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INSTALLATION / OPERATION / MAINTENANCE
Pressure Relief Control
DESCRIPTION
The CRL Pressure Relief Control is a direct acting, spring loaded,
diaphragm type relief valve. It may be used as a self-contained valve or
as a pilot control for a Cla-Val Main valve. It opens and closes within
very close pressure limits.
INSTALLATION
The CRL Pressure Relief Control may be installed in any position. The
control body (7) has one inlet and one outlet port with a side pipe plug
(24) at each port. These plugs are used for control connections or gauge
applications. The inlet in the power unit body (6) is the sensing line port.
A flow arrow is marked on the body casting.
OPERATION
The CRL Pressure Relief Control is normally held closed by the force of
the compression spring above the diaphragm; control pressure is applied
under the diaphragm.
When the controlling pressure exceeds the spring setting, the disc is lifted
off its seat, permitting flow through the control.
When controlling pressure drops below spring setting, the spring returns
the control to its normally closed position.
ADJUSTMENT PROCEDURE
The CRL Pressure Relief Control can be adjusted to provide a relief setting at any point within the range found on the nameplate.
Pressure adjustment is made by turning the adjustment screw (9) to vary
the spring pressure on the diaphragm. Turning the adjustment screw
clockwise increases the pressure required to open the valve.
Counterclockwise decreases the pressure required to open the valve.
When pressure adjustments are complete the jam nut (10) should be
tightened and the protective cap (1) replaced. If there is a problem of
tampering, lock wire holes have been provided in cap and cover. Wire
the cap to cover and secure with lead seal.
DISASSEMBLY
The CRL Pressure Relief Control does not need to be removed from the
line for disassembly. Make sure that pressure shut down is accompanied
prior to disassembly. If the CRL is removed from the line for disassembly
be sure to use a soft jawed vise to hold body during work.
Refer to Parts List Drawing for Item Numbers.
1. Remove cap (1), loosen jam nut (10) and turn adjusting
screw counterclockwise until spring tension is relieved.
2. Remove the eight screws (4) holding the cover (3) and
powerunit body (6). Hold the cover and powerunit together
and place on a suitable work surface.
See NOTE under REASSEMBLY.
3. Remove the cover (3) from powerunit body (6). The spring
(12) and two spring guides (11).
4. Remove nut (13) from stem (19) and slide off the belleville washer
(14), the upper diaphragm washer (15) and the diaphragm (16).
5. Pull the stem (19) with the disc retainer assembly (21) through the
bottom of powerunit. The lower diaphragm washer (17) will slide off
of stem top.
6. Remove jam nut (23) and disc retainer assembly (21) from stem.
Use soft jawed pliers or vise to hold stem. The polished surface of
stem must not be scored or scratched.
7. The seat (22) need not be removed unless it is damaged. If removal
is necessary use proper size socket wrench and turn counterclock
wise.
Note: Some models have an integral seat in the body (7).
MODEL
INSPECTION
Inspect all parts for damage, or evidence of cross threading. Check
diaphragm and disc retainer assembly for tears, abrasions or other damage. Check all metal parts for damage, corrosion or excessive wear.
REPAIR AND REPLACEMENT
Minor nicks and scratches may be polished out using 400 grit wet or dry
sandpaper fine emery or crocus cloth. Replace all O-rings and any damaged parts.
When ordering replacement parts, be sure to specify parts list item number and all nameplate data.
REASSEMBLY
In general, reassembly is the reverse of disassembly. However, the following steps should be observed:
1. Lubricate the O-Ring (18) with a small amount of a good grade of
waterproof grease, (Dow Corning 44 medium grade or equal).
Use grease sparingly and install O-ring in powerunit body (6).
2. Install stem (19) in powerunit body (6). Use a rotating motion with
minimum pressure to let stem pass through O-ring.
Do Not Cut O-Ring.
3. Install O-ring (5) at top of stem (19). Place lower diaphragm
washer (17) on the stem with the serrated side up. Position
diaphragm (16), upper diaphragm washer (15), with serration down,
and belleville washer (14) with concave side down.
4. Position powerunit body (6) as shown on parts list drawing (top view).
5. Continue reassembly as outlined in disassembly steps 1 through 3.
Note: Item (4) Screw will have a quantity of 8 for the 0-75 and 20-200psi
design and a quantity of 4 for the 100-300psi design. Item (25) Screw is
used on the 100-300psi design only. Install item (25), before item (4) for
preload of item (12) spring.
SYMPTOM PROBABLE CAUSE REMEDY
Fails to open. Controlling pressure
Fails to open with
spring compression
removed.
Leakage from cover
vent hole when controlling pressure is
applied.
Fails to close. No spring compres-
Fails to close with
spring compressed.
too low.
Mechanical obstruction, corrosion, scale
build-up on stem.
Diaphragm Damage Disassembly replace
Loose diaphragm
assembly.
sion.
Mechanical obstruction.
