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Stainless Steel Double Check Detector Assemblies with Bi-Link Check Valves for High Flow Fire Systems

Series M300Na Double Check Valve Assemblies are specifically designed for high flow fire systems to prevent the backflow of pollutants that are objectionable but not toxic, from entering into the potable water supply. Its compact housing consists of two independently operating bi-link check valves, two shutoff valves, and four test cocks. It features a stainless steel housing and sleeve and is 70% lighter than traditional designs. Series M300Na features the certified lowest pressure loss and is designed for non-health hazard applications and may be installed under continuous pressure service to protect against both backpressure and backsiphonage. This Series is used primarily on fire sprinkler lines when it is necessary to monitor unauthorized use of water. Maximum Working Pressure: 175psi (12.06 bar).


  • Patented bi-link check provides low pressure loss
  • Entire valve body and closure sleeve manufactured from 304 stainless steel
  • Extremely compact design is significantly lighter than traditional designs
  • Can be installed under continuous pressure service to protect against backpressure and backsiphonage

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Select options below to identify the UPC, Order Code, and Repair Kit for a specific M300NA

Approval Information

For approval information, please refer to the products specification sheet. For any other information on product certification and documentation information, please visit our certification partner websites: