DOOWIN single point buoyancy unit is one kind enclosed pipeline buoyancy bag. It only has one single lifting point. So it is very effective for the steel or HDPE pipelines laying work at or near the surface. Moreover it also can work at large angle, like the parachute type air lift bags.
Vertical single point mono buoyancy units are made of heavy duty PVC coating fabric material in compliance with IMCA D016. Each enclosed vertical single point buoyancy unit is fitted with pressurer relief valves, and filling /discharge ball valves. One internal strop is used connect the top lifting point with the bottom to reinforce the lifting capacity.
DOOWIN make single point buoyancy bags with capacity less than 5 ton. For the bigger capacity, you can choose parachute lift bags.