81-01 & 681-01
The Cla-Val Model 81-01 and 681-01 Check Valve are hydraulically operated No-Slam Check Valves. Both valves open 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.