"Scott Bemis" wrote in message
om...

At www.underwaterfloation.com/drybags.htm, there are Prolift over
pressure valves used in liftbags. Prolift Over Pressure Valves are
available in 2 styles. The two piece black screw type is used on our
smaller liftbags and requires no special tooling for installation.

Scott, FWIW the black valve looks like a standard BCD OPV valve. These are
also used in small (50kg) personal lift bags used by recreational divers.

Cheers
David M