Emerson CROSBY HE ISOFLEX Series Guide

CROSBY SERIES HE ISOFLEX®SELF-ACTUATED SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
SAFETY
The safety of lives and property often depends
on the proper operation of the safety valves.
Consequently, the valves should be kept
clean and should be tested periodically and
reconditioned to make sure they function
properly.
Emerson.com/FinalControl © 2017 Emerson. All Rights Reserved. VCIOM-01067-EN 18/08
Engineering Doc. #IS-V 3155B
WARNING
Suitability of the material and product for
the use
contemplated by the buyer is the sole responsibility
of the buyer. Also storage, installation and proper
use and application are the sole responsibility of the
purchaser. Emerson disclaims any and all liability
arising out of the same.
Any installation, maintenance, adjustment, repair
and testing performed on safety relief valves should
be done in accordance with the requirements of
all applicable codes and standards under which
those performing such work should maintain
proper authorization through appropriate governing
a
uthorities. No repair, assembly and test work
done by other than Emerson shall be covered
by the warranty extended by Emerson to its
customers. You assume full responsibility for your
work. Inmaintaining and repairing Crosby products
you should use only parts manufactured by
Emerson. Callyour nearest Emerson sales office
or our factory for a Crosby valve service engineer
should you wish assistance with your field needs.
SAFETY PRECAUTIONS
Proper installation, maintenance and operation
is essential to the safe and reliable operation of
all pressure relief products.
Precautionary statements in the form of
warnings, cautions and notes are used in this
manual to emphasize important and critical
instructions where applicable.
Examples:
WARNING
An operating procedure or practice which, if not
observed strictly, may result in injury to personnel
or loss of life.
CAUTION
An operating procedure or practice which, if not
observed strictly, may result in damage to or
destruction of equipment.
NOTE
An operating procedure or condition which is
highlighted, underlined or printed in bold type for
emphasis.
These precautionary statements are not
exhaustive. Emerson cannot possibly
know, evaluate and advise customers of all
conceivable ways in which tasks might be
performed, or of the possible hazardous
consequences of each way. Consequently,
Emerson has not included such comprehensive
evaluation and disclaims liability for work
performed by other than Emerson personnel.
All personnel working with Crosby products
should be trained adequately and be thoroughly
familiar with the contents of this manual.
Emerson cannot evaluate all conditions that
might injure personnel or damage equipment.
However, Emerson does offer the following
general safety precautions:
- Hearing and eye protection should be used
when working on a valve which is under
pressure.
- Never strike a valve which is under pressure.
Premature actuation can result.
- Never stand in front of the discharge outlet
of a pressure relief valve which is under
pressure.
Always approach and use any pressure relief
valve with great care.
TABLE OF CONTENTS
1. Introduction ....................................................3
2. Factory preparation of welded inlet
valves for shipment........................................3
3. Preparation of valve for service.....................3
4. Initial valve assembly .....................................5
5. Description of operation ................................7
6. Set pressure testing and adjustment ...........8
7. Valve maintenance .........................................9
8. Repair procedure .........................................11
9. Valve assembly.............................................14
10. Spare parts ...................................................15
11. Field service recommendations..................15
12. Maintenance equipment ..............................16

2
34
28
15
33
30
31
13
18
19
9
10
11
4
3
5
26
27
24
22
20
12
17
7
6
1B
1A
21
25
14
CROSBY SERIES HE ISOFLEX®SELF-ACTUATED SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
PARTS LIST
Part ref. no. Part name Spare parts designation (See notes 1, 2, 3)
1A Body
1B Nozzle
3Nozzle ring 2
4Nozzle ring set screw 2
5Disc insert 1
6Disc holder 2
7Disc holder retaining nut
9Eductor 2
10 Guide ring 2
11 Guide ring set screw 2
12 Spindle assembly 3
13 Piston
14 Piston retaining ring 2
15 Spindle nut
17 Bonnet
18 Bonnet studs
19 Bonnet stud nuts
20 Spring 3
21 Bottom spring washer 3
22 Top spring washer 3
24 Bearing adapter
25 Thrust bearing
26 Adjusting bolt
27 Adjusting bolt nut
28 Cap
30 Lever
31 Lever pin
33 Forked lever
34 Forked lever pin
FIGURE 1 - Series HE ISOFLEX safety valve
NOTES
A complete set of spare cotter pins (not listed above)
is also recommended for proper maintenance of the
valve.
NOTES
1. Consumable spare parts: valve parts which
should be replaced as part of any disassembly.
(Discinserts must be replaced if seats are
damaged severely).
2. Repair spare parts: valve parts exposed to wear
and/or corrosion during normal operation.
They are in fluid flow paths and may require
replacement as part of any repair.
3. Insurance spare parts: valve parts exposed to
process or environmental wear and/or corrosion
and may require replacement as part of a major
repair.
Emerson recommends that sufficient inventory
of spare parts be maintained to support process
requirements. Always be sure to use genuine
Emerson parts to ensure continued product
performance and warranty.

