Cla-Val Models 250-01 and 605-01 Differential Pressure Relief Valves are hydraulically operated, pilot-controlled, modulating valves. They are designed to maintain a constant pressure differential between any two pressure points in a system where the closing of the valve directly causes the differential pressure to increase. The valves tend to open on an increase in differential pressure and close on a decrease in differential pressure. Typical applications include differential pressure control in centrifugal pumping systems and chilled water circulating loop systems.
Hydraulic Pressure Control Valves - 250-01 & 605-01 Differential Pressure Relief Valve | Cla-Val
Cla-Val 250-01 / 605-01
Pilot-operated, modulating differential pressure relief valve. Maintains a constant differential pressure between two network points. The valve opens as differential pressure rises above setpoint and closes as it drops below.
Applications
- Centrifugal pump circuits
- Chilled water networks / closed-loop HVAC systems
- Pump by-pass for ΔP control
- Equipment protection against excessive differential pressure
- Industrial water systems with variable demand
Technical Operation
The main valve is controlled by a differential pressure pilot. Pressure from two measurement points is routed to the pilot circuit. When ΔP exceeds the setpoint, the valve modulates open to relieve flow, typically to a by-pass or return line. The design allows stable control in dynamic system conditions.
Construction
- Connection: Flanged
- Standard: ANSI
- Pressure classes: 150 lbs, 300 lbs
- Body materials: Bronze, ASTM A216 WCB, ductile iron
Selection Criteria
Sizing should be based on by-pass flow, available pressure, required ΔP setpoint, acceptable pressure drop, and cavitation risk. In pump systems, the location of pressure sensing (upstream/downstream of equipment) directly affects control stability.
FAQ
Is this a simple relief valve?
No. It controls differential pressure between two points, not just inlet pressure.
Suitable media?
Primarily water and fluids compatible with construction materials.
Is electrical power required?
Not for basic hydraulic operation.
Description
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