The PRV45 pressure reducing valve by Valfonta is a high-sensitivity device designed for precise fluid control, especially suitable for gases and steam at reduced pressures. Unlike piston models, this design incorporates a large-diameter diaphragm actuator, allowing regulation of very low outlet pressures (in the millibar range) with high stability.
Manufactured entirely in AISI 316L Stainless Steel, it is a robust and clean solution, ideal for chemical, pharmaceutical, and food industry applications. Suitable for working with steam (up to 180°C), compressed air, nitrogen, and other inert gases, it offers tight shut-off and a quick response to consumption variations.
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Size Range: Available in 1/2" (DN15), 3/4" (DN20) and 1" (DN25).
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Maximum inlet pressure: Supports up to 25 barg.
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Regulation range (Low pressure): Its main strength is fine regulation capability. Depending on the actuator installed, it covers ranges from 10 mbar up to 8 barg.
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Materials: "Full Inox" construction with body, internals, and actuator in AISI 316L Stainless Steel.
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Temperature limits:
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Liquids and gases: -20°C to +80°C.
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Steam: Up to 180°C (with suitable configuration).
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Connections: Threaded BSP / NPT and flanged DIN / ANSI. Clamp option on request.
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Maintenance: Designed to be a low maintenance device.
The PRV45 operates by direct action compensated by diaphragm. The inlet pressure enters the valve body, but it is the interaction between the spring and the large surface of the diaphragm that dictates the regulation:
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Sensitivity: With a large-diameter diaphragm, the valve is able to detect and react to minimal changes in outlet pressure, allowing operation in millibar ranges.
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Regulation: By compressing the upper spring, the closure assembly is pushed to open the valve.
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Stability: The outlet pressure acts under the diaphragm opposing the spring. When equilibrium is reached, the valve maintains constant pressure. If consumption stops, the valve closes tightly to prevent downstream pressure increase.
Due to the size of its actuator and its sensitivity, installation requires special attention:
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Mounting position:
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Recommended: On horizontal piping with the actuator vertically upwards (standard position for liquids and gases).
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Not allowed: Unlike the PRV30/44, this model MUST NOT be installed inverted (with the actuator down), as it would not function properly.
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Filtration: It is mandatory to install a strainer filter before the valve to protect the seat and diaphragm from particles.
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Pressure take-off: Supplied with internal pressure take-off, so external control piping is generally not required.
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Adjustment: It is made by turning the upper screw with a fixed spanner or Allen key. Turn counterclockwise (decompress) to reduce pressure and clockwise (compress) to increase it. Note: Verify exact direction at start-up according to the spring configuration.
