Emerson CROSBY Installation, Maintenance And Adjustment Instructions

CROSBY STYLE JCE SAFETY VALVE

InstallatIon, MaIntenance and adjustMent InstructIons

1 INSTALLATION

The valve must be installed with its main axis
perpendicular either on pipework or directly on
to the pressure vessel. The branch leading to
the valve shall be of sufficient size to prevent
a pressure drop in excess of 3% of the set
pressure when the valve is discharging its rated
capacity.

1.1 Drainage

If liquid can collect on the discharge side of the
valve, the drain plug (42) should be removed
and drain pipework connected so that the liquid
can be discharged at a point where it will not
cause injury to anyone.

1.2 Discharge pipework

In no case shall the nominal bore of the
discharge pipework be less than the nominal
bore of the valve outlet.
Except for balanced bellows valves, pipework
should be as short as possible, and of sufficient
size to limit the pressure drop through the
pipework to 10% of the set pressure.
The pipework should be suitably supported
so as not to impose an excessive load on the
valve, and consideration should be given to the
reaction due to the valve discharging its rated
capacity.

1.3 Preparing for installation

Remove all packing material. Check that the
set pressure and other details on the valve
nameplate are correct. Fit an inlet gasket and
ensure that it is properly located so that it does
not impede the flow to the valve. Connect up the
discharge piping, ensuring that an outlet gasket
is properly located.
Note: Fluid discharged from the bonnet vent
hole in the event of bellows failure on Balanced
Bellows valves is usually discharged to
atmosphere. If this fluid is toxic or inflammable,
it must be piped away to a safe place, however
atmospheric pressure within the casing must
be maintained.
Note: Pipework leading to the valve should
be thoroughly cleaned to remove any foreign
matter, as this would cause the valve to leak if
trapped between the seat (4) and disc (5).

2 PRESSURE ADJUSTMENT

The valve has been factory set, but if it is found
necessary to make pressure alterations, it
is desirable to remove the valve from the
installation and use a suitable test rig. If this
cannot be done, the pressure may be altered
in situ by removing the cap (3), retaining the
compression screw in position by means of the
flats provided and slackening off the locknut
(13). The set pressure of the valve may be
increased by turning the compression screw
(12) in a clockwise direction, or decreased by
turning the screw in anti-clockwise direction.
Note: On valves with packed or marine caps the
cap may be removed by following the procedure
in4.4 or 4.5.
The set pressure should be checked by bringing
the pressure within the vessel or pipework
up to the required level gradually. A pressure
gauge must be installed so that the pressure
may be checked.

3 MAINTENANCE

Before any maintenance work is carried out, all
pressure should be exhausted from the system.
If the work cannot be carried out in a satisfactory
manner by competent personnel, the valve
should be returned to the factory for service.
It is not always possible to carry out
maintenance work at the site, and we suggest
that the valve should be removed from the plant
and taken to a workshop.

4 DISMANTLING

4.1 All valve types - Refer to figure 1

Unscrew the cap (3), if a packed or marine type
cap is fitted refer to sections 4.4 and 4.5. Slacken
the locknut (13) and remove all compression
from the spring (22) by turning the adjusting
screw (12) anti-clockwise. It is recommended
that the adjusting screw (12) is marked before
removal so that the valve can be approximately
reset to the correct pressure on reassembly.
Slacken the body nuts (19) and remove
the cover(2). Remove the spindle (10)
from the guide plate (9), complete with the
lower spring plate(11) as an assembly.

Thelowerspringplate(11) may then be lifted off
its split collar (69) and removed from the spindle
(10). Care should be taken not to lose the split
collar (69). If the valve is an 80mm or 100mm
high pressure model the 4 nuts (21) holding
the cover spacer (68) to the body (1) should be
removed and the cover spacer (68) lifted away
from the guide plate (9). The guide plate (9)
may now be removed from the body (1). It is not
recommended to release the guide plate (9) by
inserting a tool in the seat bore (4) as damage to
the disc (5) and seat (4) will result.
Note: Care must be taken when removing the
guide plate (9) not to damage the bellows unit
(23) on balanced bellows valves.

4.2 Conventional valve - Refer to figure 1

4.2.1 Remove the disc assembly from the
seat(4), being careful not to lose the
ball (31). Examine the disc (5), re-lap as
necessary. If the valve is a resilient seated
model refer to next section.

