GESTRA Flowserve RK 41 Instructions De Montage Et De Mise En Service page 13

Description
Non-return valve RK with spiral centering ring or self-centering body.
Installation in any position. Exception: Valves without spring can only be
installed in vertical lines with upward flow.
1
Non-return valve with spiral centering ring
2
Non-return valve with self-centering body
3
Position of guide ribs (horizontal installation)