4
3 DESCRIPTION OF SAFETY VALVES
Crosby Style HC/HCA safety valves are shown
in Figures 1 and 2. These drawings illustrate
the safety valves assembled in cross-section,
and cover the essential elements of the valves.
Approved drawings supplied with the valves
should be used when installation and/or
specific information is required.
Inside the body (1A) is housed the upper portion
of the nozzle (1B), nozzle ring (3), and the
guide ring (10). The disc insert (5) is held in
place in the disc holder (6) by the spindle and
disc holder retainer nut (7). The nozzle ring
and adjusting rings are held in place by the
nozzle ring set screw (4) and the guide ring set
screw (11), which are threaded into the body.
4 STORAGE
Often, safety valves are on the job site
months before they are installed. Unless
they are stored properly and protected, their
performance may be affected seriously.
Rough handling may damage flanges or cause
misalignment of the parts. It is best to leave the
safety valves in their shipment cases and store
them in a dry place under cover until they are
to be installed.
FIGURE 3 - VALVE BODY AS SHIPPED
FIGURE 4 - VALVE SUPERSTRUCTURE AS
SHIPPED
TOP VIEW - BODY
HYDRO COMPONENTS (see note 1, page 5)
CROSBY
®
STYLES HC AND HCA ISOFLEX™ SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
Ordering spare parts
When ordering spare parts, the valve size,
style and shop number and/or serial number
should be given together with set pressure,
part name and reference number. The valve
assembly number is shown on the valve
nameplate as 'Shop number'. Spare parts may
be ordered from any Emerson sales office
or representative.
Crosby Style HC/HCA ISOFLEX nameplate
(With sample information for illustrative
purposes only)
The guide (9) is retained between the body (1A)
and the bonnet (13) by the bonnet studs (14)
and the bonnet studs nuts (15). In the case of
Style HCA valves, a cooling spool (43) is placed
between the body and bonnet to protect the
spring from exposure to extreme temperatures.
The bonnet (13) contains the spring (16),
spring washers (17 and 18) and the spindle
assembly (12). The spindle point is held in
compression between the back face of the disc
insert (5) and the bottom spring washer. The
spring is compressed between the stationary
point of contact with the spindle and the
adjusting bolt (21A) atop the valve bonnet.
The adjusting bolt (21A) is locked in place by the
adjusting bolt nut (22) on top of the bonnet and
within the cap assembly. A means of manual
lifting is provided by the lever (27), lever pin (28),
forked lever (30), forked lever pin (31) and the
spindle nut (23).
