Hydraulic Pressure Control Valves - 550-01 & 6550-01 Pressure Relief & Sustaining Valve | Cla-Val

Cla-Val 550-01 / 6550-01

Hydraulic pressure relief and sustaining valve for water distribution networks. Designed for relief, sustaining, back pressure, and unloading functions. Pilot-operated and modulating, with upstream pressure control. Suitable for potable and industrial water. Compatible with standard water treatment chemicals. Typical pressure classes: PN10–PN25. Temperature range: 0–80°C, depending on elastomer selection.

Operation

When inlet pressure exceeds the set point, the pilot valve opens, causing the main valve to discharge flow to bypass, tank, or return line. As pressure drops below set point, the valve closes in a controlled manner. Modulating action maintains upstream pressure within defined limits.

Applications

• Pump station overpressure protection
• Minimum upstream pressure maintenance
• Back pressure control in industrial water systems
• Unloading of centrifugal pumps
• Bypass between discharge and return lines

Variants

• 550-01: Full port, for higher available flow area. Suitable for high flow relief applications.
• 6550-01: Reduced port, for lower flow rates and improved modulation in oversized pipelines.

Selection Criteria

Selection is based on required relief flow, set point, upstream pressure, back pressure, allowable flow velocity, and cavitation risk. For continuous bypass operation, verify pump thermal loading and ensure sufficient return flow. Consult relevant standards (e.g., EN 1074, ISO 5208) for sizing and installation.

FAQ

Is this the same as a PRV?
No. PRVs control downstream pressure. The 550-01 / 6550-01 maintains or relieves upstream pressure.

Is electrical power required?
No. Standard operation is fully hydraulic via pilot circuit. Electric actuation available as an option.