3
CROSBY SERIES HE ISOFLEX®SELF-ACTUATED SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
1 INTRODUCTION
The design of the Crosby Series HE safety valve
with a balanced piston is shown in Figure 1.
This drawing shows the safety valve assembly
in cross section and covers the essential
elements of the valve.
NOTE
When specific information is required on the valves
supplied, approved drawings supplied with the valve
should be used.
Figure 1 shows the body (1A), the nozzle (1B),
the nozzle ring (3), guide ring (10), eductor (9),
the disc insert (5) which is designed to thread
onto the spindle point of the spindle assembly
(12) in a manner which allows the insert enough
freedom to properly position itself on the nozzle
(1B) and the disc holder (6), which is retained
between the disc insert (5) and the disc holder
retaining nut (7). The eductor (9) is retained
between the body (1A) and bonnet (17) by the
bonnet studs (18) and bonnet stud nuts (19).
The bonnet (17) contains the spring washers
(21 and 22) with load carrying bearing adapter
and thrust bearing (24 and 25), and the spindle
assembly (12), the lower end of which passes
through the disc holder and is positioned on the
bearing surface of the disc insert.
The adjusting bolt (26) is locked in place by the
adjusting bolt lock nut (27) on the top of the
bonnet within the cap.
Manual lifting means is provided by the lever
(30), lever pin (31), forked lever (33), forked
lever pin (34) and spindle nut (15).
2 FACTORY PREPARATION OF WELDED INLET
VALVES FOR SHIPMENT
All Crosby Series HE welded inlet safety valves
are equipped with hydrostatic test plugs and
shipped in two parts - valve body and valve
superstructure. This makes handling easier
for installation welding. Each portion ready for
shipment is illustrated in Figure 2.
The welded inlet Series HE safety valves are
prepared specially for shipment from the
factory.
After the safety valve is tested as a complete
assembly for set pressure and tightness, the
spring set compression is held by spacer
blocks under the bottom spring washer (21).
The safety valve superstructure is then
removed from the valve body. The two portions
are boxed and shipped separately.
The safety valve body as shipped to the site, is
tagged as follows:
Install and/or weld in place as required.
Prepare for hydrostatic test - see instruction.
Hydrostatic plug in place. Install O-ring and
backup ring prior to hydrostatic test.
Hold for assembly after hydrostatic test.
The safety valve superstructure as shipped to
the installation site is boxed separately from
the valve body and is tagged as follows:
3 PREPARATION OF VALVE FOR SERVICE
(initialinstallation)
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 valve parts. It is best to
leave valves in their shipment cases and store
them in a dry place under cover until they are
to be used.

4
CROSBY SERIES HE ISOFLEX®SELF-ACTUATED SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
Welding of body
The valve body should be welded to the boiler in
accordance with applicable code requirements.
The protective cover attached to the top of the
body during shipment should be left in place
until ready for the hydrostatic test of the unit.
Ifvisual inspection is necessary the cover may
be removed but should be replaced.
Top view - Body
FIGURE 2B - Valve superstructure as shipped
(see Note 2)
Hydro components (see Note 1)
FIGURE 2A - Valve body as shipped
NOTE 1 TO FIGURE 2A
Delivered with the body and packaged in small bag are
the following:
- One O-ring (for hydrostatic test)
- One backup ring (for hydrostatic test)
- One hydrostatic test plug pin
NOTE 2 TO FIGURE 2B
Delivered with the superstructure and packaged in a
small box are the following:
- Valve nozzle ring*
- Valve nozzle ring set screw*
- Valve guide ring set screw*
- Seal wires
* Marked with valve identification number.
NOTE
When the above parts are removed from their box, be
sure that the identification of parts to valve number is
maintained and that the parts are stored to facilitate
later recovery for assembly.
Installation
• Inlet piping
Many valves are damaged when first placed
in service because of failure to clean the
connections properly before installation.
It is essential that the valve inlet, the vessel
and the line on which the valve is mounted be
cleaned thoroughly of all foreign matter.
Safety valves should be mounted in a vertical
position, directly on the pressure vessel; the
nozzle should have a well-rounded approach
that provides smooth, unobstructed flow
between the vessel and the valve.
A safety valve should never be installed on a
fitting having an inside diameter smaller than
the inlet connection of the valve, as restricted
flow can cause faulty valve operation.
• Outlet piping
Discharge piping should be simple and
direct. Where possible, a short vertical pipe
discharging into the atmosphere is the most
desirable type of outlet piping and affords little
trouble.
Discharge piping should be designed so as not
to impose any loading on the valve. Excessive
discharge piping loads may cause seat leakage
or faulty valve operation. The inside diameter of
the discharge pipe must never be less than that
of the valve outlet.
Valve bodies are provided with pipe ½” NPT
thread openings for drains. These should be
connected to prevent any accumulation of fluid
in the valve body. In addition, it is recommended
that discharge piping also be drained to prevent
any accumulation of fluid.

5
K85280 2-218 91175 8-218
K285141 2-222 81563 8-222
M77583 2-225 81565 8-225
M285282 2-226 81576 8-226
P285283 2-232 81571 8-232
CROSBY SERIES HE ISOFLEX®SELF-ACTUATED SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
Hydrostatic testing
• Flanged and welded inlet safety valves
All welded inlet HE safety valves are prepared
for shipment from the factory with hydrostatic
test plugs and caps installed. When safety
valves are equipped with flanged inlets, it is
recommended that blank flanges be used for
hydrostatic test. However, if blank flanges are
not used and the valves are to be installed for
the hydrostatic test, Emerson recommends
the use of hydrostatic test plugs shown in
Figure 2 and Figure 3 on all flanged and welded
inlet safety valves.
FIGURE 3 - Hydrostatic test plug assemblies
Hydro plug
Pin
Hydro
cap
Backup
ring
O-ring
Nozzle
NOTE*
O-ring and backup ring to be installed after welding of
body to installation
View showing hydro plug assembled in valve nozzle
Note*
• Hydrostatic test procedure
Before imposing the hydrostatic test pressure
on the vessel, it is necessary to install the
O-ring and backup ring on the plug as
illustrated in Figure 3. The O-ring, backup ring
and the plug pin are shipped in a bag attached
within the body.
TABULATION OF HYDROSTATIC TEST PLUG O-RINGS AND BACKUP RINGS
Orifice Crosby O-ring part no. Manufacturers O-ring no. (size) Crosby backup ring part no. Manufacturers backup ring no.(size)
• Hydrostatic testing using hydrostatic test plugs
Referring to Figure 3, inspect the hydrostatic
plug O-ring groove. Install O-ring and backup
ring in the groove. Install the plug in the valve
nozzle (1B). Place the cap over the plug and
screw down hand tight. Install the test plug pin.
The valve is now ready for hydrostatic test.
• Hydrostatic testing using gag (see Figure 6)
Hydrostatic testing at pressure above the valve
set pressure using a gag is not recommended.
Observations should be made at the start of the
test that there is no leakage when pressure is
applied. If leakage is evident, tightening of the
cap will not reduce leakage but generally is
an indication that the O-ring or backup ring is
damaged and should be replaced.
The O-ring and backup ring materials are
suitable for a temperature of 450°F (232°C)
(and to 500°F (260°C) for a short period of
time), hence the boiling out operation can be
performed to a saturated steam pressure
corresponding to the temperature.
After completion of the hydrostatic test,
remove the hydrostatic test plug assembly
from the nozzle. To facilitate removal, place the
hydrostatic test plug pin in the plug extension.
Unscrew the cap, which will engage the plug
pin and exert an upward force as the cap is
turned, thus lifting the plug and rings from the
valve nozzle (1B).
Clean the nozzle bore and seat and inspect the
seating surface (if surface is damaged, lap per
instructions on pages 11 and 12).
4 INITIAL VALVE ASSEMBLY
• Cleaning and lubrication
All parts have been cleaned thoroughly prior to
initial assembly and the following areas have
been lubricated at the factory before and during
assembly.
They should be cleaned and relubricated as
required.
Recommended lubricants are Never-Seez[1]
and Dry Film Lubricant 321[2] or equivalent.
• Lubrication points (reference Figure 4 and
Figure 5)
- Nozzle to nozzle ring threads and guide ring
to eductor threads
- Adjusting bolt and bonnet threads
- Spindle point threads
- Spindle point tip
- Spindle rod threads
- Spring washer to adjusting bolt and spindle
point bearing surfaces
- Set screw threads
- All studs and nuts