4.2.2 Resilient seated valve - Refer to figure 4.

The resilient seat (53) may be replaced,

if necessary, by removing the circlip (65)
from the disc assembly along with the
retaining plate (66).

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CROSBY STYLE JCE SAFETY VALVE

InstallatIon, MaIntenance and adjustMent InstructIons

4.3 Bellows valve - Refer to figure 1

4.3.1

Remove the bellows unit (23) complete

with disc assembly from the seat (4), being
careful not to lose the lift stop (81) and ball
(31). If the valve is a resilient seated model
follow the procedure outlined in4.2.2. to
remove the resilient seal; this must be done
before the bellows unit (23) is removed.

4.3.2 If the bellows unit (23) requires replacing,
this will be supplied welded to the disc.
The disc will be supplied fully lapped in
protective wrapping. Only use factory
supplied bellows units.

4.4 Marine cap - Refer to figure 2

To remove the marine cap (3) first remove
the fulcrum pin (56) from the lever (73) using
a suitable tool as a drift. The lever (73) may
now be withdrawn from the cap (3). Slacken
the grub screw (75) and unscrew the marine
cap (3). It is recommended that the spindle
nut (61) should be marked prior to removal so
that the correct position can be attained upon
reassembly. Remove the spindle nut (61) and
the spindle washer (83).
Further dismantling of the valve is achieved by
following the procedure outlined in4.1.

4.5. Packed cap - Refer to figure 3

To remove the packed cap (3) first undo the
gland (57). It may be necessary to ease the
eccentric shaft (70) outwards during this
operation to ensure that the gland (57) can
be withdrawn from the cap (3). The lever
assembly may now be withdrawn from
the cap complete with gland packing (58).
Thetensionpin(35)should be released from
the lever (73) by using a suitable tool as a drift.
The lever (73), gland (57) and gland packing(58)
may now be removed from the eccentric
shaft(70).
Note: It will be necessary to fit new gland
packing (58) on reassembly.
The cap (3) may now be unscrewed from the
bonnet (2). It is recommended that the lock
nut (82) should be marked prior to removal so
that the correct position can be attained upon
reassembly. Unscrew the locknut (82) and the
spindle nut (61).

Further dismantling of the valve is achieved by
following the procedure outlined in4.1.

5 EXAMINATION AND RECONDITIONING

5.1 Disc

Examination of the disc (5) will reveal whether it
requires re-lapping. The disc may be re-lapped,
using a flat cast iron lapping plate. Using a
fine lapping paste, without applying excessive
pressure, lap the disc until all imperfections
have been removed from the seating face. If
the disc is too badly damaged to relap fit a new
disc.

5.2 Seat

Examination of the seat (4) will reveal whether it
requires relapping. The seat (4) may be lapped
in situ in the body (1) using the same lapping
plate as for the disc (5) and following the same
procedure. If the seat face is too badly damaged
to re-lap it must be remachined. The maximum
amount of metal it is allowable to remove is
3mm. If this is exceeded, the valve must be
returned to the factory for a new seat fitting.
Having been machined the seat (4) should be
re-lapped as previously described.
Note: Ensure all lapping paste is removed from
the seat (4) and the disc (5) before reassembly.

5.2.1 Seat replacement

In the event of complete seat

replacement being required, the existing
seat must be machined out, and an
oversize seat obtained from the factory.
Donotomitremoval and replacement of
the seat security pin.

Machine out seat recess diameter to

give interference at ambient conditions
according to the following table.

5.2.2 Procedure for fitting new seat

Remove existing seloc pin. Remove /

machine seat from body. Re-machine
body to dimensions in table above. Coat
body recess with ‘Boss White sealant’.
Insert seat into liquid nitrogen and leave
until temperature has been reduced to
minus 196°C. Remove seat from liquid
nitrogen and insert into body recess,

using tools provided Hammer the seat
into body ensuring that the seat properly
‘bottoms’ in the recess. Allow assembly
to reach room temperature.

