The ALPER safety valve from Valfonta is a protection device against overpressure with total and instant opening (A.I.T.). It is designed to automatically detect excess pressure in boilers, tanks and pipes, releasing the surplus fluid to protect the integrity of the installation.
Certified in accordance with PED 97/23/EC, it is a reliable and robust solution that does not require auxiliary power. When normal operating pressure is restored, the valve closes automatically, ensuring tightness. All units are bench-tested with compressed air and delivered pre-set to the client's requested pressure. Its design includes a 1/4" drain hole in the body to facilitate condensate drainage and prevent internal corrosion.
- Opening Type: Instant Total Opening (A.I.T.) with 90° guided discharge.
- Compatible Fluids: Steam, compressed air, inert gases and liquids.
- Maximum Design Pressure:
- Metal Seal: PN25.
- Teflon (PTFE) Seal: PN16.
- Temperature Limits:
- Stainless Steel Version: Up to 280°C.
- Bronze Version: Up to 240°C.
- Materials:
- Body and Foot: Available in RG5 Bronze or AISI 316L Stainless Steel.
- Disc: AISI 316L Stainless Steel, RG5 Bronze, or Teflon (PTFE).
- Connections:
- Inlet: BSP Male Gas Thread or DIN Flanges (ANSI upon request).
- Outlet: BSP Female Gas Thread.
The valve remains closed by the force of a calibrated spring. When the system's internal pressure exceeds the spring force (set pressure), the disc instantly lifts (instant opening), allowing rapid evacuation of the fluid through the guided discharge outlet. Once pressure drops below the set value, the spring pushes the disc back against the seat, closing the valve tightly.
- Special Options: On request, can be supplied with AISI 302/316 stainless steel springs, soft seals in Viton, NBR or EPDM, and NPT connections.
- Installation: Must be installed in a vertical position, with the lever (if equipped) oriented to allow manual operation for periodic testing.
- Drainage: It is recommended to connect the lower drain hole to prevent liquid accumulation in the discharge chamber.