6
CROSBY SERIES HE ISOFLEX®SELF-ACTUATED SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
CAUTION
Check the valve identification numbers and match
the proper superstructure to each valve body.
Figure 4 shows the location of valve identification
numbers.
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.
CAUTION
(Prior to installing superstructure) It is possible to
thread the adjusting ring too high onto the eductor
(9). If this happens when the valve is assembled,
the disc holder (6) will load on the guide ring (10)
lip before the disc insert (5) can come into contact
with the nozzle seat. To avoid this, the adjusting
ring should be positioned on the eductor so that
the holes in the adjusting rings are just below the
threads of the eductor - see Figure 5. No threads
should be visible through these adjusting ring
holes.
IMPORTANT
Do not permit any rocking motion of the spindle or
any part while lowering the superstructure into the
body. Any rocking motion could damage seats.
• Initial field assembly procedures
NOTE
It is recommended that upon completion of all
hydrostatic tests on new installations, a Crosby service
technician be present for assembly of the safety valves
(see page 14).
The following instructions should be followed:
- The valve superstructure assembly is
illustrated in Figure 2 and consists of the
bonnet, adjusting bolt, spring subassembly,
spindle, eductor, disc holder, guide ring and
disc insert, all of which are shipped as an
assembly. The nozzle ring and set screws are
packaged together in a box and delivered with
the superstructure. The contents of the box
are marked for identification.
- Although all parts have been inspected
thoroughly, cleaned, lubricated and protected
for shipment, the parts should be inspected
for evidence of foreign matter or damage
prior to installation. Special attention should
be given to the seating surface, disc insert(5)
and nozzle (1B). These seats should be free
from surface damage. If cleaning and/or
repair is necessary, refer to section 'Repair
procedures'.
FIGURE 4 - Lubrication and assembly
• Assembly of valve (spring compression retained)
Lubricate and install nozzle ring (3) onto nozzle
(1B). Leave the top of the nozzle ring level with
the nozzle seat.
Install the nozzle ring set screw into the base
and verify the fit and notch engagement. The tip
of the nozzle ring set screw should not touch
the nozzle ring. The nozzle ring should be free
to move side to side with approximately
1
/
32 inch
(.794 mm) clearance with set screw.
After the correct nozzle ring to set screw fit is
obtained, remove the set screw and raise the
nozzle ring
1
/
16 inch (1.59 mm) above the nozzle
seating surface.
Remove the forked lever pin (34), forked lever
(33) and cap (28).
With the superstructure lifted and the spindle
in the vertical position, inspect the eductor
to bonnet fit. Position the superstructure so
that the valve identification number stamped
on the bonnet is opposite the valve outlet
(see Figure 4).
Lower the superstructure slowly, carefully
align the eductor with the body bowl.
Install the bonnet stud nuts (19) on the bonnet
studs (18) and tighten uniformly.
After the bonnet nuts have been tightened, lift
up the spindle approximately ¼ inch (6.35 mm).
With the spindle in the lifted position, place a
screwdriver in the nozzle ring set screw hole
and turn the nozzle ring to the left (clockwise)
until the top edge of the nozzle ring is below
the nozzle seating surface. The location can
be checked by looking in through the adjusting
ring set screw hole while shining a light
through the nozzle ring set screw hole. Lower
the spindle assembly slowly until it bottoms.
IMPORTANT
Lift the spindle up and down gently to make
sure that the spindle and insert threads are not
engaged.
Installed
spacer
blocks
Fit should be
checked prior to
lowering super-
structure into
body
No threads should
be visible through
these holes
Nozzle
ring 1
/
16 “
(1.59mm)
above
nozzle set
* Lubrication points
Valve
identification
number
Guide ring
set screw
hole
Nozzle ring
set screw hole

