- Email: [email protected]
Website provides information on biocompatiblity
NEWS
Calculation of brush seal leakage PerkinElmer Fluid Sciences has released an engineering tool that allows its customers to estimate brush seal performance in many types of turbomachinery. The performance predictor is designed to simplify the application of brush seal technology, by allowing customers to evaluate seal performance. The user can input specific pressure and temperature conditions, and the software predicts the leakage performance of the turbomachinery system. The aim is to permit rapid evaluation of the potential benefits of the brush seals provided by the company, and to provide a considerably reduced lead time from evaluation to installation. ‘The brush seal performance predictor is a very handy and easyto-use program for estimating leakage of brush seals,’ says Ted Gresh, a senior consulting engineer at
Elliot Turbomachinery Company. ‘Using this program along with a program like Laby Flex by Flexware, makes it easy to determine the savings involved in converting to brush seals.’ Contact: Perkin Elmer Fluid Sciences, 5209 Rising Sun Lane, Ellicott City, MD 21043, USA. Tel: +1 410 461 5659, Fax: +1 410 461 5109, Email: al.deamer@perkinelmer. com, Web: fluidsciences.perkinelmer.com
Editor’s comment: I have tried this, and it is certainly very convenient to use. It is, for example, possible to quickly scan the effect of changing the operating conditions. If data are available for alternative seal types, it is then very convenient to compare the results. I presume that the calculations are based on either proven science or established empirical data.
Website provides information on biocompatiblity In the fields of medical devices, pharmaceutical processing and biological engineering there has been an increasing demand for sealing with biocompatibility. However, O-rings and the standards for biocompatible rubber products are unfamiliar to many designers. Now a new website from Kentucky-based Molding Solutions provides a central location for this information. When rubber is required to be biocompatible, the best materials are classified as ‘USP Class VI’. This term is reserved for materials that have passed a series of tests showing that the materials do not generate reactions in mammals, and is the highest of the six levels required by the USP procedure. To provide users with a single resource for information associated with USP Class VI O-Rings, Molding Solutions has created a website dedicated to this product. The website contains information about the US and international standards applicable to these O-rings, O-ring dimensional data, product information and available sizes.
Sealing Technology November 2004
Contact: Molding Solutions, 781 Enterprise Drive, Lexington, KY 40510, USA. Tel: +1 859 231 0031, Fax: +1 859 254 8884, Web: www.class-vi-o-rings.com
Editor’s comment: To save readers a little time, the standards information provided on this website is as follows: • SAE AS568 — ‘Aerospace Size Standard for O-Rings’ is the ‘bible’ of standard O-ring sizes. It lists hundreds of O-ring sizes with their dimensional tolerances. • USP 23 <88> — ‘Biological Reactivity Tests, In Vivo’ contains testing procedures for rubber and plastics that will be used in direct or indirect contact with humans or animals. The strictest set of testing requirements is identified as ‘Class VI’. • ISO 10993 — An International standard for ‘Biological Evaluation of Medical Devices’. Contains test methods for materials to be used in medical devices. This standard identifies test requirements based on specific applications and usage of the end product.
Terminal seals made in new molds DP Seals has recently completed the design and production of protective rubber bumpers and gaskets for the OT40 and PT60 ranges of handheld terminals made by Oyster Terminals UK Ltd. The project is one of the first that is possible because of two new molding presses, which enable the company to produce components of up to three times the size and thickness of those available previously. Designed to be very robust, the OT40 is capable of withstanding rough industrial handling, including a 1 m drop onto concrete. The nitrile rubber bumper provides the shock protection if the unit is accidentally dropped, as well as protecting the Xenoy case.
