The Cla-Val Model 81-12/681-12 Check Valve is a hydraulically operated No-Slam Check Valve. This valve opens when the pressure at the inlet exceeds the discharge pressure. A gradual rate of opening prevents sudden opening surges. When a pressure reversal occurs the higher downstream pressure is applied to the cover chamber through the control tube lines, and the valve closes drip tight.

The Cla-Val Model 81-12 does the work of a standard wafer check valve and provides many additional benefits that make it an ideal choice for variable speed drive pump applications where a check valve is needed to prevent return flow.