required to remove the spring
load by rotating the adjusting bolt (17) in a
counterclockwise direction.
e. loosen and remove bonnet stud nuts (16).
f. Carefully lift the bonnet (14) straight up to
clear the spindle (11) and valve spring (12).
exercise care when lifting the bonnet as the
spring and spindle will then be free to fall
aside.
g. lift the spring (12) and spring washers (13) off
the spindle. the spring and spring washers
are fitted together and must be kept together
as a subassembly. Spring washers are not
interchangeable between ends of the spring.
h. the disc holder assembly (5) or disc (6a) and
spindle (11) can now be removed from the
valve body (1) by lifting the spindle.
i. remove the guide (8) and guide ring (9) from
the body (1) as an assembly and unscrew the
guide ring from the guide.
j. if the valve has a 2-piece disc design
(insert and holder), remove the disc insert
cotter pin (7) and the disc insert (6) from the
disc holder assembly (5).
k. remove the spindle (11) from the disc holder
assembly (5) or disc (6a) by pulling up on
the spindle rod to engage the spindle point
threads in the disc/holder. turn the spindle
counterclockwise while holding the disc/
holder still and remove the spindle rod.
l. unscrew the nozzle ring (3) from the nozzle (2).
m. unscrew the nozzle (2) from the body (1).
Caution
Never loosen bonnet stud nuts before completely
releasing spring tension with the adjusting bolt.
Caution
Nozzle and guide ring set screws are custom
fitted to each valve and are not to be interchanged.
b. remove the nozzle ring set screw (4). Check
the nozzle ring setting by turning the nozzle
ring (3) to the right and counting the number
of notches turned until it makes contact with
the disc holder assembly (5). record the
number of notches. this location is given as
minus (-) notches from this contact position.
remove the guide ring set screw (10). Check
the guide ring setting by returning the guide
ring (9) to its level position. the guide ring
is in level position when the bottom face
of the guide ring is level with the bottom
face of the disc holder assembly (5). the
guide ring should be turned to the right or
left, whichever is necessary to return it to
its level position. the guide ring position is
recorded as minus (-) (down) or plus (+) (up)
notches from this level position.