Keywords
Citation
(1999), "Aquablast use kilometre of UHP hose for water blasting project", Anti-Corrosion Methods and Materials, Vol. 46 No. 1. https://doi.org/10.1108/acmm.1999.12846aab.012
Publisher
:Emerald Group Publishing Limited
Copyright © 1999, MCB UP Limited
Aquablast use kilometre of UHP hose for water blasting project
Methods
Aquablast use kilometre of UHP hose for water blasting project
Keywords Polyflex, Surface preparation, Thermoplastics, Wet-blasting
It is reported that Parker Hannifin Polyflex ultra high pressure (UHP) thermoplastic hose has proved to be one of the keystones in the development of novel technology in the surface preparation industry. Subsequently, Polyflex hose is being used in the largest UHP water blasting project to date, currently being carried out, in Greece, by British UHP pump rental and manufacturing company, Aquablast Limited, of Great Yarmouth, Norfolk.
The messy business of open dry abrasive grit blasting for the removal of corrosion and old coatings from structural steelwork is no longer acceptable. Environmental considerations now demand that contractors adopt a cleaner, alternative approach to the problem.
According to Parker waterjet pumping systems operating at pressures of 30,000psi (2,000 bar) and above have now evolved to a stage where virtually any coating or corrosion product can be successfully removed from steel together with highly corrosive salts. This creates an almost perfectly clean surface for repainting using low volumes of fresh water with no dust and hardly any waste material for disposal. However, first, two key problems had to be solved the development of suitable hand-held and automatic water blasting tools, and a flexible means of transmitting water at up to 60,000psi (4,000 bar).
Parker Hannifin's specialist Polyflex Division provided the answer with its now industry-standard range of UHP waterblast hoses supplied by West Midlands based Polyflex distributor, James Lister & Sons. These are now in use round the world, delivering UHP water smoothly and safely in hundreds of heavy-duty industrial cleaning applications.
Polyflex hose cores feature carefully-engineered pressure supports and up to eight high tensile steel wire spiral wraps are applied to the highest pressure hoses. These spiral wraps allow the flexibility which is vital for a UHP gun operator working in a confined space.
British UHP pump rental and manufacturing company, Aquablast, is using more than a kilometre of Polyflex 6105St hose in the preparation of 50,000 sq metres of ballast tanks during the refurbishment of a giant combined ore/oil carrier in the port of Piraeus, in Greece the largest UHP water blasting project to date. The Polyflex UHP hoses not only have to withstand the high pressures, they also have to endure tough handling in a severe dockside environment.
Aquablast engineers are working "round-the-clock", operating up to ten UHP guns, each with up to 100 metres of Polyflex hose running from the UHP pumps located deep in the bowels of the ship.
"The performance of these hoses is critical to the success or failure of projects like these", said Donald Blair, Aquablast's managing director. "They are a relatively high cost item and both the company and the Aquablast gun operators need to have total confidence in the strength and safety of the hose. Given the hostile service conditions we expose this product to, the Polyflex UHP hose performs extremely well. The thermoplastic cover resists abrasion well and the life expectancy of the hose is usually exceeded."
Polyflex hose is designed for pressures up to 320MPa and features low volumetric expansion characteristics which reduces pressure loss, and excellent flex impulse resistance for longer service life.
Aquablast uses Parker Polyflex hoses underwater to Aquablast® pipeline coatings on the bed of the North Sea; inside nuclear reactors where abrasive water jets are used to cut and dismantle radio-active steel; and on hydro-demolition projects involving the removal of decayed concrete on bridge decks and motorway flyovers.
Details from: Parker Hannifin. Tel: +44 (0) 1332 365631.