5.2.3 Seat change procedure

Drill into seat ‘B’ depth as shown below

through existing hole in body, and fit new
‘Seloc’ pin. Cut and dress pin flush with
body. (Note that body will be received
drilled)

Valve size Body dimensions (inch) Seat dimensions (inch) Interference (inch)

1” 1.3008 / 1.2992 1.3039 / 1.3029 0.0037 / 0.0021
1¼” 1.5764 / 1.5748 1.5795 / 1.5785 0.0047 / 0.0021
1½” 1.9701 / 1.9685 1.9739 / 1.9729 0.0054 / 0.0028
2” 2.3642 / 2.3622 2.3690 / 2.3678 0.0068 / 0.0036
2½” 3.1516 / 3.1496 3.1576 / 3.1564 0.0080 / 0.0048
3” 3.7425 / 3.7401 3.7499 / 3.7485 0.0098 / 0.0060
4” 4.7268 / 4.7244 4.7358 /4.7344 0.0114 / 0.0076

DN 25 32 40 50 65 80 100

‘A’ pin dia x length prior to cut off ø3 x 18 ø3 x 24 ø3 x 28 ø3 x 36 ø3 x 36 ø3 x 40 ø3 x 45
‘B’ pin/drill depth 1 1.5 2.5 2.5 2.5 2 2.5

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CROSBY STYLE JCE SAFETY VALVE

InstallatIon, MaIntenance and adjustMent InstructIons

5.3 General examination

Ensure that the bore of the guide plate (9) is
in good condition, and that the spindle (10)
where it passes through the guide (9) and the
adjusting screw bush (77) is free from any
surface defects. Ensure that the adjusting
screw bush (77) is not worn. Examine the ball
location points in the disc (5) and the spindle
(10) and ensure that they are of a clean smooth
finish. Examine the ball (31) for surface
imperfections and replace if damaged. If the
spring is corroded it should be replaced.

5.4 Resilient seal

If the resilient O-ring (53) is damaged it should
be replaced. The seal is removed from the disc
(5) by following the procedure outlined in4.2.3.

5.5 Bellows

If the bellows unit is damaged, distorted or
corroded in any way it should be replaced.

6 REASSEMBLY

6.1 Conventional metal seated valves

6.1.1 Apply grease to both ball and adjusting
screw. Place the ball (31) in position on
the disc (5) and position the disc assembly
onto the seat (4). Place new gasket (27)
onto the guide recess in the body.

6.1.2 Fit the spindle (10) on to the ball (31) and
slide the guide plate (9) into position in
the body recess. Ensure that the spindle
(10) is free to move. Fit the split collar (69)
onto the spindle (10) and slide the lower
spring plate (11) into position. Ensure that
the spring plate (11) is fully located on the
split collar. Place a new gasket (27) onto
the guide plate (9).

If the valve is an 80mm or 100mm high

pressure model the cover spacer (68)
should be positioned onto the guide plate
(9) and the 4 nuts (21) tightened. A new
gasket should be positioned on top of the
spacing piece.

Place the spring (22) onto the lower

spring plate (11) and fit the upper spring
plate (11) onto the spring (22). Lower the
bonnet (2) over the spindle (10) and onto
the guide plate (9). Tighten down fully the
4 nuts (19). Slide the adjusting screw (12)
over the spindle (10) and screw it into the
bonnet (2). Set the adjusting screw (12) to
its original position and secure with the
locknut (13).

6.2 Bellows metal seated valves

6.2.1 Place the ball (31) in position on the disc
(5) and the lift stop (81).

6.2.2 Place a new gasket (27) onto the body
recess and position the spacing piece
(47) onto the body (1). Position the disc/
bellows assembly onto the seat (4) and
ensure that the bellows flange locates
squarely into the spacing piece recess.
Follow the procedure outlined in6.1.2
to further assembly the valve. It is
very important that an effective seal is
achieved between the bellows flange and
the guide plate.

6.3 Resilient valves

Place the 0-ring (53) into position on the disc (5)
along with the retaining plate (65). Secure the
assembly with the circlip (66) ensuring that the
retaining plate (65) is centrally located on the
0-ring (65).
Follow the relevant procedure outlined in6.1.1
or 6.2.1 to further re-assemble the valve

6.4 Pressure Setting

The set pressure on gas/vapor is defined where
audible discharge occurs. On liquid valves
this is defined where the first steady stream
of liquid occurs. In both cases, the pressure
gauge measuring inlet pressure will stop rising
when set pressure is reached.
Ensure that the internal surfaces of the valve
inlet and test rig are clean and mount the
valve securely on the test rig. Set the valve to
the required pressure using air or nitrogen
for valves intended for gas or vapor service.
Inhibited water should be used for valves
intended for liquid duty. Adjust the adjusting
screw (12) until the required set pressure is
achieved and pull up the locknut (13). Finally
check that the set pressure has not altered.
Refit the cap (3) using a new gasket (28) if
applicable. To reassemble the packed and
marine caps reverse the procedure described
in4.4 or 4.5.