These terminals may be fitted with special rubber sealing gaskets, also manufactured by DP Seals, which provide water and dust sealing to IP65. Developed to a precise brief from Oyster’s engineers, the bumper incorporates PVC additives that enhance appearance and help meet the performance requirements for handheld equipment being used in factories, theaters, workshops and warehouses. Contact: DP Seals Ltd, Unit 6 – Dawkins Road, Hamworthy, Poole, Dorset BH15 4JY, UK. Tel: +44 1202 674671, Fax: +44 1202 665581, Email: [email protected], Web: www.dpseals.com
Poorly installed gasket causes ammonia leak A toxic cloud of ammonia which leaked from McCain Foods’ Wendouree factory in Australia was likely to be a one-off incident, according to investigators. The Victorian WorkCover Authority and Environmental Protection Agency discovered that a gasket in an ammonia pipe to the rear of the plant was poorly installed, according to a report in the Ballarat Courier in Victoria. People were asked to stay indoors and roads were blocked as Country Fire Authority crews worked for
more than two hours to contain the leak at the plant. The investigators concluded that the incident was caused by the failure of a gasket within an ammonia pipeline, rather than improper operating practices. A WorkCover spokesman said the findings were different to early investigations; it was initially thought that a safety lockout valve had failed. The company is seeking external assistance to put in place measures to prevent further incidents. It is thought that the problem occurred during the installation of the freezer.
PPS material delivers economical yet reliable performance Equipment manufactured by De Smet for a number of aggressive environments is being fitted with bushing rings of Techtron HPV PPS material from Quadrant Engineering Plastic Products. The equipment includes machinery for oil extraction, protein meal production and refining to vegetable oil, protein meal, and protein isolate production. The reinforced, internally lubricated polyphenylene sulfide (PPS) grade, Techtron HPV PPS, demonstrates a suitable combination of properties including wear resistance, load-bearing capabilities and dimensional stability when exposed to chemicals and high-temperature environments.
The material is claimed to overcome the disadvantages of virgin PPS, caused by a high coefficient of friction, and of glass-fiber reinforced PPS, which can cause premature wear of the counter face in movingpart applications. The combination of wear resistance, friction and fluid compatibility provides an improvement over conventional plastics such as PA and POM, but a more economical solution than higher-grade plastics such as PEEK. Contact: Quadrant Engineering Plastic Products, IP Noord – R. Tavernierlaan 2, B-8700 Tielt, Belgium. Tel: +32 51 423571, Fax: +32 51 423570, Email: [email protected]
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Calculation of brush seal leakage PerkinElmer Fluid Sciences has released an engineering tool that allows its customers to estimate brush seal performance in many types of turbomachinery. The performance predictor is designed to simplify the application of brush seal technology, by allowing customers to evaluate seal performance. The user can input specific pressure and temperature conditions, and the software predicts the leakage performance of the turbomachinery system. The aim is to permit rapid evaluation of the potential benefits of the brush seals provided by the company, and to provide a considerably reduced lead time from evaluation to installation. ‘The brush seal performance predictor is a very handy and easyto-use program for estimating leakage of brush seals,’ says Ted Gresh, a senior consulting engineer at
Elliot Turbomachinery Company. ‘Using this program along with a program like Laby Flex by Flexware, makes it easy to determine the savings involved in converting to brush seals.’ Contact: Perkin Elmer Fluid Sciences, 5209 Rising Sun Lane, Ellicott City, MD 21043, USA. Tel: +1 410 461 5659, Fax: +1 410 461 5109, Email: al.deamer@perkinelmer. com, Web: fluidsciences.perkinelmer.com
Editor’s comment: I have tried this, and it is certainly very convenient to use. It is, for example, possible to quickly scan the effect of changing the operating conditions. If data are available for alternative seal types, it is then very convenient to compare the results. I presume that the calculations are based on either proven science or established empirical data.
Website provides information on biocompatiblity In the fields of medical devices, pharmaceutical processing and biological engineering there has been an increasing demand for sealing with biocompatibility. However, O-rings and the standards for biocompatible rubber products are unfamiliar to many designers. Now a new website from Kentucky-based Molding Solutions provides a central location for this information. When rubber is required to be biocompatible, the best materials are classified as ‘USP Class VI’. This term is reserved for materials that have passed a series of tests showing that the materials do not generate reactions in mammals, and is the highest of the six levels required by the USP procedure. To provide users with a single resource for information associated with USP Class VI O-Rings, Molding Solutions has created a website dedicated to this product. The website contains information about the US and international standards applicable to these O-rings, O-ring dimensional data, product information and available sizes.
