Specialists in marine air lift buoyancy bags and water load test weights
Seaflex often receives requests where specific functions are required. One was to propose a buoyancy system to float three 2.5km strings of concrete coated LNG pipelines in a bundle through a tributary in Soyo, Angola.
Diver less Buoyancy Release System
But it was also important to provide a quick release system which would allow the buoyancy units to be safely removed from the pipeline without the use of divers. Not too unusual a request and the answer was a combination of 660 Seaflex 5 ton Mono Buoyancy Units (MBUs) with a simple release Sea Catch TR7 for each buoyancy unit.
Once the pipelines were towed into position, the air was released from the bags to allow the pipelines to settle on the river bed. The deflated bags were then disconnected from the pipeline by pulling the Sea Catch release lanyard at the surface.
Every year, Unique Seaflex gets involved in renting our Mono Buoyancy Units out for more and more such projects around the world.
Because HDPE pipe is intrinsically buoyant, and offers more than enough reserve buoyancy to support the concrete collars when the ends are capped, it may mulberry purse not always be apparent that the mulberry purse use of additional buoyancy units can be a vital part of this process when it comes to the easy positioning and joining of multiple pipe strings. So underneath we provide an illustrated guide to this process.
1. Construct string of HDPE pipe ashore complete with concrete collars every few metres
2. Cap off both ends with blanking flanges
3. Roll string into water un mulberry purse til just floating
4. Install MBUs to collars see attachment method below.
Capped off HDPE pipe, fitted with deflated Mono Buoyancy Units
5. the end of the previously installed string.
Launched HDPE pipe being towed into position
And is manoeuvred to the end of the previous string, where the MBUs are inflated before the pipe is flooded.
6. Flood pipe by opening water inlet on the offshore blanking flange until it starts to submerge
7. Bleed air out of the upper vent valve on the shore end to control the flooding of the pipe
8. Complete string sinks until it is ‘caught’ mid water on the MBUs connected above the collars (or pipe) with webbing slings at pre determined lengths.
9. Position the string as close to the last string as possible before venting the MBU’s at the shore end allowing it to gently rest on the seabed.
10. Continue venting all bags until the string is positioned on the seabed.
12. Adjust the buoyancy developed by the MBUs in order to facilitate the final positioning using tirfors / winches.
13. Deflate and remove bags for use with next string
Easy! Although Seaflex BOSIET ticketed technicians are always available to tr mulberry purse avel worldwide to advise and assist in the use of our products on such projects.
Please contact us to find out more about how how Seaflex can assist you with your HDPE pipe installation projects.
A Growing Application for As part of the commissioning and testing of new trains it is essential that the brakes are checked. To do this the train must run at a set speed along the track and stop within a given distance. To fully test under normal conditions the carriages need to be loaded as if they were occupied by passengers. For obvious reasons people cannot be used for this test.
Train brake load testing showing water filled bag this has been done by manually loading carriages with items such as bags of sand or shingle to achieve the necessary weight to simulate a full payload of passengers or cargo.
However,this is highly labour intensive when dozens oftons of ballast is required, and if any of those bags split then it does tend to make a bit of a mess of a brand new train leading to even moretime and money being spent on a clean up exercise.
There is now an easy alternative: the use of water filled bags to provide the necessary amount of weight for the test.