CRL
Back off adjusting
screw until valve
opens.
Disassemble,
locate,and remove
obstruction, scale.
damaged
diaphragm.
Tighten upper
diaphragm washer.
Re-set pressure
adjustment.
Disassemble, locate
and remove
obstruction.
CLA-VAL
P.O. Box 1325 • Newport Beach, CA 92659-0325 • Phone: 949-722-4800 • Fax: 949-548-5441 • E-mail: claval@cla-val.com • Website cla-val.com
©
Copyright Cla-Val 2011 Printed in USA Specifications subject to change without notice.
N-CRL (R-3/2011)
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PARTS LIST
CRL
1/2" & 3/4" PRESSURE RELIEF CONTROL
(Bronze Body with 303SS Trim)
TRUE LOCATION OF
SENSING
CONNECTION
(TYP.)
Ajusting Screw
(3/8" - 16UNF THREAD)
11
13
1/8 - 27 NPT
SENSING
CONNECTION
(TYP.)
18
19
21
INLET
Body with
integral Seat
45º
3.12
DIA.
SIZE SPRING
1/2” 0-75 PSI 7922201E
PART
NUMBER
1/2” 20-105 PSI 7922205F
4
24
1
9
10
3
11
7.44
MAX
12
14
15
4
16
17
5
2
6
OUTLET
20
.71
8
22
23
7
0 TO 75 AND
20 TO 200 PSI
DESIGN
ADJUSTING SCREW
(1/2" 20UNF THREAD)
1
9
10
10.44
3
MAX.
11
12
18
7
.71
100 To 300 psi Design
1/2” 20-200 PSI 7922202C
1/2” 100-300 PSI 8280901D
3/4” 0-75 PSI 7922901K
3/4” 20-105 PSI 7922903F
3/4” 20-200 PSI 7922902H
3/4” 100-300 PSI 8600501E
For 250-600 PSI Contact Factory
CRL
Range PSI
2
0 to 75 8.5 PSI
20 to 105 12.5 PSI
20 to 200 28.0 PSI
100 to 300 18.0 PSI
When ordering parts please specify:
1. All Nameplate Data
2. Item Part Number
3. Item Description
APPROX. INCREASE
CLOCKWISE TURN OF
ADJUSTING SCREW
FOR EACH
Item Description Material Part Number Part Number Part Number Part Number
0-75 20-105 20-200 100-300
1 Cap Plastic 67628J 67628J 67628J 1257601D
2 Nameplate Brass -- -- -- -3 Cover Bronze C2544K C2544K C2544K 44587E
4* Screw Fil. Hd. 10-32 x 1.88 (Qty 8) 303 SS 6757867E 6757867E 6757867E 6757867E
5* O-Ring Rubber 00902H 00902H 00902H 00902H
6 Body, Powerunit Bronze 7920504D 7920504D 7920504D 7920504D
7 1/2” Body Bronze C7928K C7928K C7928K C7928K
3/4” Body Bronze C9083B C9083B C9083B C9083B
8* O-Ring, Seat Rubber 00718H 00718H 00718H 00718H
9 Screw, Adjusting Brass 7188201D 7188201D 7188201D 82811B
10 Nut Hex (Locking) 303 SS 6780106J 6780106J 6780106J 6780606H
11 Guide, Spring 303 SS 71881H 71881H 71881H 1630301J
12 Spring CHR/VAN 71884B 20632101E 71885J 1630201A
13 Nut, Stem Upper Bronze 73034B 73034B 73034B 73034B
14 Washer, Belleville Steel 7055007E 7055007E 7055007E 7055007E
15 Washer, Diaphragm (upper) 303 SS 71891G 71891G 71891G 71891G
16* Diaphragm Rubber C1505B C1505B C1505B C1505B
17 Washer, Diaphragm (lower) 303 SS 45871B 45871B 45871B 45871B
18* O-Ring, Stem Rubber 00746J 00746J 00746J 00746J
19 Stem 303 SS 8982401F 8982401F 8982401F 8982401F
20* O-Ring, Body Rubber 00767E 00767E 00767E 00767E
21* Retainer Assembly, Disc 303 SS C9158B C9158B C9158B C9158B
22 Seat 303Rub 62187A 62187A 62187A 62187A
23 Nut, Hex, Stem, Lower Bronze 6779806G 6779806G 6779806G 6779806G
24 Pipe Plug Bronze 6784701C 6784701C 6784701C 6784701C
FACTORY SET POINT 50 PSI 60 PSI 60 PSI 100 PSI
REPAIR KIT* 9170007A 9170007A 9170007A 9170007A
CLA-VAL
P.O. Box 1325 • Newport Beach, CA 92659-0325 • Phone: 949-722-4800 • Fax: 949-548-5441 • E-mail: claval@cla-val.com • Website cla-val.com
©
Copyright Cla-Val 2011 Printed in USA Specifications subject to change without notice.
PL-CRL (R-8/2011)
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