Sealing Technology November 2004
Contact: Molding Solutions, 781 Enterprise Drive, Lexington, KY 40510, USA. Tel: +1 859 231 0031, Fax: +1 859 254 8884, Web: www.class-vi-o-rings.com
Editor’s comment: To save readers a little time, the standards information provided on this website is as follows: • SAE AS568 — ‘Aerospace Size Standard for O-Rings’ is the ‘bible’ of standard O-ring sizes. It lists hundreds of O-ring sizes with their dimensional tolerances. • USP 23 <88> — ‘Biological Reactivity Tests, In Vivo’ contains testing procedures for rubber and plastics that will be used in direct or indirect contact with humans or animals. The strictest set of testing requirements is identified as ‘Class VI’. • ISO 10993 — An International standard for ‘Biological Evaluation of Medical Devices’. Contains test methods for materials to be used in medical devices. This standard identifies test requirements based on specific applications and usage of the end product.
Terminal seals made in new molds DP Seals has recently completed the design and production of protective rubber bumpers and gaskets for the OT40 and PT60 ranges of handheld terminals made by Oyster Terminals UK Ltd. The project is one of the first that is possible because of two new molding presses, which enable the company to produce components of up to three times the size and thickness of those available previously. Designed to be very robust, the OT40 is capable of withstanding rough industrial handling, including a 1 m drop onto concrete. The nitrile rubber bumper provides the shock protection if the unit is accidentally dropped, as well as protecting the Xenoy case.
These terminals may be fitted with special rubber sealing gaskets, also manufactured by DP Seals, which provide water and dust sealing to IP65. Developed to a precise brief from Oyster’s engineers, the bumper incorporates PVC additives that enhance appearance and help meet the performance requirements for handheld equipment being used in factories, theaters, workshops and warehouses. Contact: DP Seals Ltd, Unit 6 – Dawkins Road, Hamworthy, Poole, Dorset BH15 4JY, UK. Tel: +44 1202 674671, Fax: +44 1202 665581, Email: [email protected], Web: www.dpseals.com
Poorly installed gasket causes ammonia leak A toxic cloud of ammonia which leaked from McCain Foods’ Wendouree factory in Australia was likely to be a one-off incident, according to investigators. The Victorian WorkCover Authority and Environmental Protection Agency discovered that a gasket in an ammonia pipe to the rear of the plant was poorly installed, according to a report in the Ballarat Courier in Victoria. People were asked to stay indoors and roads were blocked as Country Fire Authority crews worked for
more than two hours to contain the leak at the plant. The investigators concluded that the incident was caused by the failure of a gasket within an ammonia pipeline, rather than improper operating practices. A WorkCover spokesman said the findings were different to early investigations; it was initially thought that a safety lockout valve had failed. The company is seeking external assistance to put in place measures to prevent further incidents. It is thought that the problem occurred during the installation of the freezer.
PPS material delivers economical yet reliable performance Equipment manufactured by De Smet for a number of aggressive environments is being fitted with bushing rings of Techtron HPV PPS material from Quadrant Engineering Plastic Products. The equipment includes machinery for oil extraction, protein meal production and refining to vegetable oil, protein meal, and protein isolate production. The reinforced, internally lubricated polyphenylene sulfide (PPS) grade, Techtron HPV PPS, demonstrates a suitable combination of properties including wear resistance, load-bearing capabilities and dimensional stability when exposed to chemicals and high-temperature environments.
The material is claimed to overcome the disadvantages of virgin PPS, caused by a high coefficient of friction, and of glass-fiber reinforced PPS, which can cause premature wear of the counter face in movingpart applications. The combination of wear resistance, friction and fluid compatibility provides an improvement over conventional plastics such as PA and POM, but a more economical solution than higher-grade plastics such as PEEK. Contact: Quadrant Engineering Plastic Products, IP Noord – R. Tavernierlaan 2, B-8700 Tielt, Belgium. Tel: +32 51 423571, Fax: +32 51 423570, Email: [email protected]
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