Torvac now offers comprehensive furnace capability

Vacuum News At the Virgin Megastore, the Spectron was uncrated, run up and then connected into the roughing line of the coating system. A particular advantage of the Spectron in such applications is its ability to find both large and very small leaks and to rough pump the complete chamber using its own vacuum pumping system. Initially, the Spectron was used to investigate the suspect air piston since it had been established that the leakage coincided with its operation. However, it became clear that, although this was indeed the case, the air piston itself was performing satisfactorily. Further investigation soon revealed, however, that operation of the piston was causing flexure of a weld in the main chamber of the coating system and that a hair line crack had developed which was opening the chamber to atmosphere each time the piston operated. According to Keith Grover, the total time to detect the leak, was about 1 h, the larger part of which was taken up investigating the ultimately blameless air piston. "Without the Spectron, we could have still been looking for the leak at Christmast' he commented. Having witnessed the speed and facility with which the Spectron 3000S was able to locate leaks in the coating system, it was hardly surprising that, when a similar problem arose, Grover again contacted Bewhay. Again they were able to make the Spectron available and Edwards" Steve Fraser was summoned from his sickbed to instruct Keith Grover and his team in its operation. The leak detector was then left with Virgin over a weekend during which the problem was rapidly isolated and corrected, allowing the CD facility to resume production on the following Monday morning. For further information please contact :

A Spectron 3000S leak detector manufactured by Edwards High Vacuum International recently found itseff in a starring role at the Virgin Megastore in London's Oxford Street. By rapidly locating a large leak in the compact disk (CD) production system at the store, the Spectron enabled Virgin to restart production of CDs which are sold in the Megastore and through other Virgin outlets. microscopic layer of aluminium which is deposited in a vacuum chamber. In order to ensure the integrity of the deposition process, ancillary equipment detects the presence of impurities in the vacuum chamber and will automatically shut down the system should they reach a critical level. This is most likely to result from a leak from atmosphere into the chamber carrying moisture into the system. According to Keith Grover, Compact Disk Factory Manager at the Oxford Street Store, leaks do occasionally occur in the air operated pistons which manipulate batches of disks in the coating system. Should a leak cause the system to shut down, it has been possible to detect by inspection which air piston is causing the problem and renew its seals. This entire process can take between 6 and 8 h and, if unscheduled, can cause a major interruption of production. When a major leak caused Virgin's coater to shut down earlier last Summer, Keith Grover naturally assumed that it was caused by a faulty air piston. He and his team therefore proceeded to renew the seals on the suspect air piston and, when this failed to cure the problem, to replace the piston itself. When even this failed, and with the system having now been "down' for some 6 days, Grover contacted D Bewhay (Vacuum & Technical) Ltd, the Borehamwood, Herts based suppliers of vacuum equipment. Bewhay, w h o are stockists of the Edwards" Spectron leak detector range immediately responded by supplying a Spectron 3000S Leak Detector and contacted Edwards who despatched Product Support Specialist Steve Fraser to Oxford Street to advise on its operation. 1016

Mr J F Fowler Edwards High Vacuum International Manor Royal, Crawley, West Sussex RH10 2LW Tel (national) 0293 28844 (international) +44 293 28844

Torvac n o w offers c o m p r e h e n s i v e f u r n a c e c a p a b i l i t y Torvac Furnaces Ltd has acquired the full UK marketing rights for the products of Vacuum Industries Inc (VI), based in Massachusetts USA. The VI agreement follows a similar deal with Centorr Associates based in New Hampshire and gives Torvac Furnaces the ability to manufacture, market and maintain a complete spectrum of furnace products under three brand names--Torvac, VI and Centorr. These brands embrace all aspects of vacuum and atmosphere thermal processing--from laboratory to heavy industry requirements. Vl's furnaces provide unusual flexibility of operation and range from the System 7 laboratory furnaces to equipment for handling ten-tonne batches of nickel alloy components as much as 30 m (97 ft) long. Well known outside the USA are Vl's hard metal sintering furnaces which feature special Sweepgas Systems for binder and lubricant removal. The company also produces a full range of hot press and vacuum melting equipment. The Torvac brand, based on the company's original designs, includes furnaces for brazing and heat treatment at very high vacuum--and with pressure gas quenching facilities. Top+loaded molybdenum heated furnaces are generally in the small and medium size categories, operating at temperatures up to 1600°C. A second series of multiprocess furnaces are characterised by horizontally loaded, double walled vessels housing graphitic hot zones operating in the range 200-20000C and 10-6-3000 mbar. Centorr brand equipment has been at the forefront of advanced materials research and development for nearly 30 years. Most designs