7
K4 - 6 .008 - .012 (.203 -.305)
K25 - 6 .010 - .012 (.254 -.305)
M5 - 6 .010 - .012 (.254 -.305)
M25 - 6 .010 - .012 (.254 -.305)
P25 - 6 .010 - .012 (.254 -.305)
CROSBY SERIES HE ISOFLEX®SELF-ACTUATED SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
5 DESCRIPTION OF OPERATION
The operation of the Crosby Series HE safety
valve is as follows:
When the pressure in the valve inlet reaches
the set point, the valve will open with a sharp
pop with very little simmer or warn.
Full relieving capacity is reached within the
rated accumulation above set pressure.
Afterthe valve has popped, it will remain
open until the pressure under the valve has
decreased to the closing pressure, at which
point it will then close sharply.
CAUTION
The cotter pin head should be turned so that it fits between and into the retaining nut notch and makes
contact with the spindle. The split ends of the cotter pin should both be bent down.
CAUTION
The piston (2) should be seated within the housing
(1) before continuing. This seated position is
reached when the first notch on the piston (2) is
level with or below the top of the housing (1) as
indicated in Figure 7.
CAUTION
This device has a limited piston stroke that should
not be exceeded.
It is now necessary to remove the three spacer
blocks under the lower spring washer, thereby
transferring the spring load to the valve seats.
This is accomplished by unjacking the valve
using the hydraulic jacking device.
Referring to Figure 7, install the bonnet spacer
(5) on the bonnet (17). Position the jacking
device assembly by lifting it over the spindle
(12) and lowering it onto the bonnet spacer (5).
Lubricate the spindle threads with Never-Seez,
Molykote-G[3] or equivalent. Thread the spindle
adapter onto the spindle, turning until it comes
into contact with the jacking device assembly.
Attach the hand operated hydraulic pump (7)
and hose (8).
To raise the valve spindle, pressure is applied
to the jacking device assembly with the hand
operated hydraulic pump. This activates the
piston (2) which raises the lower spring washer,
compressing the spring.
FIGURE 5
Clearance between disc holder and retaining nut
Clean
surface
Retaining
nut
clearance
If the piston stroke is exceeded, the second
notch on the piston (2) will be above the top
of the housing (1) and hydraulic fluid will flow
from the bleed hole, located in the housing.
Ifhydraulic fluid is flowing from the bleed hole,
but the piston stroke has not been exceeded,
the O-rings (3 and 3A) and the backup rings
(4 and 4A) should be inspected for wear or
damage and replaced if necessary.
The spacer blocks may now be removed and
the spring load transferred to the valve seats by
releasing the pressure in the hydraulic pump
slowly. Remove the spindle adapter, jacking
device assembly and bonnet spacer.
Stand assembly on clean surface making certain that
the end of the spindle rotates freely on the disc insert
bearing surface (not loading on the insert threads).
Thread disc holder retaining nut (7) down until it
makes contact with the disc holder (6). Locatethe
hole in the spindle (12) relative to a notch on the
retaining nut. Back off the retaining nut by turning
counterclockwise to establish proper clearance.
(Clearance for particular orifice sizes are listed in the
table below). Install cotter pin through retaining ring
notch and spindle hole.
RETAINER NUT CLEARANCE VALUES
Orifice size Retaining nut notches Clearance inches(mm)
* Lubrication points
Referring to Figure 1, set the nozzle ring (3)
and guide ring (10). The nozzle ring location
and guide ring location are determined at
the factory and their locations are stamped
on the valve bonnet where the cap is seated.
Place a screwdriver in the nozzle ring set
screw hole and turn the nozzle ring to the right
(counterclockwise - positive direction [+]) until
it makes contact with the disc holder. Then turn
the nozzle ring to the left (clockwise - minus
direction [-]) to the factory setting. Repeat the
same procedure described above to set the
guide ring.
Lock the set screws (4 and 11) in place making
sure that the proper set screws are installed
and engaged in a notch and lock wire in place.
Install the spindle nut (15), spindle nut cotter,
cap (28) and lifting gear assembly before
tightening the cap set screws. Be sure that the
forked lever (33) is free to move from
1
/
16 inch
(1.59 mm) to ⅛ inch (3.18 mm) before coming
into contact with the spindle nut. If travel is
excessive, thread the spindle nut down. If there
is not enough travel, back off on the spindle nut.

8
K 5 6.8
K279.5
M11 14.9
M212 16.3
P222 29.8
6 SET PRESSURE TESTING AND ADJUSTMENT
The set pressure of a safety valve may be
checked by the following two methods with the
valve on the system:
Set pressure on system
• Air and hydraulic pressure devices
The first method is through the use of a set
pressure device which allows set pressure
setting of the safety valves on the system at
pressures below normal system operating
pressures. The air set pressure device method
is described in Test Procedure No. T-1652.
The hydraulic set pressure device method is
described in Instruction No. I-11288. Copies
of these manuals can be obtained on request
(see page 15).
CAUTION
All safety valves on the system except the valve
which is to be popped should be gagged (refer to
Figure 6). System pressure should be 70% of valve
set pressure before gagging. This is to prevent
added loads from being applied to the spindle due
to thermal expansion.
Gagging must be done with care not to overload
the spindle since considerable damage may occur
to the valve spindle, seat and other internals.
However, a minimum force should be applied to
ensure that the valve will not open.
CAUTION
The adjusting bolt (26) should never be turned
when the vessel pressure is near the set pressure
of the valve. Adjustments should not be made
until the pressure is 10% to 20% below the actual
popping pressure of the valve. This precaution
should be taken to avoid possible damage of
internal parts.
• System pressure
The second method of set pressure testing is
by raising the system pressure and popping the
valve. Set pressure testing using this method
will establish the valve set and closing pressure
(blowdown). Setting the valve with the air set
pressure device is recommended prior to
pressure testing. This allows the set point to be
established without raising and lowering system
pressure several times.
Prior to pressure testing, the following items
should be checked:
-
A pressure gauge with known accuracy
should be located on the system being
tested.
- Outlet piping should be anchored sufficiently
to prevent any vibrations while valve is
discharging; it should be directed and
there should be no obstructions to prevent
discharging.
- Set screws should be locked into the body
and lock wired.
- The tapped holes for drains in body should
be connected to a drain.
- Lifting gear should be fastened securely to
the valve.
- Communications should be set up between
control room and the system being tested.
Raise system pressure until the valve pops.
Record the popping and reseating pressure
(pressure at which the valve closes sharply).
If the valve pops before set pressure is reached
or it does not pop at set pressure, the following
steps for set pressure adjustment should be
taken:
CAUTION
Never make any ring adjustments with the
vessel under pressure without gagging the
valve properly. Care should be taken to use only
sufficient torque on the gag to hold the valve
closed. Overgagging may damage the valve
internals. (The gag is not recommended for
hydrostatic testing at pressures above valve set
pressure.)
CROSBY SERIES HE ISOFLEX®SELF-ACTUATED SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
FIGURE 6 - Valve gag
RECOMMENDED TORQUE VALUES*
Orifice size Torque (ft·lb) Torque (Nm)
Remove the forked lever and cap assembly.
The popping pressure may now be adjusted as
follows:
- Loosen the adjusting bolt locknut (27).
- If the valve has popped before the set
pressure stamped on the valve nameplate,
an increased set pressure is necessary.
Thisis obtained by turning the adjusting bolt
to the right (down).
- If the valve did not pop at set pressure,
decrease set pressure by turning the
adjusting bolt to the left (up).
- After each adjustment, the locknut should
be tightened securely to prevent loosening
of the bolt and the lifting gear reinstalled.
* For gagging to be applied when system pressure is 70% of valve set pressure

