SLT10050 Dixon Brass Sprinkler Line Tester - 1" Female NPT Inlet x 1" Male NPSH OutletApplications: For installing the last sprinkler head on system branch lines, controls water flow for flushing or testing of the system. When the wet pipe sprinkler system operates, the water flow in the pipes is at a relatively low velocity. Friction loss increases with the age of the sprinkler piping, up to 100 percent after 15 years. The accumulation of sediment and foreign objects in sprinkler systems can be prevented by flushing the supply mains