The new ‘pulse seat clean’ feature does for drain valves what the burst seat clean did in 2019 for mixproof valves. While ‘burst seat clean’ reduces CIP liquid for mixproof valves by up to 90%, the ‘pulse seat clea’n cuts drain valve CIP liquid consumption by up to 95%.
This standard automated valve-position feature is triggered by a rising programmable logic controller (PLC) signal and controlled by the Alfa Laval ThinkTop V50 and V70 sensing and control units.
Short bursts, or pulses, drive the valve cleaning process, activating the valve when shear forces peak. Each position-based pulse takes less than a second, preventing pressure shocks in the system. The pulse creates high turbulent flow as the liquid passes through the narrow gap between the valve house and valve seat, effectively removing all residuals, says Alfa Laval.
The pulse seat clean makes control and validation of valve cleaning cycles easy. The valve position is not controlled by the PLC timer but by the Alfa Laval ThinkTop. Besides reducing the volume of CIP liquid used, programming the sensor to open and close the seat quickly ensures faster, more rigorous cleaning and hygiene than timer-controlled cleaning, according to Alfa Laval. The ThinkTop also verifies that valve cleaning has been completed.
Intended for use with single-seat valves or butterfly valves used as drain valves, pulse seat clean is a standard feature of ThinkTop V50 and V70 sensing and control units with one solenoid valve. Regardless of actuator mode, the drain valve may be configured as a normally open or normally closed shutoff or changeover valve.
“The ThinkTop pulse seat clean brings unheard-of savings in CIP liquid to process plant owners and operators compared to conventional PLC timer-controlled seat cleaning,” says René Stietz, product portfolio manager, valves and automation, Alfa Laval.