Find test pumps at Grainger to help find leaks in water lines, boilers, small water tanks, sprinkler systems and more. A hydrostatic test pump can test vessels and water pipes for structural flaws and leaks by pressurizing them with water. Find twin piston, triplex plunger and triple diaphragm positive displacement pumps. Two- and four-outlet positive displacement fire hose testers can test single or multiple water lines to help prevent using damaged lines. Get reliable test pumps at Grainger.