- Email: [email protected]
Thames Barrier seals are replaced after 20 years of service
NEWS
Editorial Office: Elsevier Ltd The Boulevard, Langford Lane Kidlington, Oxford OX5 1GB, UK Fax: +44 (0)1865 843973 Web: www.sealingtechnology.info Publisher: Laurence Zipson E-mail: [email protected] Editor: Bob Flitney Tel: +44 (0)1799 501659 Email: [email protected] Production Support Manager: Lin Lucas E-mail: [email protected] Editorial advisory board: 9VES "IREMBAUT & s #YRIL 8 ,ATTY & !MRAT 0ARMAR 5+ s 2ICHARD & 3ALANT 53! 7OLFGANG 3CHÚPPLEIN $ s 3HUZO 3EYA * 3COTT 3VENDSEN 53!
Subscription Information An annual subscription to Sealing Technology includes 12 printed issues and online access for up to 5 users. Prices: 1112 for all European countries & Iran US$1247 for all countries except Europe and Japan ¥147 800 for Japan (Prices valid until 31 December 2009) To subscribe send payment to the address above. Tel: +44 (0)1865 843687/Fax: +44 (0)1865 834971 Email: [email protected], or via www.sealingtechnology.info. Subscriptions run for 12 months, from the date payment is received. Periodicals postage is paid at Rahway, NJ 07065, USA. Postmaster send all USA address corrections to: Sealing Technology, 365 Blair Road, Avenel, NJ 07001, USA Permissions may be sought directly from Elsevier Global Rights Department, PO Box 800, Oxford OX5 1DX, UK; phone: +44 1865 843830, fax: +44 1865 853333, email: [email protected]. You may also contact Global Rights directly through Elsevier’s home page (www.elsevier.com), selecting first ‘Support & contact’, then ‘Copyright & permission’. In the USA, users may clear permissions and make payments through the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, USA; phone: +1 978 750 8400, fax: +1 978 750 4744, and in the UK through the Copyright Licensing Agency Rapid Clearance Service (CLARCS), 90 Tottenham Court Road, London W1P 0LP, UK; phone: +44 (0)20 7631 5555; fax: +44 (0)20 7631 5500. Other countries may have a local reprographic rights agency for payments. Derivative Works Subscribers may reproduce tables of contents or prepare lists of articles including abstracts for internal circulation within their institutions. Permission of the Publisher is required for resale or distribution outside the institution. Permission of the Publisher is required for all other derivative works, including compilations and translations. Electronic Storage or Usage Permission of the Publisher is required to store or use electronically any material contained in this journal, including any article or part of an article. Except as outlined above, no part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior written permission of the Publisher. Address permissions requests to: Elsevier Science Global Rights Department, at the mail, fax and email addresses noted above. Notice No responsibility is assumed by the Publisher for any injury and/ or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. Because of rapid advances in the medical sciences, in particular, independent verification of diagnoses and drug dosages should be made. Although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer.
02129 Pre-press/Printed by Mayfield Press (Oxford) Ltd
2
Sealing Technology
Thames Barrier seals are replaced after 20 years of service
S
eals that are part of the hydraulic system which opens and closes the Thames Barrier’s gates are being replaced. Absolute reliability is needed from the hydraulic cylinders that lift the barrier’s massive gates which protect London against surge tides or flooding. ‘For over 20 years the same 16 sets of James Walker hydraulic seals have worked in the heat of summer and freezing winter conditions to open and close the barrier’s four main 3300tonne gates,’ commented Murray Crozier, regional sales executive for James Walker. ‘These seals are now being replaced as part of the cylinder refurbishment project.’ Each cylinder uses a Solosele G single element seal with a block ring, and a Twinset packing set, all of 1.1-m diameter, plus a Chevron multi-lip packing set, 431 mm in diameter. Used seals from the barrier have been examined by James Walker Technology Centre to determine their condition. All were found to be within the customer’s original tolerance limits, and in good working order. There was little evidence of wear or damage to the seals, apart from slight scoring on the lip of a Solosele G and some minute specks of metal imprinted on its circumference. Andy Parkinson, James Walker’s business development manager for heavy-duty hydraulics, explained: ‘These are the worst possible working conditions for hydraulic seals. They sit in the same position during long periods of inactivity, then they must work faultlessly when needed.’
Contact: James Walker & Co Ltd, Customer Support Centre, 1 Millennium Gate, Westmere Drive, Crewe, Cheshire CW1 6AY, UK. Tel: +44 1270 536000, Fax: +44 1270 536100, Email: [email protected], Web: www.jameswalker.biz.
