Power Hy-Check Valve - 181PM-EP | Cla-Val

Cla-Val 181PM-EP Power Hy-Check Valve for AFFF Concentrate

The Cla-Val 181PM-EP is a hydraulically operated check valve of the Power Hy-Check type, designed for AFFF concentrate lines in marine fire-fighting systems. Its function is to prevent reverse flow within the foam concentrate circuit, where backflow may affect dosing, isolation, or downstream equipment operation. The product documentation specifies construction in accordance with MIL-F20042.

Technical Classification

In the Cla-Val marine catalog, the 181PM-EP is listed as a Power Hy-Check Valve (AFFF Concentrate). The EP suffix indicates ethylene propylene elastomers, which must be verified for chemical compatibility with the specific AFFF concentrate used in the project.

Dimensions and Connections

For the 181PM-EP, the table lists application in AFFF Foam Systems, flanged connections, and compliance with MIL-F-20042 Class 250. Available sizes for this series include 1/2", 2", 2 1/2", 3", 4", 5", and 6".

Differences from Related Versions

• 181M-EP: Hy-Check for sea water.
• 181PM-EP: Power Hy-Check for AFFF concentrate.
• 181M-2: Hy-Check for AFFF foam system in different configuration/size.

Distinction is critical, as seawater, foam mixture, and AFFF concentrate each require different service considerations.

Selection Criteria

During technical submittal, confirm the following:

• AFFF concentrate type and EP elastomer compatibility
• operating pressure and flange class MIL-F-20042 Class 250
• flow direction and available control pressure
• requirement for flushing after testing or activation
• access for inspection of diaphragm, seat, and pilot lines

Maintenance

For AFFF concentrate service, inspect for foam residue, crystallization, blockages in small internal passages, diaphragm condition, and sealing under backpressure.