9
CROSBY SERIES HE ISOFLEX®SELF-ACTUATED SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
Nozzle ring and guide ring adjustment
The nozzle ring location and guide ring location
are determined at the factory and their locations
are stamped on the valve bonnet where the cap
is seated. However, if the desired blowdown is
not obtained, it will be necessary to adjust the
rings. The following steps should be taken:
FIGURE 7 - Crosby hydraulic jacking device
Bleed
hole
Piston stroke indicator
¼-18 NPT
CAUTION
Never make any ring adjustments with the vessel
under pressure without gagging the valve properly.
Care should be taken to use only sufficient torque
on the gag to hold the valve closed. Overgagging
may damage the valve internals.
• Guide ring adjustment
The guide ring (10) is the principal blowdown
control ring in the valve. To change the guide
ring position, remove the guide ring set screw
(11) from the body (1A). Insert a screwdriver
or similar tool and engage one of the notches
(these can be seen through the set screw hole).
The guide ring can then be turned to the right
or left as desired.
NOTE
Turning the guide ring to the right (counterclockwise)
decreases the blowdown. The guide ring should never
be turned more than five notches either way without
retesting the valve. After each adjustment always
replace, tighten and lock wire the set screw being
careful that its point engages a notch.
• Nozzle ring adjustment
The nozzle ring (3) is necessary in obtaining
the pop action of the valve. This ring setting is
determined carefully by factory test and rarely
needs any further adjustment. However, in case
the guide ring (10) adjustment does not give the
described operating characteristics under all
conditions of operation, the nozzle ring may be
adjusted to control the valve operation for very
fine adjustment.
The nozzle ring is adjusted by removing
the nozzle ring set screw (4) from the valve
body (1A). Moving the ring to the right
(counterclockwise) results in a strong 'pop'
action and will increase blowdown. Moving the
ring to the left (clockwise) lowers the ring and
decreases the blowdown. Warn or simmer may
result 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 lock wire the set screw, being careful that
its point engages a notch.
Whenever ring adjustments are changed, a
record should be kept of the number of notches
and the direction in which the ring was moved.
This will make it possible to return to the
original setting in case of error.
Parts list
1 Housing
2 Piston
3 O-Ring
3A O-Ring
4 Backup ring
4A Backup ring
5 Bonnet spacer
6 Spindle adapter
7 Hydraulic pump
8 ¼” Hose
12 Valve spindle
17 Bonnet
26 Adjusting bolt
27 Adjusting bolt nut
7 VALVE MAINTENANCE
The functioning and life of a safety valve
depends primarily on methods used in its
maintenance. For this reason, the following
recommended steps for maintenance should
be followed:
General information
When possible remove flanged inlet valves from
the system before dismantling. In any case,
there should be no system pressure when a
valve is either dismantled in place or removed
for shop repair.
Nozzle and guide ring set screws are
custom fitted to each valve and are not to be
interchanged. The spring washers are fitted to
each end of the spring. The spring and washer
are to be kept intact as a unit.
The piston (13) is retained on the spindle
assembly (12) by means of a piston ring (14).
The piston (13) has labyrinth grooves which
should be oriented downward toward the nozzle
when assembled on the spindle.
Before disassembly, spare parts and service
equipment (such as lapping compound, lapping
blocks and jacking gear) should be available.
After the valve has been adjusted to open and
close at the desired pressures, make sure the
adjusting bolt locknut and the set screws are
installed properly and tightened. If different ring
locations are obtained from testing, restamp the
valve bonnet with the new ring settings. Install
the cap, forked lever and
lever making sure
there is a
1
/
16 inch (1.59 mm) clearance between
the spindle nut and forked lever.

