Compact, Durable Piston Valves with Optimised Flow Rates

With the 85700 series of piston valves currently being introduced at the Hanover Fair 2003, IMI Norgren Buschjost is entering new territory, even, or better especially as the completely new design is based on the well-known and trend-setting Click-on® technology.

Buschjost has developed a solenoid mounting system powerful enough to exert the high forces required by a piston valve with forced lifting. The dry solenoid system is easily fitted and replaced without tools. The captive stainless steel clip engages in the solenoid to hold it securely on the body in all positions. The solenoid can be stored separately and quickly clicked onto the body for the particular application. The system covers all standard voltages and an ATEX approved EEX me explosion protected model is available.

The series offers valves with connections ranging from G 1/4 to G2. All of the standard models are designed for pressures ranges from 0 to 25 bar, and special models are capable for 0 up to 40 bar.

The most immediate striking feature of the newly developed body of the valve is the piston guide. It holds the piston in position as far outside the flow passage as possible while the valve is open. As well as significantly improving flow rates this design principle protects the piston bearing against deposits. In practice this means higher service life expectations and increased reliability.

The piston bushings are manufactured from stainless steel with a specially treated surface. Buschjost has paid special attention to the arrangement of the seals and the quality of the piston bearing surfaces.

Even completely uncontamined fluids can cause a gradual build-up of deposits, eg limescale in water and steam pipes.

The standard version of the 85700 series of valves can be used for neutral fluids at up to 90 degrees, the EPDM or FPM seals fitted to the special models extend the temperature range to 200°C. Options include a manual override and an electric position indicator.