Safety Valves series ALPER atmospheric valves | Valfonta

Valfonta ALPER Atmospheric Pressure/Vacuum Relief Valves

Valfonta ALPER atmospheric valves are designed for the protection of storage tanks and closed vessels against overpressure and vacuum conditions. These valves feature a modulating opening characteristic, utilizing adjustable springs for pressure, vacuum, or combined pressure/vacuum settings. Outlet is 90° angled and protected by a stainless steel mesh to prevent ingress of particulates.

Technical Specifications

• Sizes: 1/2" to 4"
• Set Pressure (Positive): +0.080 to +8 bar
• Vacuum Setting: -0.050 to -0.650 bar
• Max Temperature: up to 280°C (stainless steel construction)
• Inlet Connection: Male BSP or DIN flange
• Outlet Connection: Female BSP; flanged outlet available on request
• Materials: RG5 bronze or AISI 316L / CF-8M stainless steel
• Options: NPT threads, ANSI flanges, AISI 302/316 stainless steel spring

Variants

Types 334 / 335 / 350 / 351 are configured for vacuum-only operation. Types 336 / 337 / 352 / 353 support both pressure and vacuum settings. 334–337 are stainless steel; 350–353 are bronze. Models 335 / 337 / 351 / 353 include DIN flanged inlets.

Applications

Suitable for closed tanks, storage vessels, liquid circuits, compressed air, inert gases, and low-pressure steam. Valve selection should consider set pressure, vacuum, air flow, temperature, process media, and connection type. Compatible with neutral and non-corrosive media; consult for aggressive media compatibility.

Maintenance

Maintain outlet mesh free of deposits. Accumulation or condensate on the seat may alter setpoint or cause leakage. For vacuum service, ensure air inlet cleanliness and chemical compatibility of wetted parts.