Having selected the basic frame type it is then necessary to specify one of the Following alternatives:-
A:- Is the gate to take – On-seating head ?
Off seating head ?
On and off –seating head ?
On – seating head – Pressure forcing the door onto the frame.
Off- seating head - Pressure forcing the door away from the frame.
Modulating penstocks for flow control purposes where gates may be frequently repositioned and utilise only a portion of the full stroke, require special consideration and may necessitate
Larger than standard stems
Slow operating speeder
Continuously rated motors on actuators
Special heat absorbing drive shelves