Pressure Excess Valves type PRV55 | Valfonta

Valfonta PRV55 – Low Set Point Pressure Relief Valve

The PRV55 is a self-acting, balanced inlet pressure maintenance valve. It operates on a direct acting principle: when the upstream pressure exceeds the set value, the piston/seal assembly opens proportionally, releasing flow to the downstream line or bypass.

Technical Specifications

• DN15–DN25 / ½”–1”
• Connections: BSP, NPT, flanges EN or ANSI, clamp upon request
• Body and trim material: AISI 316L, RG10 bronze available on request
• PN25
• Kvs: 2 / 2.5 / 3.5 m³/h, special Kv available
• Operating temperature: -10 to 180°C
• Adjustment ranges: 10–200 mbar, 100–1000 mbar, 0.5–2 bar, 1–4 bar, 3–8 bar

Operating Pressure

The commercial page states a maximum inlet pressure of 8 barg, while the PRV55-16B technical sheet specifies 16 bar. Verification of version, nameplate, and required set point is necessary for replacement or new supply.

Fluids and Applications

Suitable for Group 1 and Group 2 liquids and gases, steam, compressed air, nitrogen, water, fuel-oil, and inert gases. Used in laboratory installations, sanitary plants, sprinklers, heat exchangers, steam generation lines, washers, and auxiliary process circuits.

Installation

The PRV55 is installed in horizontal piping, with flow according to the body arrow. An upstream filter, pipe cleaning, and support from the piping, not the valve or actuator, are recommended. For steam and liquids above 125°C, an external control line and condensate pot are required to protect the diaphragm.

FAQ

How does it differ from PRV53/PRV54?
The PRV55 covers lower set points, down to mbar, with a larger activation diaphragm.

Does it require external energy?
No. Adjustment is mechanically achieved via upstream pressure and spring.