Rubber Seated Ball Valve


For more than seventy years, the Henry Pratt Company has provided superior quality valves for pump control applications. Our ball valves are designed to meet or exceed AWWA C507 standards. Pratt ball valves have been tested at 300 psi differential for 10,000 cycles per AWWA C-507, Section, proof-of-design requirements and tested bubble-tight at the conclusion of the cycle tests. Ball valves have also been tested to prove their resistance to the effects of cavitation. After several free discharge cycles at 200 psi pressure, a test valve was subjected to a 100 hour continuous cavitation test at 95 psi differential pressure and a valve angle of 25 degrees. Line velocities in excess of 70 feet/second and localized velocities across the seat in excess of 100 feet/second were attained during the tests. At the conclusion of the tests, the valve was bubble-tight at 300 psi.

Henry Pratt introduced the rubber seated ball valve over 30 years ago and this Pratt design has been refined over the years. In addition to replacing most other full port valves, the Pratt ball valve is used extensively in applications where swing check and globetype check valves were formerly used.

The Pratt ball valve has also found extensive applications in high velocity service such as hydroelectric and gravity feed lines where line velocities exceed 50 feet per second. In high-pressure shutoff applications, localized velocities across the seat routinely exceed 100 feet per second. The Pratt ball valve is equally effective as a long lasting shutoff device in potable, raw water and raw sewage applications.

4" through 60"

Body Style:
Flanged ends, three-piece cast construction double seat for bi-directional shutoff.

Pressure Class:
AWWA C507 pressure classes 150 & 300 psi.

Manual: either Pratt MDT (traveling nut type) with nut, handwheel or chainwheel or worm gear operators; Cylinder operators for air, oil or water; Electric motor operators and a complete variety of accessories such as limit switches, control valves, positioner, push button controls, speed control devices and pressure switches.

Automatic pump/check; altitude tank regulation; check service, pressure regulating service.

New Water and Waste Water Industry Standards:
For extended seat life, long-term drop tight closure, lower seating, unseating torque, lower maintenance, simplified operator controls.

The Pratt rubber-seat ball valve fully complies with AWWA standard C507 for tight-closing, shaft-mounted ball valves. It is a proven, rugged, through-port rotary valve that employs modern design techniques. The Pratt ball valve is suited to throttling and on-off service and is adaptable to a variety of control and shut off applications.