Research shows that traditional fillers outperform nano-particles
R
esearch conducted by Trelleborg Sealing Solutions has shown that the traditional fillers, used in the majority of its Turcon polytetrafluor-
oethylene-based sealing materials as additives to improve wear reduction, outperform nano-particles as additives. Industry is currently excited about the use of nano-particles as fillers for polytetrafluoroethylene-based sealing materials to enhance seal performance. Responding to this, Trelleborg Sealing Solutions researched and compared the wear-reducing ability of its traditional additives with that of nano-particles. In these tests the optimised Turcon additives outperformed the nano-particles, says the firm. ‘Despite the results which show that our traditional additives outperform nano-particles, Trelleborg Sealing Solutions will continue to work on sealing nanotechnology,’ said Thomas Larsen, who led the test programme at Trelleborg Sealing Solutions. ‘Our Turcon compounds are optimised for service conditions using traditional fillers and are generally difficult to beat. Even so, we will continue to investigate if improvements can be made using nano-particles.’ Trelleborg Sealing Solutions tested polytetrafluoroethylene (PTFE) filled with the following nano-particles: carbon nano-tubes (MWCNT), alpha aluminium oxide (Al2O3, alpha), beta aluminium oxide (Al2O3, beta), tin oxide (SnO2), copper oxide (CuO), zinc oxide (ZnO) and iron oxide (Fe2O33) – in all cases at 1wt%. The performance was compared with both virgin PTFE and Turcon T05. The results demonstrate that different types of nano-particles have different effects on the wear resistance of PTFE – going from virtually no effect to wear reductions beyond a factor of 50. For some, nano-particles performance was dependent on whether the systems were running dry or lubricated. For instance, MWCNT performed very well when dry-running, but poor in lubricated conditions, while others, such as Al2O3 alpha, gave good overall performance. However, none of the materials filled with nano-particle were capable of out-performing the wear resistance of Turcon T05, dry-running or lubricated. Virgin PTFE has very low wear resistance and fillers are added to the material to increase its wear resistance in dynamic sealing applications. Nano-particles, which have at least one dimension in the size range of 1–100 nm, offer an alternative to traditional fillers. These are currently receiving much attention as fillers for polymers and are promoted as improving mechanical and tribological properties at a low degree of fill, as well as reducing the risk of abrasive action against mating counter surfaces. Contact: Trelleborg Sealing Solutions, Global Marketing & Communications, Handwerkstrasse 5–7, D-70565 Stuttgart, Germany. Tel: +49 711 78640, Fax: +49 711
December 2009
Editorial Office: Elsevier Ltd The Boulevard, Langford Lane Kidlington, Oxford OX5 1GB, UK Fax: +44 (0)1865 843973 Web: www.sealingtechnology.info Publisher: Laurence Zipson E-mail: [email protected] Editor: Bob Flitney Tel: +44 (0)1799 501659 Email: [email protected] Production Support Manager: Lin Lucas E-mail: [email protected] Editorial advisory board: 9VES "IREMBAUT & s #YRIL 8 ,ATTY & !MRAT 0ARMAR 5+ s 2ICHARD & 3ALANT 53! 7OLFGANG 3CHÚPPLEIN $ s 3HUZO 3EYA * 3COTT 3VENDSEN 53!
Subscription Information An annual subscription to Sealing Technology includes 12 printed issues and online access for up to 5 users. Prices: 1112 for all European countries & Iran US$1247 for all countries except Europe and Japan ¥147 800 for Japan (Prices valid until 31 December 2009) To subscribe send payment to the address above. Tel: +44 (0)1865 843687/Fax: +44 (0)1865 834971 Email: [email protected], or via www.sealingtechnology.info. Subscriptions run for 12 months, from the date payment is received. Periodicals postage is paid at Rahway, NJ 07065, USA. Postmaster send all USA address corrections to: Sealing Technology, 365 Blair Road, Avenel, NJ 07001, USA Permissions may be sought directly from Elsevier Global Rights Department, PO Box 800, Oxford OX5 1DX, UK; phone: +44 1865 843830, fax: +44 1865 853333, email: [email protected]. You may also contact Global Rights directly through Elsevier’s home page (www.elsevier.com), selecting first ‘Support & contact’, then ‘Copyright & permission’. In the USA, users may clear permissions and make payments through the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, USA; phone: +1 978 750 8400, fax: +1 978 750 4744, and in the UK through the Copyright Licensing Agency Rapid Clearance Service (CLARCS), 90 Tottenham Court Road, London W1P 0LP, UK; phone: +44 (0)20 7631 5555; fax: +44 (0)20 7631 5500. Other countries may have a local reprographic rights agency for payments. Derivative Works Subscribers may reproduce tables of contents or prepare lists of articles including abstracts for internal circulation within their institutions. Permission of the Publisher is required for resale or distribution outside the institution. Permission of the Publisher is required for all other derivative works, including compilations and translations. Electronic Storage or Usage Permission of the Publisher is required to store or use electronically any material contained in this journal, including any article or part of an article. Except as outlined above, no part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior written permission of the Publisher. Address permissions requests to: Elsevier Science Global Rights Department, at the mail, fax and email addresses noted above. Notice No responsibility is assumed by the Publisher for any injury and/ or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. Because of rapid advances in the medical sciences, in particular, independent verification of diagnoses and drug dosages should be made. Although all advertising material is expected to conform to ethical (medical) standards, inclusion in this publication does not constitute a guarantee or endorsement of the quality or value of such product or of the claims made of it by its manufacturer.
