Repair Procedure - Emerson CROSBY STYLE HC ISOFLEX Installation, Maintenance And Adjustment Instructions

CROSBY
STYLES HC AND HCA ISOFLEX™ SAFETY VALVES
®
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
Initial safety valve assembly
After hydrostatic testing using hydrostatic test
plugs, the safety valves should be assembled.
NOTE
It is recommended that, on completion of all
hydrostatic tests using hydrostatic test plugs on new
installations, a Emerson service technician be present
for assembly of the safety valves (see Section 12 -
'Field service requirements').
Check the valve identification numbers and
match the proper valve superstructure to each
valve body.
The nozzle ring (3) and the set screws (4 and 11)
are packaged together and shipped with the
superstructure as shown in Figure 4.
CAUTION
Each valve superstructure, nozzle ring and set
screw is identified and matched to a specific valve
body by a tag number and should be assembled
accordingly. Although all parts have been cleaned
thoroughly, inspected, lubricated and protected
for shipment, the parts should be inspected
before installation for evidence of foreign matter
or damage. Special attention should be given
to the seating surfaces of the disc and nozzle.
These seats should be free from surface damage.
If cleaning or repair is necessary refer to
Section 9 - paragraph 'Repair procedure'.
Initial assembly
Remove the body protective cover (see
Figure 3).
Take the nozzle ring (3), nozzle ring set
screw (4) and guide ring set screw (11) from
their package (see Figure 4). Match the set
screws to the body (1A) and bonnet (13) valve
identification markings.
Screw the nozzle ring (3) onto the nozzle (1B).
NOTE
The top of the nozzle ring (3) should be about one ring
revolution above the nozzle (1B) seating surface.
Remove the guide (9) and guide ring (10)
from the superstructure. The guide ring
should be screwed onto the guide. Install
the guide and guide ring assembly into the
top of the body (1A). Make sure the guide is
seated correctly in the body. Make sure that
the nozzle (1B) and disc insert (5) seats are
clean and undamaged. If cleaning or repair
is necessary refer to Section 9 - paragraph

'Repair procedure'.

Remove the lever (27), forked lever (30) and
cap (25) from the valve superstructure. Do not
remove the spindle nut (23).
Using a suitable lifting device, lift the valve
superstructure with the spindle assembly (12)
vertical. Inspect and clean the guide-to-bonnet
fit and the body-to-guide fit. Position the
superstructure so the valve identification
number stamped on the bonnet (13) is
opposite the valve outlet.
Lowering the valve superstructure slowly,
carefully lower the disc holder (6) into the
guide (9).
CAUTION
Do not permit any rocking motion of the
spindle (12) or any other part while lowering the
superstructure into the body (1A). Any rocking
motion could damage the valve seats.
After the superstructure in in place, inspect
to be sure the bonnet (13) is fully seated on
the guide (9).
The nozzle ring (3) should now be lowered.
Lift the disc insert (5) slightly off the
seat by lifting the spindle assembly (12).
Place a screwdriver in the lower set screw hole.
Turn the nozzle ring to the left (clockwise) with
the screwdriver until the top edge of the nozzle
ring is below the nozzle (1B) seating surface.
The location can be checked by looking in
through the upper set screw hole while shining
a light through the lower set screw hole.
Lower the spindle assembly slowly until
it bottoms. Check that the nozzle ring
moves freely.
Rotate the spindle clockwise several
revolutions to make sure that it is seated fully
on the disc insert and that the threads of the
spindle are not engaged.
The seating surfaces are now in full contact.
Install the bonnet stud nuts (15) on the bonnet
studs (14) and tighten uniformly in accordance
with Figure 6.
It is now necessary to remove the spacer blocks
under the bottom spring washer (17), thereby
transferring the spring load to the valve seats.
This should be done using the hydraulic jacking
device (see Figure 14). Refer to instruction
I-1167 for detailed instructions in the use of this
device.
After the spacer blocks have been removed, set
the nozzle ring (3) and guide ring (10) according
to Section 10 - paragraph 'Setting of rings'.
Lock the nozzle ring set screw (4) and the
guide ring set screw (11) in place, making sure
that the proper set screws are installed and
engaged fully in a notch. Lock wire them in
place and seal.
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