The Subsalve PDV Plunger Dump Valve for Commercial Lift Bags provides air control with a push-button knob at the top of the bag and a lanyard at the bottom of the bag.
Brand Subsalve Video No
How do I dump the air out of my lift bag?
There is a black Plunger Dump Valve on the top of the lift bag that releases the air from the lift bag. You can control the ascent of the lift bag by pulling the lanyard that is connected to this valve.
If you are using an Enclosed Floatation bag or Salvage Pontoon, you can find the Plunger Dump Valve on the side or corners of the lift bag.