7 SUPPLEMENTARY NOTES

7.1 Danger can emanate from the incorrect

installation, maintenance and adjustment
of this product. For this reason only
qualified persons are permitted to work
on the product within the guidelines
supplied by the manufacturer.

7.2 Failure to adhere to these instructions
will invalidate any CE marking.

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CROSBY STYLE JCE SAFETY VALVE

InstallatIon, MaIntenance and adjustMent InstructIons

PARTS LIST

Item nr. Part name

1 Body
2 Bonnet
3 Cap
4 Seat
5 Disc
9 Guide plate
10 Spindle
11 Spring plate
12 Adjusting screw
13 Locknut
18 Body stud
19 Body nut

(H)

20

(H)

21
22 Spring

(B)

23
27 Body/bonnet gasket
28 Cap gasket
31 Ball
33 Nameplate
34 Nameplate pin
41 Warranty seal
42 Drain plug

(B)

47
62 Seat pin

(H)

68
69 Split collar
77 Adjusting screw bush

(B)

81

Cover stud
Cover nut

Bellows unit

Spacing piece

Cover spacer

Lift stop

FIGURE 1

Standard screwed cap

C1 Conventional
C2 Bellows type

Minimum withdrawal
allowance

Bellows type

B.S.P.
atmospheric
vent

N.P.T.
Body drain (remove
plug and pipe away
if required)

NOTE

B = denotes only used on bellows type valves
H = denotes only used on high pressure type valve

Dimensions (mm) unless otherwise stated

25 x 40 32 x 50 40 x 65 50 x 80 65 x 100 80 x 125 100 x 150

A 100 110 115 120 140 160 180
B 105 115 140 150 170 195 220
C1 410 455 570 615 725 825/925 H 925/1030 H
C2 445 490 605 665 785 865/965 H 955/1060 H
D 85 85 125 125 155 155 180
E ⅜” ⅜” ½” ½” ¾” ¾” ¾”
F ¼” ¼” ¼” ¼” ¼” ⅜” ⅜”
WT 8-5 14-0 20-0 30-0 42-5 64-5 86-0

NOTE

Weights (kg) given are approximate for cast iron valves.
H = denotes high pressure valve longer bonnet, spring and spindle.

Conventional

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CROSBY STYLE JCE SAFETY VALVE

InstallatIon, MaIntenance and adjustMent InstructIons

OPEN TYPE EASING GEAR

Valves which are used for steam or compressed
air are normally fitted with open type easing
gear.
This type of easing gear can also be used on
other fluids where a small escape of the fluid
to atmosphere, when the valve is discharging,
is not objectionable. It is normally fitted on
conventional type valves only. The purpose of
the easing gear is to check that the valve can
operate freely.

PACKED EASING GEAR

Alternatively packed easing gear can be
supplied. This is used when the fluid can not
be allowed to escape to atmosphere except
through the outlet connection, but where it
is necessary to check that the valve is free to
operate.

PARTS LIST

Item number Part name

3 Open type bonnet
56 Fulcrum pin
61 Spindle nut
73 Marine easing lever
75 Grub screw
83 Spindle washer

PARTS LIST

Item number Part name

3 Packed type bonnet
28 Cap gasket
35 Tension pin
57 Gland
58 Gland packing
61 Spindle nut
70 Eccentric shaft
73 Packed easing lever
82 Spindle lock nut

FIGURE 2
Open (marine) easing gear

FIGURE 3
Packed easing gear

RESILIENT SEAT

The standard construction using metal-to­metal seats lapped to IMI Bailey Birkett’s high
standard is suitable for most applications.
Elastomeric seals are supplied as conditions

PARTS LIST

Item number Part name

5 Resilient disc
53 O-ring seal
65 Circlip
66 Retaining plate

FIGURE 4
Resilient disc

dictate.

O-ring material Temp. range

A. Viton -30 to 200°C
B. Nitrile -40 to 100°C
Other materials may be available upon request

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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