NEWS

January 2014 Sealing Technology3

B O B ’ S B I T

I would like to wish you all a very Happy New Year. The Christmas and

New Year period will have been quite a challenge for many, with either gales and floods or extremely cold weather, depending on the continent. Such extremes are a very severe test not only for the people involved, but also for a lot of machinery – will it really operate at the extreme end of the design specification?

That thought leads me neatly into test specifications, but more particularly test procedures. I am reminded of this having earlier today noticed the title of a paper to be presented at the High Performance Polymers for Oil & Gas 2014 conference scheduled for April – it is ‘Industry Standards - A Blessing or a Curse?’

One of my recent little jobs has been to review some seal testing – maybe nothing unusual in that. Except that these seals manage to pass a test procedure at one test house, and fail miserably at another. The reason is, of course, that they are actually tested very differently because the proce-dure does not control some important fac-tors affecting how the seal behaves. Which then raises the question: how will they perform in practice?

One test is probably rather more benign than the real application, the other definitely much more severe. But, theoretically all the customer needs is a tick in the box to say the equipment, including the seals, have passed the test.

The soul searching also begins when a further factor is added to the discussion. The testing is specified to the absolute design limit of the specification and in reality the equip-ment will probably never experience these conditions. But, as we have seen recently, it might. Some areas of the UK have experi-enced a 100 year flood three times in the last three months.

What is the seal industry doing to make things better? We have, as usual, plenty of developments. But there is still plenty of opportunity to make progress. The discussion session at the 22nd International Conference on Fluid Sealing, (see page 9), produced some of the most animated discussion I have ever seen at a conference of this type, and particu-larly the presentation on aircraft cabin air. But it is not just a matter of sealing expertise. It requires recognition and will on the part of aircraft operators, certification authorities, governments and, of course, engine manufacturers.

Bob Flitney

‘‘Waterless’’ dyeing system employs Saint-Gobain’s seals

Over the past few years US-based Saint-Gobain Performance Plastics’

Seals Group has been working closely with Dutch company DyeCoo Textile Systems Bv to develop sealing technol-ogy for environment-friendly industrial dyeing machines that use CO2 instead of water in processes used to add col-our to fibres, yarns and fabrics.

Industrial dye machines based on ‘‘waterless’’ dyeing technology heat CO2 until it has the properties of both a liquid and a gas, at which point it penetrates the fabric and diffuses pig-ment throughout the material. As it returns to its gaseous state, 95% of the gas can be recycled for further use, saving billions of litres of water and avoiding billions of gallons of toxic chemi-cals being dumped into waterways.

The company’s Seals Group was approached by DyeCoo to find a way of sealing CO2 under a pressure of up to 400 bar (40 MPa) and temperature up to 120°C. These condi-tions pose a major challenge to ordinary seals and, in most cases, they fail when exposed to extreme environments.

The group’s engineers developed a custom version of its spring-energised OmniSeal product. The seal jacket is manufactured from Fluoroloy, a proprietary polytetrafluoroethylene (PTFE) compound, and features a specially formed spring to activate the seal.

The custom seal is used on the doors of the industrial dye machines and prevents the grow-ing extrusion gap whenever the pressure in the vessel rises (essentially solving big tolerance issues caused by the high pressure). Rigorous testing confirmed that the approached based on OmniSeal produced optimum results and DyeCoo is currently using this robust product in all of its machines. It says that by using this sealing technology it has been able to continue its mission of contributing to a sustainable environment in terms of water and energy con-sumption, CO2 emissions and waste disposal.

Contacts:

Saint-Gobain Seals Group, 7301 Orangewood Avenue,

Garden Grove, CA 92841, USA. Tel: +1 714 995l 1818,

Fax: +1 714 688 2800, Web: www.seals.saint-gobain.com

Saint-Gobain Performance Plastics Nv,

22 Heiveldekens, 2550 Kontich, Belgium.

Tel: +32 3 458 2828, Fax: +32 3 450 6601,

Web: www.plastics.saint-gobain.com

DyeCoo Textile Systems Bv, Flevolaan 50, 1382 JZ

Weesp, The Netherlands. Tel: +31 294 41 00 25,

Fax: +31 8422 99 357, Email: info@dyecoo.com

Web: www.dyecoo.com

SKF launches HSS seals for the metals- processing industry

SKF is introducing a range of reinforced, all-rubber HSS seals

that are targeted at the metals- processing industry.

The supplier of bearings, seals, mechatron-ics, lubrication systems, and maintenance services, says the seals, which are easy to install in mill stand chocks will help plant operators improve reliability and productivity.

This seal range features a new concept of seal reinforcement and is SKF’s new preferred product for large-size bearing protection in metal-making assets.

‘Seals are often perceived as commodity items. In reality, they are essential system components that help to ensure bearing and system performance, reliability and efficiency. When installed as part of an optimised bear-ing arrangement HSS seals offer mills a way of upgrading asset performance, boosting overall mill reliability and productivity, and cutting costs per tonne,’ said Robert Blachfellner, Global Product Manager, Industrial Seals Segment, SKF.

SKF’s HSS seals offer mills operating in the metals-processing industry a way of upgrading asset performance, and boosting overall reliability and productivity.