Hydraulically Operated Check Valve - 81PM-1 | Cla-Val

Cla-Val 81PM-1 Hydraulically Actuated Check Valve

The Cla-Val 81PM-1 is a hydraulically actuated check valve designed for control circuits in Dry Type Magazine Sprinkler Systems on marine vessels. The 3/8" variant is spring-loaded to close and requires control pressure to open, ensuring positive shutoff in the absence of actuation.

Operating Principle

The 81PM-1 functions as a remotely controlled diaphragm-actuated pilot valve. It is installed in interconnected actuation lines and manages the transition between the open-valve loop and closed-valve loop of the Magazine Sprinkler Valve.

• When control pressure is applied, the 100M-1KR closes and the 81PM-1 opens.
• When control pressure is vented, the 100M-1KR opens and the 81PM-1 closes.
• With control pressure isolated, the system remains in standby and can be actuated via PRPV or manual three-way valves.

Application in AFFF and Sprinkler Systems

The 81PM-1 prevents reverse flow during AFFF (Aqueous Film Forming Foam) deployment. In marine fire suppression, control valves must operate as part of the actuation sequence, not merely as inline components. The valve is suitable for hydraulic actuation piping in both AFFF and dry sprinkler systems.

Technical Selection Points

• Type: Hydraulically actuated check valve
• Reference size: 3/8"
• Operation: Spring-to-close, opens with control pressure
• Application: Hydraulic actuation lines
• System compatibility: Dry Type Magazine Sprinkler / AFFF
• Connection: Union MIL-F1183 (81PM-1)

Maintenance Considerations

Key inspection points include cleanliness of control lines, diaphragm integrity, spring reset function, and leak-tightness under reverse pressure. For AFFF or seawater service, monitor for deposits, crystallization, small bore blockages, and elastomer compatibility with the process media.