They are used for two main tasks:
- By restricting the valve opening a change in flow conditions occurs where both flow velocity through the valve and pressure across the valve increases, resulting in conditions that create cavitation
- To be able to control the pressure and flow precisely and finely, the valve's flow control characteristics must be as linear as possible over the whole opening range.
Thanks to their well thought out design, Pratt Series 300 Plunger Valves fulfill these requirements to the greatest possible degree and are therefore the ideal valve for numerous control tasks. Butterfly and gate valves, due to their design as isolation or, open/closed valves, are not suitable for continuous use as a variable flow control valve.
Pratt Series 300 Plunger Valves are especially suitable for drinking water, raw water and air. Typical applications include:
- Pump start-up and control valve
- Reservoir inlet
- Control device in the bottom outlet valve of dams (with or without venting)
- Control device in the inlet and bypass of turbines
- Safety device in the bypass outlet of turbines for quick opening
- Surge anticipating device in pumping or pressurized systems.