14th I n t e r n a t i o n a l c o n f e r e n c e o n Fluid Sealing The 14th International c o n f e r e n c e o n Fluid Sealing was h e l d in Florence at t h e b e # n n l n g o f April. The c o n f e r e n c e was s p o n s o r e d and organised by the BHR Group Ltd, UK. It c o m p r i s e d t w o and h a l f days o f technical papers, k e y n o t e addresses and d i s c u s s i o n groups. A brief r e v i e w o f the c o n f e r e n c e and a list o f the presentations is given b e l o w .
The opening address of the conference was given by Brian Halligan, James Walker & Co Ltd, UK, in which he discussed the factors affecting the sealing industry's profit for this year. The main factors are seen to be legislation relating to manufacture and product use, environmental pressure and the growing awareness of leakage cost. The sealing industry has clearly recognised that end users are now actively measuring their costs as a function of loss of product. "Emissions are important, but for users cost is the most important factor", Barrie Kirkman, BP Chemicals. There is a greater expectation of seal performance and durability. This coupled with increased competition in the international marketplace, high labour rates and pressure on selling prices makes the seal manufacturer's job even more difficult. Companies have to continually find new technologies that meet the users' requirements, but the price of research and development is high. Mr Halligan went on to talk about ideas that could be addressed to help the sealing Industry progress and tackle the problems it faces; partnership sourcing, careful attention to what the customer needs and expects, standardisation, even the tribology of the seal face. The dissipation of temperature at the seal faces is crucial to ensure smooth operation of a seal. Worldwide, the seating industry seems to be actively dealing with the difficulties that face its customers;
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strategies are being formulated within individual companies and on a wider level in the formation of associations and working groups. The first workshop session was chaired by John Plumridge, EG & G Sealol Ltd and Neff Wallace, Flexibox Ltd. The workshop was entitled Fugitive Emissions. The principal causes of emission leakage have been identified as being the incorrect installation of equipment, inferior technology and budgetary contraints. In effect, this echoes the points made in Brian Halligan's opening address. Mr Plumridge and Mr Wallace presented information on studies that have been carried out in the USA, principally by the Chemical Manufacturers Assocition (CMA) and the Society of Tribologists and Lubrication Engineers (STLE). This served as a useful update for the largely European audience, although some of the information was covered in Sealing
Technology number 4. Barrie Kirkman, BP Chemicals then made a presentation [email protected]
BP's strategy to reduce its fugitive emissions to 3000 (in hydrocarbon losses) tormes by 1997 (see Sealing
Technology number 3). The major offenders, as identified by BP Chemicals on their plants, were valves, accountable for 75% of fugitive emissions. Other offenders were pump seals (10%), storage tank seals (10%) and flanges (5%). Reliable packing is vital for the smooth operation of valves on a plant, and guidelines for correct installation
of the packing was highlighted as one of the key points to successful valve stem sealing. As part of the strategy to reduce fugitive emissions from valves, BP Chemicals has decided to employ graphite technology. Mr Kirkman gave an example which put the problem in perspective. If a valve costs £100, then r e p a c k l ~ the valve once it has already been installed costs in the region of £1500. That factor of 15 makes it a costly business. The presentation was informative and important as it expressed an end users's view of the problem. It remains for other end users to carry out their own independent studies of emissions rates. As more data are collected, users and seal suppliers will have better information on which to base their solutions to emissions control problems. The second workshop session was chaired by Bob Flitney, BHR Group Ltd and Chris Forte, John Crane International and was entitled Me. chanical Seal Chambers. The Olx-ning question, from Chris Forte, was "what do users require from shaft sealing?" The answers, understandably, were low life cost, predictable performance and low levels of leakage. The discussion centred around research into seal arrangements and the ways in which a standards organisation can assist the seal user and the supplier, concentrating on the relationship between the seal and pump industries. The main conclusion reached was that seal chamber standards need to be revised to define clearly the boundaries between the pump and seal industrB, takln8 into account both Industries' needs and providin8 the flexibility to permit future technology changes for life cost improvements. The conference proceedings have been published by Mechanical Engineering Publications Ltd. A list of the papers presented at the conference, most of which exhibited a strong technical bias and came from seal manufacturers, is given overleaf. It would have been interestin8 to have a greater end user presence and comment throughout the conference. However, the conference was an excellent forum for discussion and no doubt has helped to form new partnerships and strategies to develop new technologies and increase prof-
Conference report itabflRy Papers presented: STATIC SEALS AND VALVES: The service envdope for biaxiany orientated reinforced PTFE sheet sealin8 materials, f R Hoyes, S Woolfenden, A D Stancliffe, TRA Sealing MaWrlals Ltd, UK Thermal transient sealing concepts - the "carrierring" spb~I wound gasket, G BrtSgs, S P Noble, Flexitallic Ltd, UK Experimental inv~tigation of leakage of static seals subjected to reciprocating vibration, F Rosengen, Chalmers Universify o f Technology, Swedeet Emission control packinu for high temperamre/htsh pressure valves and related devices, T Ueda, T Shiomi, K Ootawa, Nippon Pillar Packing Company Ltd, JaparL Stresses and deformation of compressed elastomeBc O.rtng seals, I Green, C English, Georgia Instituteo f Technology, US2t Finite dement analysis of bolted flange connections, V Wrisht, T & N Technology, f Hoyes, TBA Sealing Materials Ltd, G Briggs, Flexitallic Ltd, UK Up
R O T A R Y SEALS:
Eccentric seals for nuclear pomps, R Metcalfe, T A Graham, W C Wong, AECL Research, Canada Sealing of volatile liquids, f A M ton Houte de Lange, Flexibox BV, Netherlander
Evans, Flextbox Ltd, UK A shaft scaling sy~,,em with s u barrieI, A l Golubev, N V I ~ , Gidromash, Russi~ i0
This is a list of recently published patents covering designs and invertdons of relevance to S e a l i n g Tech ~ n o l o g y readers.
