The function describes modulation of the valve disc during the lifting procedure which is monitored by the path measuring system and the electronics of the T.VIS® A-15, and works independently from the process run times and product pressures.
In double-seat valves it only uses the feedback units provided as standard, without needing any special components. The straightforward configuration using two push buttons on the T.VIS® hood allows a separate LEFF® function activation during set-up for the valve or double disc at any time. To allow the LEFF® function to be used with the double disc, it is necessary to have the optional external proximity switch.
Modulation of the valve disc during lifting makes it possible to significantly reduce cleaning agent consumption and/or discharge into the drains compared to the conventional lifting method, thereby drastically reducing operating costs.