10
CROSBY SERIES HE ISOFLEX®SELF-ACTUATED SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
Valve disassembly
• Removal of the lifting gear
Remove the forked lever pin (34), forked lever
(33), cap (28), spindle nut cotter and spindle nut
(15).
• Recording of ring settings
Remove the nozzle ring set screw. Check the
setting of the nozzle ring by turning it to the
right (counterclockwise) counting the number
of notches turned until it makes contact with
the disc holder. Record the number of notches.
This location is given a minimum (-) (down)
notches from this contact position.
The guide ring should be turned to the right
(counterclockwise) until it makes contact with
the disc holder and raises the disc holder into
contact against the retaining nut. The guide
ring position is recorded as (-) (down) notches
from this contact position.
Disassembly (retaining spring compression)
If the valve is to be reconditioned without
retesting, the original set pressure can be
retained by use of a jacking device as shown in
Figure 7. This device is a service tool
that can
be obtained from Pentair (see page 15).
1. Measure from the bottom face of the bottom
spring washer to the bonnet flange top face
and record the dimension. Cut three pieces
of bar stock (1 inch [25.40 mm] diameter
minimum), ⅛inch (3.18 mm) longer than
the recorded dimension.
2. Install the bonnet spacer (5) on the bonnet
(17). Position the jacking device assembly by
lifting it over the spindle (12) and lowering
down onto the bonnet spacer (5).
CAUTION
The piston (2) should be seated within the housing
(1) before continuing. This seated piston is
reached when the first notch on the piston (2) is
level with or below the top of the housing (1) as
indicated in Figure 3.
CAUTION
Do not permit any rocking motion of the spindle
or of any parts while lifting the superstructure out
of the body. Any rocking motion could damage the
seats.
CAUTION
This device has a limited piston stroke that should
not be exceeded. If the piston stroke is exceeded,
the second notch on the piston (2) will be above
the top of the housing (1) and the hydraulic fluid
will flow from the bleed hole, located in the
housing. If hydraulic fluid is flowing from the bleed
hole, but the piston stroke has not been exceeded,
the O-rings (3 and 3A) and the backup rings (4 and
4A) should be inspected for wear or damage and
replaced if necessary.
3. Lubricate the spindle threads with Never-
Seez, Dry Film Lubricant 321, or equivalent.
Thread the spindle adapter onto the spindle
turning it until it comes into contact with the
jacking device assembly.
4. Attach the hand operated hydraulic pump (7)
and hose (8).
5. To raise the valve spindle, pressure is
applied to the jacking device assembly
with the hand operated hydraulic pump.
This activates the piston (2) which raises
the lower spring washer, compressing the
spring.
6. After the spring load has been taken up and
the valve has been jacked approximately
⅛ inch (3.18 mm), place the three
spacer blocks provided in step 1 of this
section, under the lower spring washer
(see Figure 2B).
7. The jacking device can now be removed
by releasing the pressure in the hydraulic
pump. Remove the spindle adapter, jacking
device and bonnet spacer.
8. Referring to Figure 1, loosen and remove
the bonnet stud nuts (19).
9. Using an eyebolt threaded onto the
spindle and a suitable lifting device, lift
thesuperstructure carefully straight up and
out of the body.
10. Lay the superstructure down so that
the spindle is in the horizontal position.
Caremust be exercised to prevent the
parts from being damaged while laying
thesuperstructure down.
11. Remove the eyebolt from the spindle and
slide the internals (disc holder, insert,
eductor, guide ring and spindle) carefully
outof the spring and bonnet assembly.

11
CROSBY SERIES HE ISOFLEX®SELF-ACTUATED SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
CAUTION
Never loosen the bonnet stud nuts (19) before
releasing spring tension with the adjusting bolt (26).
Disassembly
(without retaining spring compression)
If it is desired to disassemble the valve
completely and not retain the spring
compression, the following procedure should
be used:
1. Measure the distance from the top of
the adjusting bolt to the machine bonnet
surface. This measurement will be
necessary when the valve is reassembled.
2. Release spring tension by loosening the
adjusting bolt locknut (27) and then the
adjusting bolt(26).
3. Remove the guide ring set screw (11) and
the nozzle ring set screw (4).
4.
Loosen and remove the bonnet stud nuts (19) .
5. Using an eyebolt threaded onto the spindle,
lift the assembled superstructure straight
up and out of the body.
6. Lay the superstructure down so that
the spindle is in the horizontal position.
Caremust be exercised to prevent the
parts from being damaged while laying
thesuperstructure down.
7. Remove the eyebolt from the spindle and
slide the internals (disc holder, insert,
eductor, guide ring, and spindle) carefully
out of the spring and bonnet assembly.
CAUTION
Do not permit any rocking motion of the spindle
or of any parts while lifting the superstructure out
of the body. Any rocking motion could damage the
seats.
8 REPAIR PROCEDURE
When the valve is dismantled completely,
examine all parts for signs of wear, damage or
corrosion to determine if any replacement parts
are required. Particular care should be used to
examine the following parts:
• Insert (5)
- Seat (see Figure 8 for minimum dimension)
- Spindle bear surface on the inside of the
insert
- Land outside diameter which interfaces with
the disc holder
Lapping of the valve seats
Good seating surfaces on the nozzle (1B) and
disc insert (5) are of the greatest importance
when reconditioning safety valves.
The seats should always be flat and free from
surface scratches.
• Lapping block (see Figure 9)
This is made of a special grade of annealed cast
iron, perfectly flat on both sides. It is essential
that it remain flat to produce a truly flat seating
surface. In checking the lapping block and for
restoring flatness after its use, a lapping block
reconditioner should be used.
• Lapping block reconditioner (see Figure 9)
This is also made of a special grade of annealed
cast iron, machined and lapped on the side
which has small squares. This is the surface on
which the lapping blocks are reconditioned.
• Nozzle (1B)
- Seating surface
- Seat step (see Figure 8 for minimum
dimension)
- Outside diameter of lands that guide in
theeductor
- Inside diameter where the disc insert guides
- Inside diameter of eductor (9) where the
piston (13) guides
• Spindle (12)
-
At bottom spring washer (21) bearing surface
- Where the spindle point bears on disc insert (5)
- The surfaces that pass through the
adjusting bolt (26) upper and over spring
washers (21 and 22) and disc holder (6).
If replacement parts are required, refer to
paragraph 'Spare parts'.