02129 Pre-press/Printed by Mayfield Press (Oxford) Ltd
2
Sealing Technology
Thames Barrier seals are replaced after 20 years of service
S
eals that are part of the hydraulic system which opens and closes the Thames Barrier’s gates are being replaced. Absolute reliability is needed from the hydraulic cylinders that lift the barrier’s massive gates which protect London against surge tides or flooding. ‘For over 20 years the same 16 sets of James Walker hydraulic seals have worked in the heat of summer and freezing winter conditions to open and close the barrier’s four main 3300tonne gates,’ commented Murray Crozier, regional sales executive for James Walker. ‘These seals are now being replaced as part of the cylinder refurbishment project.’ Each cylinder uses a Solosele G single element seal with a block ring, and a Twinset packing set, all of 1.1-m diameter, plus a Chevron multi-lip packing set, 431 mm in diameter. Used seals from the barrier have been examined by James Walker Technology Centre to determine their condition. All were found to be within the customer’s original tolerance limits, and in good working order. There was little evidence of wear or damage to the seals, apart from slight scoring on the lip of a Solosele G and some minute specks of metal imprinted on its circumference. Andy Parkinson, James Walker’s business development manager for heavy-duty hydraulics, explained: ‘These are the worst possible working conditions for hydraulic seals. They sit in the same position during long periods of inactivity, then they must work faultlessly when needed.’
Contact: James Walker & Co Ltd, Customer Support Centre, 1 Millennium Gate, Westmere Drive, Crewe, Cheshire CW1 6AY, UK. Tel: +44 1270 536000, Fax: +44 1270 536100, Email: [email protected], Web: www.jameswalker.biz.
Research shows that traditional fillers outperform nano-particles
R
esearch conducted by Trelleborg Sealing Solutions has shown that the traditional fillers, used in the majority of its Turcon polytetrafluor-
oethylene-based sealing materials as additives to improve wear reduction, outperform nano-particles as additives. Industry is currently excited about the use of nano-particles as fillers for polytetrafluoroethylene-based sealing materials to enhance seal performance. Responding to this, Trelleborg Sealing Solutions researched and compared the wear-reducing ability of its traditional additives with that of nano-particles. In these tests the optimised Turcon additives outperformed the nano-particles, says the firm. ‘Despite the results which show that our traditional additives outperform nano-particles, Trelleborg Sealing Solutions will continue to work on sealing nanotechnology,’ said Thomas Larsen, who led the test programme at Trelleborg Sealing Solutions. ‘Our Turcon compounds are optimised for service conditions using traditional fillers and are generally difficult to beat. Even so, we will continue to investigate if improvements can be made using nano-particles.’ Trelleborg Sealing Solutions tested polytetrafluoroethylene (PTFE) filled with the following nano-particles: carbon nano-tubes (MWCNT), alpha aluminium oxide (Al2O3, alpha), beta aluminium oxide (Al2O3, beta), tin oxide (SnO2), copper oxide (CuO), zinc oxide (ZnO) and iron oxide (Fe2O33) – in all cases at 1wt%. The performance was compared with both virgin PTFE and Turcon T05. The results demonstrate that different types of nano-particles have different effects on the wear resistance of PTFE – going from virtually no effect to wear reductions beyond a factor of 50. For some, nano-particles performance was dependent on whether the systems were running dry or lubricated. For instance, MWCNT performed very well when dry-running, but poor in lubricated conditions, while others, such as Al2O3 alpha, gave good overall performance. However, none of the materials filled with nano-particle were capable of out-performing the wear resistance of Turcon T05, dry-running or lubricated. Virgin PTFE has very low wear resistance and fillers are added to the material to increase its wear resistance in dynamic sealing applications. Nano-particles, which have at least one dimension in the size range of 1–100 nm, offer an alternative to traditional fillers. These are currently receiving much attention as fillers for polymers and are promoted as improving mechanical and tribological properties at a low degree of fill, as well as reducing the risk of abrasive action against mating counter surfaces. Contact: Trelleborg Sealing Solutions, Global Marketing & Communications, Handwerkstrasse 5–7, D-70565 Stuttgart, Germany. Tel: +49 711 78640, Fax: +49 711
December 2009