WFN model Upright and Pendent Foam-Water Sprinklers are air-aspirating foam discharge outlets designed for use in foam-water deluge systems. They are designed for flammable liquid risks where it is necessary to apply foam from overhead sprinklers (either upright or pendent) and where a follow-up with plain water in a standard spray sprinkler pattern is necessary as in the case of NFPA 16, "Standard for the Installation of Foam-Water Sprinkler and Foam-Water Spray Systems". It is recommended that the end user be consulted with respect to the suitability of the materials of construction such as brass and stainless steel options which are available for any corrosive environment. WFN model Foam-Water Sprinklers are designed with a unique venture style body. While the foam solution flows through the inlet of the body, air is drawn into the body through the openings adjacent to the wrenching area. The foam solution and air mix is then agitated to create air-aspirated foam. WFN model Foam-Water Sprinklers are designed to discharge foam in a predetermined discharge pattern, as well as to discharge water similar to standard spray sprinklers. To meet the requirements of NFPA 16, foam-water sprinklers must be able to sufficiently distribute water after depletion of the foam concentrate. The connection to the fire protection network is threaded DN 15-1/2" and flow rates are factory calibrated and tested according to client's request up to Metric K factor 591/min * bar ½.