LEFF® Function - Low-Emission Flip-Flop

GEA is constantly developing new solutions to improve customers’ process efficiency, reduce the consumption of valuable resources, and contribute to more sustainable production.The LEFF® feature, which is integrated into GEA T.VIS® A-15 control tops, has been awarded the GEA Add Better label* for its positive impact on reducing water consumption.

In conventional cleaning, mixproof valves run a time-based seat lift cycle to clean the valve seats and the leakage chamber. LEFF® is a smarter and more efficient alternative—the valve opens in a pulsating sequence controlled by the valve’s position using position sensing instead of fixed time intervals. This increases the flushing intensity and effectively shortens flushing times for water and chemicals. This has been shown to reduce water and cleaning agent consumption by up to 92% during seat cleaning.

*The add Better label relates to the LEFF® function integrated in GEA T.VIS control top, released in 2003, which saves 92% of water in comparison to conventional valve seat cleaning.

• LEFF® is integrated as a standard feature in the T.VIS® A-15 control head—the best choice for mix-proof double-seat valves
• No complicated programming is required in the PLC
• No additional system technology is required
• Automatic Monitoring of the Seat Lift Function
• Significant cost reductions: up to 92 % savings in water and CIP media

For double-seat valves, standard feedback units are simply used, without the need for any special components. The simple configuration with two push buttons on the T.VIS® cover allows the LEFF® function to be activated separately at any time during installation for the valve cone, the double cone, or even both.

By using pulsed control of the valve cones during the seat lift, the consumption of cleaning agents and the amount of fluid discharged into the sewer can be significantly reduced compared to a conventional seat lift function, which substantially lowers operating costs.