Proof Load Testing Water Weight Bags Dynamci Drop TestDOOWIN believe in "Professional Cast Quality". We commit to make the highest quality water load test weight bags. DOOWIN water load bags were drop-tested at the TUV National Engineering Laboratory, and gained type test accreditation at the 6:1 safety factor compliance with LEEA Guidance 051. ABS, BV, LR, CCS third party certificate are available upon request too. We are Chinese leading professional manufacturer of underwater air lifting bags, proof load testing water weight bags, lifeboat test water bags, pipeline inflatable buoyancy bags, marine salvage airbags, inflatable fenders and buoys, water tank.