Welcome You Visit DOOWIN

The Most Professional Manufacturer of Test Weight Water Bags and Underwater Lift Bags.
DooFlex is our trademark for flexible engineering products made of PVC/TPU material.
To Be Your Best Partner – Your safety is our mission!

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DOOWIN is Chinese leading professional manufacturer underwater lift bags, marine salvage bags and crane test water weight bags in complying with international standard IMCA D016 and LEEA 051. We also produce various inflatable pipeline buoyancy units, water or fuel storage bladder tanks, inflatable boat fenders and buoys, inflatable pipe plugs, and other flexible products made of PVC/TPU coating fabric.
Our underwater lift bags include open bottom parachute type, totally enclosed type, pillow type, and other customized shapes. These air lifting bags can be used for diving work, marine salvage and refloating operation, pipeline layering buoyancy support. Our water weights bags can be used for the proof load testing for crane, lifeboat, davit and other lifting equipment. With a strong reputation for quality, DOOWIN is considered the first choice supplier by many key industry suppliers, contractors, and end-users.
Our engineers and consultants have been in fabrication and use these products for more than 30 years. DOOWIN has the clients in the Diving, Marine Rescue and Salvage,  Energy and Oil, Offshore  Shipping, and other industries all over the world. DOOWIN products passed rigorous ISO 9001:2008 Quality Management System, approved by the third party SGS, BV, CCS, ABS, LR, BV.

Leading Manufacturer

Our experienced skillful engineer and the quality controller can guarantee the product at good quality and competitive price within the short lead time.

Your Trusted Partner

Your Safety is Our Mission! This has always been our guiding principle in our actions. We focus on all the details. Continuous upgrades and improvements.

The Best Solution Provider

Our experienced engineers are ready to provide you with pre-sales post-sales technical support. On-site guidance services are also available.

Quality Assurance

DOOWIN weight test water bags are dynamic drop test type certificated with 6:1 Safety Factor.
All our proof load bags and air lifting bags meet the standard LEEA 051 and IMCA D016.


air lift bags air tightness inspection

ISO 9001:2008

All produciton process is under control of ISO 9001:2008.

Water Bags Drop Test

UK TUV NEL Drop Test

Our weight bags pass the industry highest test standard.

BV Loading Test

Third Party Certificate

Third-party BV, ABS, LR inspected and approved our products.


Hydraulic Blasting Test

To know its maximum burst pressure and to well know its performance.


IMCA D016 is the international industrial standard for underwater lift bags. Our air lift bags are tested to meet or exceed its safety factor 5:1.


LEEA 051 is the international standard of crane test water bags. It is explicit the requests for the elements of lifting set, which is separate from the water bags, drop test way and pressure test way to verify.

Honesty, Hard Work, Love for Others, Responsibility
Philosophies — “People Oriented, Innovation”

Quality is morality, Quality is integrity, Quality is respect to clients

DOOWIN adhere to the “People Oriented” concept. Pay attention to the application and implementation of the rules. Advocate the core value of “Honest, Hard Work, Love for Others, Responsibility”. And these core values throughout all departments and all kinds of situation management operating standards and business standards. Resolutely oppose the bureaucracy, advocating labor glorious.

underwater air lift bags production
underwater lift bags USA UK customers


Our experienced engineers and workers design and manufactured qualified water bags and salvage bags.
We create outstanding products always. We use the first-class extreme heavy duty polyurethane coated fabric.
The advanced production technology and management system can help to control the cost well, to offer the client the best price. 

Build for Performance

underwater lift bags material test

PVC coating fabric is basic to ensure the water bags and marine salvage airbags work well. DOOWIN uses the equivalent material with UK makers, which is better than some UAS makers, Turkey makers, and Chinese suppliers.

High Quality Accessories

water weight bags accessories

In order to ensure the overall performance of the test weight water bags and lifting air bag system,  we use the high-quality accessories, shackles, master link, water hoses, lifting belts, quick connector. We pursue the perfect of each accessory.

Reasonable Structure Design

crane test water bags design

DOOWIN engineers did the complex strict design and test in order to ensure the best and reasonable water-pressure distribution. Abandoned foreign top-bottom welding technology. Every piece is integral from top to bottom.

Professional Cast Quality

Modec logo

Excellent quality water bags and reliable service, they deliver exactly what they agree to and perfectly on time.

Stephen Barnett, MODEC (Singapore)
China harbor logo

Awesome to use DOOWIN buoyancy bags for our Aramco project. Its quality completely can be comparable with Seaflex lift bags.

Dr.Chen Haijun, China Harbour (Aramcot)
Mcdermott logo

We have confidence with DOOWIN. They can help us with an innovative solution, well prepared to accommodate to our request.

Hugo Silva (Project Manager), McDERMOTT

Do you need a Custom Solution?

Mobile: +86-185 5486 9267 (WhatsApp)
Email: sales@doowincn.com

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