These requirements cover check valves of 1-inch nominal size and larger@ used in piping systems supplying water for fire protection service. The check valves covered by these requirements are intended for installation and use in accordance with the Standards for: Low- Medium- and High- Expansion Foam and Combined Agent Systems@ NFPA 11; Installation of Sprinkler Systems@ NFPA 13; Installation of Standpipe and Hose Systems@ NFPA 14; Water Spray Fixed Systems for Fire Protection@ NFPA 15; Deluge Foam-Water Sprinkler and Spray Systems@ NFPA 16; Installation of Centrifugal Fire Pumps@ NFPA 20; Water Tanks for Private Fire Protection@ NFPA 22; Installation of Private Fire Service Mains and Their Appurtenances@ NFPA 24; Water Mist Fire Protection Systems@ NFPA 750; and Installation of Sprinkler Systems in Residential Occupancies up to and Including Four Stories in Height@ NFPA 13R.