Flexitanks are temporary storage facilities that can be towed along side a vessel in the water.
Information about Flexitank products can be found below. If further information is required please [contact Abar Solutions] for assistance.
- Standard capacity range between 5 and 100 tonnes.
- As well as for oil, the tanks can be made to order for use to store potable water and chemicals.
- Flexitanks are a perfect ancilliary to force 5 and force 7 oil recovery systems.
General Description
The TOWED FLEXIBLE STORAGE TANKS are available in various sizes and consist of a long cylindrical bag with a tapered nose constructed from high tenacity nylon fabric coated each side with polyurethane.
All seams are glued welded and stitched where necessary, and sealed with tapes, also of polyurethane coated nylon cloth. The tapered nose is finished with a strong aluminium fabrication to which the tow rope is shackled.
The tail of the cylinder is less finely tapered and is closed by means of aluminium clamps which, when removed, allow the T.F.S.T to be entered for cleaning and inspection.
5 tonne flexitank compact
The T.F.S.T floats at the surface when loaded with a cargo, having density less than that of the surrounding water and, because of built-in buoyancy, it also floats when empty and therefore may be easily towed or moored if required in the unloaded condition.
Loading
Filling is by means of flexible hoses attached to the upper surface of the T.F.S.T in such a position that it may be easily reached when the T.F.S.T is lying alongside the towing Vessel.
Close up of flexible hose connection
There is a screw-down vent valve to bleed off any air that may become trapped in the container during the pumping operation.
Flexitank screw down vent
The T.F.S.T are designed to accept the stated nominal carrying capacity of liquid at 80% of their absolute maximum capacity. This is because 80% full is the optimum state for containers of this type in order to reduce surging and porpoising in sea states.
Discharging
Cargo is removed from the containers by using a positive displacement pump connected to the loading/discharge hose and pumping out with the air bleed valve closed.
Close up of mooring rope
Cleaning
The outside of the T.F.S.T can be cleaned with a high pressure water hose, scrubbing brushes and detergent.
To clean the inside, the T.F.S.T should be laid out on a flat surface and a small quantity (about 500 litres) of water/detergent mixture pumped into it. This can be agitated inside the T.F.S.T by treading it well before discharging it.
For more thorough cleaning, inspection or repair purposes, the end fitting may be removed by undoing the bolts at either end of the clamping bars on the nose and tail.
The T.F.S.T can then be partially inflated by means of a low pressure blower attached to the nose and an Operator, wearing suitable protective clothing, can then climb into the tail.
Normal precautions should be taken to avoid risk of fire or explosion, and it should be borne in mind that some oil fuels contain toxic chemicals such as lead and that in some cases, the fumes can also be dangerous. The normal precautions necessary when entering a tank that has contained oil fuel should naturally be taken.
Repair
In the event of damage, the T.F.S.T is relatively easily repaired. It is necessary to dry and thoroughly clean the material adjacent to the damage before starting the repair. A sealing kit is supplied with each T.F.S.T and includes sealing tape, spare fabric, solvent, adhesive and instructions to enable minor repairs to be effected. If major damage is incurred we should be consulted.
Removing aluminium clamping bars
These bars are situated at the tail of the T.F.S.T. and in their relaxed state are bowed approximately 30mm. When they are clamped together they a pulled straight and provide a uniform clamping force between the bolts. To avoid the use of overlong bolts which would stick out beyond the clamping bars, they are assembled using G-Clamps. The nuts should therefore only be undone after G-Clamps are used to prevent the bars from springing apart which would happen with considerable force if the nuts are merely undone, and this could be extremely dangerous.
For inland and shoreline spill recovery storage containers, see Pillow Tanks.