MECHANICAL SEALS II - a n a l y s i s / modelling: The accuracy of analytical solutions for the Countries can be identified by the temperature distribution in mechanical face code in front of the number: seals, 1 Ettson, M Groper, Technion, Israel OpOmt~ation and performance prediction of AT Austria US United States grooved face seals for gases and liquids, B BE Belgium AU Australia Tournerle, J Huitrlc, D Bonneau, J prene, CA Canada BR Brazil Universite de poitiers, France. CH Switzerland D Germany Thetmohydrodymanic calculation of end EP European Patent face seals, G Knoll, H Peeken, H- WHorl, Institut f u r Maschinenelemenfe Aachen ES Spain FR France Germany. H Finland HU Hungary Analysis of a hydrostatic gas seal with GB Britain IR FAre compliant face, R F Salant, Georgia Institute IL Israel JP Japan o f Technology, US& IT Italy LI Liechtenstein Modelling of plain face gas seal dynamics, S F KP North Korea NL Netherlands Leefe, BHR Group Ltd, UK LU Luxembourg RO Romania NO Norway SU Former Soviet SEALS m - techniUnion ques and experiments: SE Sweden W O World Patent Long term tests of mechanical seals for hot water applications, H-J Pranke, R Lacl~ Full copies of the original patent mayer, Technische Universitat Braunscl~ documents can be obtained from the weir, J Nosowicz, Feeder Burgmann following: Dictungswerke GmbH & Co, Germany OpttmL~ation of the pumping ring in a mechanical seal with an integrated cooler for The British Library Patent Ex. feed water pomps, D Buchdahl, EDF/DER, press, R Martin, E D F / $ ~ , G Gueret, Larry 25 S o u t h a m p t o n Buildings Inwrna~onal, M Blanc, GEC Alsthom London WC2A lAW, UK Bergeron Rateau, France. Fax: 071 323 7230
Sealin8 techniques for subsea control appliImpact tests of rubber materials for seals, F cations, M C Theobald, YSSL Lid, UK Hirano, H Miyasawa, K Imado, Oita Seal failure in fluid power applications University, Y gawahara, NOK Corporacauses and appearances, H Weiss, Busak tion, Japan, and Shamban GmbH & Co, Germany. Se~iinS liquid with alg, N Stan~q~r,WHaas, H Hydganfic rod seals with laser-structures K Mdller, Unit~rsttat Stuttsart, Germany. back-surface, U Fmnzel, H K Muller, Finite element-amly~ of PTFE-shaft-se~ G Universitat, Germany Wustenhagen, H K MuHer, K-D Meek, Effects of surface finish on reciprocating seal Untversttat StuUga~, Germany performance, R K Plimey, B S Nau, BHR Group Ltd, UK MECHANICAL SEALS I - p r a c t i c a l : The effects of multistage contact pressure Trends in mechanical seal performance at distr~ution on sealing and ~'k~onzl cha~three process plants in the oil llxlust.,7, P A actertsitics in reciprocating seals, YKanzaConner, Conoco, M T Thew, University o f kt, Y Kawahara, NOK Co¢,poration, M Southampton, UK Kaneta, Kyushu Institute o f TechnoloSy, Seal check with double seal leaking, J A M Japan. ten HouSe de Lange, Flexibox BV, NetherStudy of the behaviour of an hydraulic landL accumulator seal, G Morin, S DelaUre, Knife edge mechanical seal for low emission Princpta Recherd~ Developpment SA, of hJgh Wmc(~tyflukl& YGom, g o h b a , France. Nippon Pillar Packings Co Ltd, Japaft New deveiopemnts in bellow seals for For further information, contact:
improvedperfoemnce and retm,mty,J a
(The British Library will also supply a list of UK libraries included in the Patent Information Network.) US Preterit O f f i c e Scientific Library 1 5 t h a n d East S t r e e t s , NW W a s h i n g t o n , DC 20231, USA
The J a p a a e s e Patent Oftice 43 K a l m u m i g a ~ l d 3 ~ h o m e
Chlyoda-ku, Tokyo 100, Japan
BELR G r o u p Ltd, C r a n f l e l d , B e d f o r d , MK43 0AJ, UK. Tel: + 44 234 750 422; Fax: + 44 234 750 074.
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