12
(A)
(B)
'A'
K .006 (.152)
K2.006 (.152)
M.006 (.152)
M2.006 (.152)
P2.010 (.254)
K .005 (.127)
K2.006 (.152)
M.007 (.178)
M2.007 (.178)
P2.010 (.254)
Spindle (12)
Nozzle
Bonnet (17)
Adjusting bolt (26)
1.a Check ring settings
FIGURE 8 - Minimum allowance dimensions
When the 'A' Dimension is less than shown
above, the nozzle seat should be remachined.
Orifice size
Minimum 'A' dimension
inches (mm)
Insert
'B' min.
after
lapping
When the 'B' Dimension is less than shown
above, the insert should be replaced.
Orifice size
Minimum 'B' dimension
inches (mm)
• Lapping compounds
Experience has proven that three grades of
compound - medium, fine and polish - will
condition almost any damaged valve seat
properly, unless, of course, remachining
to establish the seat contour is necessary.
Amedium coarse compound may be used for
fast cutting as a first operation after machining,
if desired.
The lapping compounds shown overleaf, or
their commercial equivalents, are suggested.
• Lapping procedures
Different individuals have different methods
of lapping valve seats, but certain essential
steps must be taken to get satisfactory results.
Thefollowing procedure is suggested for
lapping of valve seats:
- Never lap the disc insert against the
nozzle. Lap each part separately against a
cast iron lapping block of the proper size.
Theseblocks hold the lapping compound in
their surface pores, but must be recharged
and reconditioned frequently.
- Check the lapping block frequently on a
good lapping block conditioner to make
certain that it is perfectly flat on both sides.
If considerable lapping is required, spread
a thin coat of medium lapping compound on
the block. After lapping with this compound,
lap again with a fine compound using a new
lapping block surface. The first step can be
omitted unless much lapping is called for.
Next, lap again using a polish compound.
- Lap the block against the seat.
Neverrotatethe block continuously, but use
an oscillating movement.
- When all nicks and marks have
disappeared, remove all the compound from
the block and seat. Apply polish compound
to another block and lap the seat with this.
As the lapping nears completion, only the
compound left in the pores of the block
should be present. This should give a very
smooth finish. If scratches appear, the
cause is probably dirty lapping compound.
These scratches should be removed by
using compound free of foreign material.
- Extreme care should be taken throughout to
make certain that the seats are kept flat.
CROSBY SERIES HE ISOFLEX®SELF-ACTUATED SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS

13
CROSBY SERIES HE ISOFLEX®SELF-ACTUATED SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
Top lapping
surface
Lapping block to
be squared up
Bottom rough
surface do not use
Motion shown by
dotted lines
Lapping block resurfacing plate
Lapping block
LAPPING COMPOUNDS
Abrasive Grit size Average micron size Description Manufacturer’s trade name or equivalent
Silicon carbide 320 31 Medium coarse U.S. products no.2F Crystolen
Silicon carbide 400 22 Medium U.S. products no.3F Crystolen
Silicon carbide 600 16 Fine U.S. products no.A-600 Crystolen
Hard aluminia or aluminum oxide 900 9Polish U.S. products no.38-900-A
FIGURE 9
Hyprez[3] Diamond Lapping Compound 3(L) or
6(L) is used in conjunction with a lapping
and
cleaning thinner, Hyprez Hyprelube no. 236
, and
should be used as described in the following
procedure:
1. Clean lapping block using acetone or
apply cleaning thinner, Hyprelube no.236.
Wipewith a clean, dry, soft cloth or
Kimwipe[4] (or equivalent) prior to applying
lapping compound.
2. Apply dots of Hyprez Diamond Lapping
Compound 3(L) or 6(L) on the lapping
block approximately one-half to one
inch apart (not less than four per block)
circumferentially on the face of the lapping
block. Apply a drop of lapping thinner
Hyprelube no. 236 to each dot of compound.
3. Lap the valve seat, keeping the lapping
block against the seat and applying slight
downward pressure. During the operation
the lapping compound may begin to get stiff
and movement of the lapping block more
difficult. Remove lap from lapped surface
and add a few drops of the Hyprelube
lapping thinner to the lapping block. Replace
on surface being lapped and continue to
rotate exerting no downward pressure.
CAUTION
The lapping compound cuts very quickly.
Therefore the lapping block must be checked
periodically to be sure that the block is flat and
that a groove is not worn in the lapping block due
to the lapping operation.
4. While lapping, the lapping block should
slide smoothly over the surface being
lapped. Indications of roughness in lapping
are indicative of contaminated compound.
Thelapping block and seating surface
should be cleaned thoroughly with thinner
and the lapping operation repeated.
5. Continue this for approximately one minute
then remove the lapping block and clean
lapped surface and the block with thinner
and wipe with a clean, dry, soft cloth or
Kimwipe.
6. If the surface is still in an unsatisfactory
condition, change the lapping block and
repeat the above process until a satisfactory
surface is obtained.
7.
After final lapping, clean the seating area with
the lapping thinner and then with acetone
(orequivalent) and wipe clean with cotton.
Micro-finishing of valve seats
Valve seats should be lapped to a micro-inch
finish using special compounds and the lapping
procedure herein outlined. Prior to micro-
finishing, the valve seats should be lapped flat
and to a fine surface finish in accordance with
lapping procedures discussed above.

14
CROSBY SERIES HE ISOFLEX®SELF-ACTUATED SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
9 VALVE ASSEMBLY
Assembly of valve
(retaining spring compression)
See section 'Assembly of valve (retainingspring
compression)'.
Assembly of valve
(without retaining spring compression)
NOTE
All lubrication points discussed in this section are
shown in Figures 3, 4 and 5.
Lubricate and thread the disc holder retaining
nut (7) onto spindle (12). With the retaining nut
in its highest position, install the disc holder
(6) over lower end of the spindle. Lubricate the
insert bearing surface and insert threads and
thread the disc insert (5) onto the end of the
spindle until it drops off the bottom thread and
rotates freely on the insert bearing surface.
CAUTION
Care should be used in the assembly operation to
insure against disc insert and nozzle seat damage.
CAUTION
The guide ring can be threaded too high onto
the eductor. If this happens, when the valve is
assembled the disc holder will load on the guide
ring lip before the insert can come into contact
with the seat.
CAUTION
With the superstructure lifted and the spindle in
the vertical position, inspect the eductor to bonnet
fit. Be sure eductor is fully seated in the bonnet.
To establish clearance between the disc holder
and retaining nut refer to Figure 5.
Install eductor (9) by lifting the eductor over
the spindle assembly (12) and lowering it into
position on the disc holder (6). The guide ring
(10) may be now screwed onto the eductor.
To avoid this, the guide ring should be positioned
so that the holes in the guide ring are just
below the threads on the eductor. No threads
should be visible through these holes. Stand the
assembly on the guide ring face, with spindle
vertical, on a clean work surface.
Lubricate and install the thrust bearing (25)
and bearing adapter (24) for the top spring
washer and lubricate the bottom spring washer
(21). Place the spring and washer assembly in
position within the bonnet.
Install the adjusting bolt lock nut (27) onto
adjusting bolt (26) by screwing it all the way to
the top. Lubricate the entire threaded portion
of the adjusting bolt and the bonnet threads
carefully and screw the adjusting bolt part way
into the bonnet.
Using a suitable lifting device, (hoist, chain fall,
etc.) lift the spring/ washer and bonnet assembly
up over the spindle assembly and lower carefully
into place.
Lower the superstructure slowly, align the
eductor carefully with the body bowl.
IMPORTANT
Do not permit any rocking motion of the spindle
or of any parts while lowering the superstructure
into the body. Any rocking motion could damage
seats.
Lubricate and install bonnet nuts (19) on bonnet
studs (18) and tighten uniformly.
After bonnet nuts have been tightened, lift the
spindle approximately ¼ inch (6.35 mm) to
free nozzle ring. With the spindle in the lifted
position, place a screwdriver in the nozzle ring
set screw hole and turn the nozzle ring to the
left (clockwise) until the top edge of the nozzle
ring is below the nozzle seating surface.
The location can be checked by looking through
the adjusting ring set screw hole while shining
a light through the nozzle ring set screw hole.
Lower the spindle assembly slowly until it
bottoms. The nozzle and disc insert seating
surfaces are now in intimate contact.
IMPORTANT
Lift the spindle up and down gently to make
sure that the spindle and insert threads are not
engaged.
Lubricate and install nozzle ring (3) onto nozzle
(1B) making sure the nozzle ring is above
the
nozzle seating surface (approximately
1
/
16 inch (1.59 mm)). (If new nozzle ring or set
screw is used, refer to section 'Assembly of
valve (retaining spring compression)' for set
screw fit).
Using an eyebolt threaded onto the spindle
and a suitable lifting device, lift the assembled
superstructure.

