Butterfly Valve

The Bells valve Mod. VRA has been designed to avoid the devastating effects of water hammers in pipeline networks. The purpose is actually to prevent the pressure from rising above a preset value, thanks to its capability of discharging sufficient volume of water directly into the atmosphere.

• Solid and compact design including the reduction cone between the inlet and the sealing seat.
• Negligible inertia of internal mobile parts.
• Perfect sealing seat impervious to cavitation thanks to a special plane gasket.
• Precise and perfect setting without any hysteresis effect thanks to a perfectly balanced and annealed spring.
• Low overpressure values above the preset cracking point thanks to a wide selection of springs.
• Series PN 25 (PN 40 on request).

• Downstream of pumping stations to cushion sudden overpressure as a result of pump start up (in case of one of more pumps in parallel). This is a perfect solution whenever the system is not equipped with soft-Start or other devices to prevent water hammer during starting operations.
• Downstream and upstream of main transmission lines, or pipe segments, not able to endure critical conditions such as sudden and unexpected rise in pressure, and to guarantee reliable system protection.
• Downstream of a PRV as a safety device.
• Upstream of sectioning devices with rapid closing time.
• In general, whenever and wherever pipe bursts are expected.