Gestra BB2 Dual-Plate Check Valve

Description
Dual-plate check valves prevent backflow in horizontal and
vertical pipes. They are of the wafer pattern designed to be
sandwiched between flanges.
For installation in horizontal and vertical pipes with upward
flow the valves can be fitted with springs. For installation in
horizontal and vertical pipes with downward flow the valves
must be fitted with special springs.
Dual-plate check valves are to be used for liquids, gases
and vapours, provided that the specifications of the PED are
taken into account.