Ship Lifting And Refloating Rubber Salvage Airbag

Product Introduction:

The rubber salvage airbag is a buoyancy assist airbag made by Qingdao Shunhang Marine Supplies Co., Ltd. according to the demand characteristics of the salvage project. Underwater salvage projects generally have the characteristics of complicated operations, high costs, and strict requirements on equipment and personnel. How can salvage projects save time and effort? Shunhang marine supplies technicians designed this inflatable float-assisting and salvaging airbag after dedicated research.

Inflatable buoyancy and salvage airbags have the advantages of light weight, strong air retention performance, deep water pressure resistance and convenient carrying. Therefore, it is widely used in salvage projects such as sunken ship salvage, stranded ship, pontoon bridge, caisson, etc.

The conventional diameter of the airbag can be 0.5m-2.5m, the length can be 5-28m, and the number of layers can be 4-12. Other models can also be produced according to customer needs. The structure of the airbag is composed of the airbag body and the end iron parts. The bladder wall is made of natural rubber and nylon cord fabric through vulcanization; the end iron piece is made of metal material, and the surrounding is tightly combined with the bladder. Each air bag is equipped with a set of inflation valve, pressure gauge, wire connection, tendon pad, wire loop, and wire mouth.

Features of Rubber Salvage Airbags
Not easy to be affected to wind and wave.
Less demand of binding.
Easy to meet the needs of buoyancy ranging from 100 tons to 2000 tons.
Easy to transport and store while the airbags are deflated.
Super-high tensile strength owing to its framework material - heavy-duty synthetic-tire-cord layers with breaking strength about more than 15,000 N/ 5cm.
Excellent resistance against abrasion and scratch.
Low maintenance.
High flexibility and cost effectiveness.

Specifications Of Rubber Salvage Airbags:

Attention During Application

1) Working pressure must be controlled strictly, it is not allowed to exceed the working pressure.
2) No sharp and protruding hard object on the contacting surface of the airbags, to avoid the puncture on the skin of airbags.
3) Avoid the distortion along the length of airbag.
4) Empty inflating test must be performed if the airbags were not used for a long time or after reparation. The pressure should be as same as the testing pressure of our company. Inspectors must be at least 3 meters away from the airbags. For repaired airbag which was damaged in large scale, its working pressure should be lowered reasonably. Besides, annual check should be conducted on airbags which are used frequently.
5) Don’t drag the airbags on the ground.

Instruction of Airbag Repair

If the airbag is damaged, it can be repaired as long as the rubber doesn’t age seriously(with no crack and stickiness on the surface). And the cords fabric is not loose and rotten. Repair can be made by hot vulcanization or auto-vulcanization. The tolls and repair materials utilized in the former are quite simple. We recommend hot vulcanization, the steps are as below,

1. Wash the airbags to make sure it is clean both inside and outside and without mud & sand,
oil stain and water logging. Then dry the surface. Note: the immersion time while washing can’t more than 10 minutes.
2. Mark the repair symbol visibly. Mark the repair area and the mark area is allowed to exceed 15mm, don’t miss the concealed damage.
3. Prepare the backing
The material of backing is the same as the airbag and the arrangement angle of the cord fabric is consistent with the airbag.
The first layer of the backing is a vertical line. Length=(length of the flaw+50mm)X2
The second layer of the backing is oblique line whose angle is the same as the airbag. It is 20mm larger than the periphery of the first layer.
The third layer of the backing is also oblique line whose angle is opposite to and crosses with the second layer. It is 20mm large than the periphery of the second layer.
The fourth, fifth and sixth layer may be deduced by analog.
The fillet transition with the radius of 40mm-50mm is required for the backing periphery of every layer.
If the wound is a nail hole within 100mm or strip wound in 50-70mm, cross backing shall be prepared. Nylon cross backing is made by bluing two layers of coated Nylon with the crossing of 90°. Its size is 200mmX200mm and others are the same as the backing.
4. Filing the wound
File the wound with steel files or flexible shaft filing machine. The file pattern on the surface should be delicate and even as well as without any rubber scrap, particle. Filing surface depth is about 0.5-1mm. The periphery is 20mm larger than the backing. Breaking and loose is not allowed for filed cord fabric. After filing, blow always the rubber scrap by brush and compressed air.
5. Brush glue and dry
The whole process must be kept clean. Brush thin glue for the first time (glue: gasoline=1:8).There should be no sediment and caking, should be evenly. Forcibly gluing should be performed so that the glue can penetrate into the cord fabric layer in the file slot. The gluing should be uniform and obvious scaffold erecting is not allowed.
6. Viscose
Firstly, brush a layer of base glue with the thickness of 1±0.2mm on the periphery of the wound. Cool down to not gluing hands, paste and press and the glue should not be too tight in case glue failure happens after the new glue contract, then paste the backing. The center of the backing should be targeted at the wound center. The angle of the backing should be in consistent with the airbag line layer. For wound larger than 1M, a layer of coated Nylon fabric should be pasted to the wound, 25mm lager than the wound. Then paste the backing. In the end, one sealing rubber (thickness of 0.8-1mm,wideth in 20mm) should be pasted to the cover the joint of backing edge and body of airbag.
7. Vulcanization
For normal shipbuilding yard, the following simple method can be adopted: set up a frame, ( as shown in the figure) and provide plate, sand bag(fill the inner tube of the abandoned automobile with sand), jack and heated plate(pig iron or steel plate in Dia300mm ,thickness 25mm). The vulcanized airbag to be repaired should be targeted to the center in accordance with the position shown in the figure. First vulcanize the hole and then the wound. If the large wound to be vulcanized exceeds the effective length of the vulcanization, the center should be vulcanized firstly then both sides. The heated plates should overlap 15mm with the previous position in re-vulcanization. The vulcanization shall be finished within 40-50 minutes when the temperature rises to 135±5℃ and pressure is 0.8-0.12MPa.
8. Check whether the repair is bound tightly or not, Flaw such as void, delaminating or sponge and so on are not allowed. As to new glue in heating area, aging, crack, under vulcanization and over vulcanization is not allowed. Inflating test shall be conducted if the repair is qualified.

Storage of The Rubber Salvage Airbags

1) If the airbags won’t be used for quite a long time, it shall be washed and dried, filled with talcum powder inside and coated with talcum powder outside, place it in dry, shady and ventilated place in the warehouse.
2) Place string the airbags should be far away from the heat source.
3) The temperature of the warehouse should be kept no more than 30℃.
4) Keep the airbags away from acid, alkali, grease and organic solvent.
5) The airbags should be stretched flat when not used. It is not allowed to pile up and stack heavy object on the airbag.

Qingdao Shunhang Marine Supplies Co.,Ltd. located in Qingdao ,China. Our company was established in 2011, specialized in manufacturing marine rubber airbags ,pneumatic rubber fender,EVA foam filled fenders.

Our company has passed ISO9001 certificate. Our products have approved by CCS, BV, ABS, RS, SGS etc.

We have established long-term cooperative relationship with many shipyards, ship owners and trading companies . Our products have been exported to Southeast Asia,Middle East, Africa, South America and European markets. etc. many countries and regions.