Cla-Val 250-01/605-01 - Manual (Page 5)

On a chilled water circulating loop system the 250-01/605-01
Differential Pressure Relief Valve is installed between loop supply
and return lines to maintain a constant differential
across the loop. The loop differential pressure remains
constant regardless of the loop demand change there-
by increasing cooling system efficiency.
• Accurate Differential Pressure Control
• Controls Maximum Flow Through Pumps
• Circulating Loop Flow Control
• Completely Automatic Operation
The Cla-Val Model 250-01/605-01 Differential Pressure Relief Valve is
a hydraulically operated, pilot-controlled, modulating valve. It is
designed to maintain a constant pressure differential between any two
pressure points in a system where the closing of the valve directly caus-
es the differential pressure to increase. The valve tends to open on an
increase in differential pressure and close on a decrease in differential
pressure.
In operation, the valve is actuated by line pressure through a pilot con-
trol system sensing from two points across which a differential is to be
maintained. Operation is completely automatic and pressure settings
may be easily changed.
Schematic Diagram
Item Description
1 Hytrol (Main Valve)
2 X42N-2 Strainer & Needle Valve
3 CDB-7 Differential Control
Optional Features
Item Description
B CK2 (Isolation Valve)
D Check Valves with Isolation Valve
F Remote Pilot Sensing (H.P.)
S CV Speed Control (Opening)
The Model 250-01/605-01 Differential Pressure Relief Valve main-
tains a constant differential across centrifugal pump regardless of
variable upstream pressures or downstream demand.
By maintaining a constant differential pressure across a centrifugal
pump operating at a known capacity, the maximum flow rate is controlled.
Supply to
Cirulating
Loop
Chilled Water
Supply
Return
From Loop
CLA-VAL
250-01/605-01
Differential Pressure
Relief Valve
VARIABLE
PRESSURE
MAIN
PUMP
CLA-VAL 250-01/605-01
DIFFERENTIAL RELIEF
& CHECK VALVE
VARIABLE
DEMAND
PUMP SUCTION LOW PRESSURE SENSING
CONNECTED TO DIFFERENTIAL CONTROL
B1
D1
2
B1
S
D2
D3
B2
3
F
REMOTE SENSING
L.P.
INLET OUTLET
1
H.P.
Differential Pressure Relief Valve
Typical Applications
250-01
MODEL
(Full Internal Port)
605-01
(Reduced Internal Port)