15
CROSBY SERIES HE ISOFLEX®SELF-ACTUATED SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
Tighten the adjusting bolt a few flats and check
the guide and nozzle rings to be sure they are
free. The adjusting bolt may now be tightened to
achieve desired set pressure.
Tighten the adjusting bolt until the distance is the
same as that recorded in step 1,' Disassembly
(without retaining spring compression)' before
the valve was dismantled.
Unless considerable lapping or machining has
been done, the set pressure should be almost
the same as before reconditioning.
Regardless, the set pressure of the valve should
be re-established using the methods described
in section 'Set pressure testing and adjustment'.
Having recorded the ring positions at
disassembly, return rings to recorded location.
Touch nozzle/guide ring with disc holder and
turn down (left)(minus) to recorded position at
disassembly. Lock set screws in place making
sure that set rings are engaged in a notch.
Replace the spindle nut (15), spindle nut cotter
cap (28) and lifting gear assembly.
10 SPARE PARTS
Emerson recommends spare parts as shown
on the outline drawing, Figure 1.
When ordering spare parts the valve assembly
number should be given together with part
number, valve size and style. On the valve
nameplate (location of name shown in
Figures1 and 2), the valve assembly number is
shown as a 'Shop number'. Any Emerson sales
office or representative can expedite your spare
parts requirements.
11 FIELD SERVICE RECOMMENDATIONS
Emerson operates an extensive field service
organization capable of adjusting, setting, and
maintaining Crosby valves worldwide. Service
technicians are located throughout the world
for fast response to our customers’ needs.
Service technicians are factory-trained and
are experienced in servicing safety valves. It is
strongly recommended that on new installations,
a Emerson service technician be present for
assembly and testing of safety valves.
Service equipment available
All service equipment mentioned in this
instruction is available for purchase or rental.
Any Emerson sales office, representative or
service manager can expedite your service
equipment requirements.
NOTES
[1] Manufactured by Bostik Corporation
[2] Manufactured by Dow Corning Corporation
[3] Manufactured by the Hyprez Division,
EngisCorporation
[4] Manufactured by Kimberly Clark Corporation

16
CROSBY SERIES HE ISOFLEX®SELF-ACTUATED SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
12 MAINTENANCE EQUIPMENT Air (ASPD) and Hydraulic (HSPD) - set
pressure devices
The set pressure of safety valves may be
determined without raising system pressure to
the popping pressure of the valves by using a
Crosby valve set pressure device which may be
rented or purchased.
The apparatus consists of a lifting device
mounted on the bonnet and connected to the
spindle of the safety valve. The differential
force required to open the safety valve when
the system (steam) pressure is less than the
valve set pressure is applied by the operator.
Thedifferential force at which the valve opens
is determined and the safety valve set pressure
is calculated from this measurement.
Contact the factory.
Reseating machines
Crosby valve reseating machines will
remachine the nozzle seats in place without
removing the safety valve from the installation.
Form cutters are used to cut a new seat to
exact dimensions. Reseating machines, cutters
and auxiliary equipment may be rented or
purchased.
Contact the factory.
Reseating machines Air set pressure device Hydraulic set pressure device
Jacking devices
When a safety valve is to be disassembled and it
is desired to retain spring compression, i.e., the
set pressure, a mechanical or hydraulic jacking
device may be used. Jacking devices are used
to lift the bottom spring washer sufficiently to
allow the disc or disc insert to lift clear of the
nozzle (permitting the entire bonnet assembly
to be removed). Jacking devices may be rented
or purchased.
Contact the factory.
Neither Emerson, Emerson Automation Solutions, nor any of their affiliated entities assumes responsibility for the selection, use or maintenance of any product.
Responsibility for proper selection, use, and maintenance of any product remains solely with the purchaser and end user.
Crosby is a mark owned by one of the companies in the Emerson Automation Solutions business unit of Emerson Electric Co. Emerson Automation Solutions, Emerson
and the Emerson logo are trademarks and service marks of Emerson Electric Co. All other marks are the property of their respective owners.
The contents of this publication are presented for informational purposes only, and while every effort has been made to ensure their accuracy, they are not to be construed
as warranties or guarantees, express or implied, regarding the products or services described herein or their use or applicability. All sales are governed by our terms and
conditions, which are available upon request. We reserve the right to modify or improve the designs or specifications of such products at any time without notice.
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