Cla-Val CRD40 User Manual

INSTALLATION / OPERATION / MAINTENANCE

Description

The CRD40 Pressure Reducing Control automatically reduces a
higher inlet pressure to a lower outlet pressure. It is a direct act­ing, spring loaded, diaphragm type control that operates hydrauli­cally. It is used as a pilot control with Cla-Val automatic control
valves to hold a constant downstream pressure. Cla-Val Model
CRD40 maximum inlet pressure rating: 400 psi

Installation and Adjustment

Before installing the CRD40 Pressure Reducing Control, flush out
line to remove loose dirt and scale which might damage seal ring
and seat. Install control in-line with arrow on valve body pointing
in direction of flow. The CRD40 may be installed in any position.

The standard adjustment range is 15 to 150 psi with a factory set­ting of 50 psi. To readjust outlet pressure, loosen lock nut and
turn adjustment bolt clockwise (into bell housing) to raise outlet
pressure. To lower outlet pressure setting turn adjustment bolt
counterclockwise (out of bell housing).

Caution: A pressure gauge must be used downstream to verify
correct pressure setting. Do not bottom out adjustment bolt on
bell housing.

MODEL

CRD40

Pressure Reducing Control

Reassembly

1. If possible, flush any debris out of valve body by allowing some
water flow while CRD40 is apart.

2. Replace old cartridge assembly with new cartridge assembly.
Carefully push new cartridge assembly into body making sure O­rings seal tight against both cartridge and body. A small amount
of waterproof grease on O-rings may help cartridge assembly slip
into place.

3. Replace friction ring, spring, spring disc and bell housing with
adjustment bolt in place in order shown on drawing. Friction ring
must be installed as shown in diagram to avoid damage.

4. Turn adjustment bolt into bell housing to original measured set­ting.

5. After remaining components of control valve pilot system and
main valve are serviced, recheck pressure setting of CRD40 with
flow through the valve. To readjust outlet pressure, loosen outer
lock nut and turn adjustment bolt clockwise (into bell housing) to
raise outlet pressure setting, turn adjustment bolt counterclock­wise (out of bell housing) to lower outlet pressure setting.

Notice: To ensure proper performance and maximum service life
for the CRD40, it is suggested that a program of regular inspec­tion, testing, maintenance and cleaning be utilized. Annual
inspection and maintenance is recommended.

Disassembly

1. Before starting disassembly remove line pressure from control.

2. Measure distance adjustment bolt protrudes from bell housing.
Loosen lock nut on adjustment bolt and turn adjustment bolt out
of bell housing only to remove spring tension. DO NOT REMOVE

ADJUSTMENT BOLT, SPACER OR lock nut FROM BELL
HOUSING.

3. Unscrew bell housing counterclockwise and remove spring,
spring disc and friction ring.

4. Remove cartridge assembly from valve body by gripping
retaining bolt with pliers and pulling outward away from valve
body.

Troubleshooting

Symptom

Fails to close
when outlet
pressure rises

Fails to open
when outlet
pressure lowers

1

⁄2” & 3⁄4” CRD40 Repair Kit Part Number 20348406K

Probable Cause

Foreign matter on
seating face of seal
O-ring

Cartridge assembly
damaged

Cut or worn stem
O-ring or worn
O-ring groove

Spring compressed
solid

Cartridge assembly
damaged

No spring
compression

Damaged spring

Remedy

Disassemble and
remove

Disassemble and
replace

Replace cartridge
assembly

Loosen
adjustment bolt

Disassemble
and replace

Tighten adjustment
bolt

Disassemble and
replace

ADJUSTMENT
BOLT

1 /2” CRD-40 Pressure Reducing Control Valve

LOCKNUT

SPACER

BELL
HOUSING

*

SPRING DISC

RETAINING
BOLT*

PRESSURE LIMIT
SPACER

FRICTION
RING
Detial

*FRICTION RING

*SPRING

*CARTRIDGE
ASSEMBLY

*UPPER O-RING

LOWER O-RING*

Sizes:

1

⁄2” - 3⁄4”

*Indicates Parts Supplied in CRD40 Repair Kit P/N 20348406K

FLOW CHARACTERISTICS

MODEL CRD40 1/2" & 3/4" (STANDARD & METRIC)

FLOW RATES (I/s)

20

1/2" (15mm)

3/4" (20mm)

15

10

5

0

PRESSURE LOSS (PSIG)

01020

FLOW RATES (GPM)

1.30.6 1.9 2.5

*SEAL RING

*BODY

30 40

138

104

69

35

PRESSURE LOSS (kpa)

CLA-VAL

P.O. Box 1325 • Newport Beach, CA 92659-0325 • Phone: [phone] • Fax: [phone] • E-mail: [e-mail] • Website cla-val.com

©

Copyright Cla-Val 2009 Printed in USA Specifications subject to change without notice.

N-CRD40 (R-8/09)