The Plast-O-Matic Valves series BSR/BSRM balanced air-operated shutoff valves provide positive, bubble tight, fail-safe shutoff featuring normally-closed operation.
In this design, the surface area of the pressurized seat and seals is equal to the area of the main orifice. The liquid pressure has no impact on shaft movement, and there is no need for pressure differential. The inlet and outlet pressures can be equal up to 150 PSI.
Series BSR is a robust, globe style valve with no wetted metals and features a heavy-duty fail safe spring. Air opens the valve, spring automatically closes when air pressure is shut off.
These features make this valve a favorite in any application where the valve absolutely, positively must close bubble-tight under virtually any circumstances.
Image credit: Plast-O-Matic Valves, Inc.