Hydraulic Pressure Control Valves - 750-01 Pressure Relief, Sustaining & Back Pressure Valve | Cla-Val | Philippopoulos s.a.
Hydraulic Pressure Control Valves - 750-01 Pressure Relief, Sustaining & Back Pressure Valve | Cla-Val | Philippopoulos s.a.

Hydraulic Pressure Control Valves - 750-01 Pressure Relief, Sustaining & Back Pressure Valve | Cla-Val

Cla-Val 750-01

The Cla-Val 750-01 is a pilot-operated, modulating hydraulic relief, backpressure, and pressure sustaining valve for water distribution networks. The valve maintains upstream pressure by modulating flow through a pilot control circuit, without requiring external power.

Operation

When inlet (upstream) pressure exceeds the set point, the valve opens proportionally to relieve excess flow. As upstream pressure drops below the set point, the valve closes gradually, maintaining the required upstream pressure. The pilot system ensures stable modulation and prevents pressure surges.

Applications

  • Pump by-pass circuits
  • Backpressure regulation in process lines
  • Unloading centrifugal pumps
  • Pipeline overpressure protection
  • Maintaining pressure in upstream zones

Selection Criteria

  • Required relief or by-pass flow rate
  • Upstream pressure set point
  • Available downstream backpressure
  • Continuous or intermittent operation
  • Cavitation risk at high ΔP
  • Material compatibility with water or process fluids

Difference from PRV

Pressure Reducing Valves (PRVs) control downstream pressure. The 750-01 controls upstream pressure, relieving or restricting flow as needed to maintain setpoint upstream.

Technical Notes

  • Suitable for potable water, process water, and compatible fluids
  • Available in ductile iron, bronze, or stainless steel bodies
  • Sealing options: EPDM, NBR, FKM
  • Pressure classes: PN10–PN25, ANSI 150/300
  • Temperature range: typically 0–80°C (media dependent)
  • Optional position indicators and limit switches
  • Meets relevant international standards (e.g., EN 1074, NSF/ANSI 61)

FAQ

Does it require electrical power?
No. Regulation is fully hydraulic via the pilot circuit.

Is it a safety valve?
No. The 750-01 is a pressure control valve and does not replace certified safety relief valves per PED or ASME standards.

Datasheet and documents

Description

The Cla-Val Model 750-01 Pressure Relief, Sustaining and Back Pressure Valve is a hydraulically operated pilot actuated automatic control valve. The main valve consists of only two parts, a stainless steel body and an elastomeric liner or control element.

The main valve opens when inlet pressure begins to exceed a preset pressure and will allow enough flow to maintain that inlet pressure. In pressure sustaining service, Model 750-01 will conserve pressure in an upper system during periods of high demand in a system below. In pressure relief service, this valve will modulate to exhaust line pressure to keep it below a set point maximum. On a pump bypass system, the valve will allow flow back to the pump suction when pump discharge pressure exceeds the set point.

Cla-Val Model 750-01 will control from no flow to full open flow without any chattering or slamming under low flow conditions. For this reason, on by-pass, relief, and pressure sustaining service, there is never a region of control instability.