NEWS

August 2013 Sealing Technology3

B O B ’ S B I T

A brief email message arrived as I was contemplating this column,

informing me that 124 years this month a Dan Rylands of Hope Glass Works in Yorkshire patented the first screw bottle top.

In fact, the reason for the email was to advertise rapid prototyping technology, but that just helps to emphasise how technology progresses. Screw bottle caps with moulded-in seals are a long way from the cut seals crimped into caps that were common not very long ago. And now the bottle itself can be made from a range of materials some of which are much younger than this patent.

But what do we have this month? Our two technical features both discuss rotary seals, but very different types of seal and application.

Both are good examples of sealing tech-nologies being applied to an application where lack of availability of a suitable seal has been a limiting factor in the application of the technology.

Multiphase pumping has been a difficult application for both pumps and seals for many years. It is interesting that modern materials technology is helping to reduce auxiliary equipment and improve reliability. Both are important as these pumps will, by definition, almost always be located in a challenging environment.

Our feature on a new development in PTFE lip seals also reflects an important trend. Quite often an application needs a reli-able rotary seal, but a mechanical seal may be unacceptable because of weight, cost or space limitations. I think it interesting that devel-opments such as this are moving at least some way to bridge that gap between lip seals and mechanical seals.

Among other developments we have gasket materials and as always with gaskets the bolt-ing is critical, and so our cover news item on a quick-release system for ROV operation is particularly interesting.

When it comes to elastomer materials it is easy to think that all the development is focused on extreme applications, such as the materials for sour gas discussed in the news. But NBR material is still important, and so developments that extend its range of opera-tion and facilitate production are probably of greater overall impact.

Something about which I know very little is the large integrated software packages such as those described. Presumably they should include factors concerned with seals, but in how much detail? I would be interested to learn of any experience readers may have.

Bob Flitney

Proportioner (AGP). This unit is designed to solve the inherent challenges of on-ratio mixing for silicones that are often used in manufacturing insulating glass, and curtain-wall systems which form the covering for non-structural outer walls of some buildings.

The AGP’s real-time ratio assurance also reduces material waste because it automatically shuts down if off-ratio conditions occur.

‘Accurate mixing of plural-component adhe-sive materials is vital in the creation of insulat-ing glass units and curtain-wall,’ said Mike Cryer, Product Marketing Manager, Graco.

‘Obtaining on-ratio mixing and dispens-ing for these applications has long proven to be a difficult industry challenge, but the ExactaBlend AGP offers ratio assurance and is an affordable, high-quality system that offers attractive savings to the end-user.’

In addition to reducing costs and offering quality assurance benefits, the AGP is also easy to operate. Compared with traditional pro-portioners with mechanical linkage and rocker arms, the unit’s electronic controls remove the guesswork from ratio setting and maintenance. They enable ratios to be set up easily and ratio changes to be made on the fly.

Contact:

Graco Inc, Russell J. Gray Technical Center, 88–11th

Avenue Northeast, Minneapolis, MN 55413, USA.

Tel: +1 612 623 6000, Fax: +1 612 623 6777,

Web: www.exactablend.com, Web: www.graco.com

Data-transmission connectors endure high-pressure cleaning

Belden Inc, a US company that specialises in signal-transmission

products and technology for mission-critical applications, has launched new Lumberg Automation brand wash-down connectors. It says they guar-antee reliable data transmission even under harsh environmental conditions, which ensures that equipment contin-ues to run smoothly.

Optionally available as single-ended or double-ended actuator or sensor cord sets, these connectors have an M8 or M12 thread and a hexagonal stainless steel coupling nut.

Resistant to aggressive chemicals and clean-ing agents, they have an operating temperature

protection. This enables them to endure high-

pressure cleaning and, therefore, they are suitable for use in areas where stringent rules of hygiene apply – that is, in the food and beverage sector, chemicals and pharmaceuticals industries. Other features include gold-plated crimp contacts; high shock and vibration resist-ance, and simple installation.

The connectors are available in versions with -

tact resistance � 5 m�. Nominal current, rated voltage and rated impulse voltage comply with DIN EN 61076-2-101 and DIN EN 61076-

Contact:

Belden Inc, 7733 Forsyth Boulevard, Suite 800,

St Louis, Missouri, USA. Tel: +1 314 854 8000,

Fax: +1 314 854 8001, Web: www.belden.com,

Web: www.lumberg-automation.com

Hydratight launches pneumatic torque wrenches

Joint integrity company Hydratight Ltd has added five pneumatic

torque tools to its range of hydraulic torque wrenches.

Designed for accurate torque control, the tools’ two-speed gearbox produces quick nut-run-down times, says the firm. In addition, the operators’ hand-force is negligible, with

existing tooling.

compared with other systems that are currently

or 50 cfm. This will enable the pneumatic torque range to be expanded and applied to more areas, including remote field applications.

‘The pistol grip swivel, based on an ergo-nomic design, ensures that the user can produce torque up to 5000 ft.lbs with minimal impact,’ commented Chad Brooks, Global Product Manager, Hydratight.

‘We are pleased with how the product has performed in our extensive validation testing. This new range will sit comfortably within our existing portfolio of robust, reliable and market leading tooling.’

Contacts:

Hydratight Ltd, Bentley Road South, Darlaston, West

Midlands WS10 8LQ, UK. Tel: +44 121 5050600,

Fax: +44 121 5050800, www.hydratight.com

Hydratight, 1102 Hall Court, Deer Park, TX 77536, USA.

Tel: +1 713 860 4200, Fax: +1 713 860 4201,

Email: houston@hydratight.com