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Gas-permeable cover seal cuts assembly and production costs
sealing
TECHNOLOGY
ISSN 1350-4789 July 2011
www.sealingtechnology.info
Gas-permeable cover seal cuts assembly and production costs
F
reudenberg Simrit GmbH & Co Kg has developed a breathable sealing cap which, it claims, has the potential to cut assembly and production costs for machine and gear manufacturers. Assembly bore holes and other bore holes in machinery and industrial gears are generally closed and sealed using inexpensive caps. When these aggregates, and the lubricants inside them, heat up during operation, the rise in pressure can be significant – up to 0.5 bar (50 kPa). This rise in pressure puts a strain on the shaft seal by pressing it onto the shaft, causing increased wear and reducing the service life of the seal. Under unfavourable conditions this rise in pressure can even cause the seal or the sealing cap to move out of position. This is certainly not a new problem and can be solved by installing vent valves. However, this approach involves drilling additional bore holes, cutting threads and mounting valves. The firm says that by integrating vent and ventilation functions as a gas-permeable cover seal directly into a sealing cap, it has succeeded in making the most of potential savings in machines where heat occurs.
The only prerequisite is that the sealing cap has to be positioned appropriately and only flooded half way. In order to ensure automatic pressure equalisation, very small bore holes are drilled in standard sealing caps. These microscopic openings are then closed using a specially treated non-woven. This material is both air-permeable, and water-impermeable and oil-impermeable. In this way, the non-woven equalises the pressure. This enables gears to be operate at ambient pressure even if the temperature fluctuates considerably – from well below 0°C up to approximately 120°C (and up to 150°C for brief intervals). Simrit says that other components will be equipped with this basic technology. In the foreseeable future this vent and ventilation functionality will be integrated into other machine elements such as bellows or Simmerrings. Contact: Freudenberg Simrit GmbH & Co Kg, Simrit Marketing Europe, D-69465 Weinheim, Germany. Tel: +49 1805 746748, Fax: +49 1803 746748, Email: [email protected], Web: www.simrit.de
Contents Contents
News Gas-permeable cover seal cuts assembly and production costs
1
Gasket material is designed for high-temperature sealing applications
2
Hydrablock carries out localised pressure testing of pipework
2
Dual-layer enhancement for seals reduces friction
3
Viton Extreme seals are resistant to chemicals with a high pH
3
Perfluoroelastomers improve uptime in demanding semiconductor production processes
4
Simrit improves surface-finish testing methodology to increase seal performance
4
Concerns grow over fluorspar shortage
5
Eriks develops anti-microbial rubber technology
Company News Flexitallic appoints allied distributors in Norway and Thailand
6
Dow Corning opens applications development centre in Korea
6
Vertellus establishes research centre in New Jersey
6
Conferences and Meetings News IMechE seminar covers operational reliability of reciprocating compressors 7
Features Features review – another year of variety
Regulars Bob’s Bit
8–12
3
In Brief
5, 7
Patents
13
Events Calendar
16
Simrit’s breathable sealing caps have the potential to help machine and gear manufacturers reduce assembly and production costs.
ISSN 1350-4789/11 1350-4789/10 © 2011 Elsevier Ltd. All rights reserved. This journal and the individual contributions contained in it are protected under copyright by Elsevier Ltd, and the following terms and conditions apply to their use: Photocopying Single photocopies of single articles may be made for personal use as allowed by national copyright laws. Permission of the publisher and payment of a fee is required for all other photocopying, including multiple or systematic copying, copying for advertising or promotional purposes, resale, and all forms of document delivery. Special rates are available for educational institutions that wish to make photocopies for non-profit educational classroom use.
TECHNOLOGY
ISSN 1350-4789 July 2011
www.sealingtechnology.info
Gas-permeable cover seal cuts assembly and production costs
F
reudenberg Simrit GmbH & Co Kg has developed a breathable sealing cap which, it claims, has the potential to cut assembly and production costs for machine and gear manufacturers. Assembly bore holes and other bore holes in machinery and industrial gears are generally closed and sealed using inexpensive caps. When these aggregates, and the lubricants inside them, heat up during operation, the rise in pressure can be significant – up to 0.5 bar (50 kPa). This rise in pressure puts a strain on the shaft seal by pressing it onto the shaft, causing increased wear and reducing the service life of the seal. Under unfavourable conditions this rise in pressure can even cause the seal or the sealing cap to move out of position. This is certainly not a new problem and can be solved by installing vent valves. However, this approach involves drilling additional bore holes, cutting threads and mounting valves. The firm says that by integrating vent and ventilation functions as a gas-permeable cover seal directly into a sealing cap, it has succeeded in making the most of potential savings in machines where heat occurs.
The only prerequisite is that the sealing cap has to be positioned appropriately and only flooded half way. In order to ensure automatic pressure equalisation, very small bore holes are drilled in standard sealing caps. These microscopic openings are then closed using a specially treated non-woven. This material is both air-permeable, and water-impermeable and oil-impermeable. In this way, the non-woven equalises the pressure. This enables gears to be operate at ambient pressure even if the temperature fluctuates considerably – from well below 0°C up to approximately 120°C (and up to 150°C for brief intervals). Simrit says that other components will be equipped with this basic technology. In the foreseeable future this vent and ventilation functionality will be integrated into other machine elements such as bellows or Simmerrings. Contact: Freudenberg Simrit GmbH & Co Kg, Simrit Marketing Europe, D-69465 Weinheim, Germany. Tel: +49 1805 746748, Fax: +49 1803 746748, Email: [email protected], Web: www.simrit.de
Contents Contents
News Gas-permeable cover seal cuts assembly and production costs
1
Gasket material is designed for high-temperature sealing applications
2
Hydrablock carries out localised pressure testing of pipework
2
Dual-layer enhancement for seals reduces friction
3
Viton Extreme seals are resistant to chemicals with a high pH
3
Perfluoroelastomers improve uptime in demanding semiconductor production processes
4
Simrit improves surface-finish testing methodology to increase seal performance
4
Concerns grow over fluorspar shortage
5
Eriks develops anti-microbial rubber technology
Company News Flexitallic appoints allied distributors in Norway and Thailand
6
Dow Corning opens applications development centre in Korea
6
Vertellus establishes research centre in New Jersey
6
Conferences and Meetings News IMechE seminar covers operational reliability of reciprocating compressors 7
Features Features review – another year of variety
Regulars Bob’s Bit
8–12
3
In Brief
5, 7
Patents
13
Events Calendar
16
Simrit’s breathable sealing caps have the potential to help machine and gear manufacturers reduce assembly and production costs.
ISSN 1350-4789/11 1350-4789/10 © 2011 Elsevier Ltd. All rights reserved. This journal and the individual contributions contained in it are protected under copyright by Elsevier Ltd, and the following terms and conditions apply to their use: Photocopying Single photocopies of single articles may be made for personal use as allowed by national copyright laws. Permission of the publisher and payment of a fee is required for all other photocopying, including multiple or systematic copying, copying for advertising or promotional purposes, resale, and all forms of document delivery. Special rates are available for educational institutions that wish to make photocopies for non-profit educational classroom use.