Tag Archives: technetics

Inflatable Seals

Designing with inflatable seals for the medical industry

Seals are central parts of the design of medical equipment with moveable, interlocking parts that must be secured for sanitary, thermal, or radioactive reasons.

Designing with inflatable seals requires the inclusion of a source of compressed gas, which is used to inflate seals in the medical device industry and it is often already available on the plant floor, in a laboratory, or medical environment. It is also possible to inflate with liquids rather than gas in demanding applications, and water would be an acceptable inflation media in this sector, although not common. For some low-temperature applications, a seal may be inflated with a blend of glycerine and water.

Designing with inflatable seals

Seals used on doors and openings should be part of the early phases of product design. In some cases, contact seals may be effective, but they often require substantial force be applied to load the seal, which impacts product design and increases manufacturing cost. Inflatable seals enable more cost-effective machinery fabrication for two reasons:

  1. Inflatable seals are more forgiving because the seal can inflate to close a gap between structural members and achieve equal sealing pressure around the flange as long if the gap falls within a broad tolerance. An inflatable seal will work whether the gap spans 3mm or 10mm, for instance. A compression seal or other contact seal will not be effective unless the seal and flange contact each other with great precision, which can be difficult to achieve on new equipment. Even a robust and precision-manufactured machine with well-designed flanges will lose some of its geometric integrity as hinges and other components deform or bend over years of use. Throughout the course of the equipment lifecycle, a contact seal may become problematic and exhibit leakage.
  2. Inflatable seals enable lighter and more affordable methods of equipment fabrication. The force exerted on the chassis of a piece of equipment means doors and related components must be thicker, and perhaps machined instead of welded. These components are typically made of stainless steel, and inflatable seals might be attractive due to lowered material costs.

Which equipment needs inflatable seals?

  • Isolators — where a leak-tight enclosure can be critical for environmental health protection due to hazardous substances or processes. — can secure glove boxes, access gates, transfer systems and filtration systems that handle toxic or sterile components.
  • Sterilizers — which may rely on heat, chemicals, irradiation, or filtration — may be suitable for desktop autoclave sterilizers, sterilizing tabletop autoclaves and static air depyrogenation sterilizers.
  • Dryers and freeze dryers – used to sterilize everything from machine components to glassware.
  • Material handling functions – to raise, lower, or grasp objects.

Continue reading Inflatable Seals

Sealing Solutions for Subsea Systems in the North Sea

Innovative Subsea Processing Technologies

The Aasgard oil and gas field in the North Sea has been operating since 1999. Innovative subsea processing technologies were used to compress the oil and gas on the site’s seabed to improve recovery rates as the field ages and as equipment begins to draw from increasingly deeper subsea reservoirs. The operator required seals for the lid and body of the control power distribution unit in order to protect its vital electronics in the harsh, unforgiving subsea environment.

As a globally trusted source for engineered components, seals, assemblies, and sub-systems for demanding environments, Technetics was uniquely positioned to evaluate and specify a sealing solution for this application. The system designer and Technetics engineers subsequently underwent a two-year testing phase to examine the performance of a variety of sealing options.

Demanding Subsea Environment

Due to the extremely demanding environment in which the subsea Subsea Techneticspressure vessel would be operating, finding a sealing solution that would meet both the operator’s and governmental requirements turned out to be lengthy and complex. Specifically, the operator noted that the seal needed to meet high-pressure requirements with a strict leak rate of 10-11 cc/sec He for a period in excess of 10 years.

Based on the extensive testing results, Technetics identified a HELICOFLEX® spring energized metal seal as the ideal sealing solution. The HELICOFLEX® seal consists of a close-wound helical spring core and outer jacket material that provides a highly ductile and plastic sealing surface. This combination of materials allows it to provide consistent and reliable sealing performance under uneven flange pressures and imperfections in the flange surface. Benefits of the HELICOFLEX® seal include helium tightness, long seal life, and excellent corrosion resistance.

This solution not only secured the electronic equipment inside the vessel, but it also alleviated any environmental and safety concerns from potential leakage and failure of the system. Thus, the installation of the HELICOFLEX® spring energized metal seal provided the required sealing integrity.

To learn more about the HELICOFLEX® seal, download the HELICOFLEX® seal PDF.


The original article can be found on Technetics’ website.

To learn more about Technetics products, speak to a Gallagher representative today by calling 1-800-822-4063