From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Letter reporting the results of pressure tests conducted on Thermoflex bellows.
| Identifier | ExFiles\Box 151\2\ scan0228 | |
| Date | 19th April 1933 | |
| Telephone: SUNBURY, 406. Codes: BENTLEY'S, WESTERN UNION. Telegrams & Cables: PACKLESS, SUNBURY COMMON. THE PACKLESS GLAND CO., LTD. MAKERS OF THERMOFLEX DIRECTORS: M. {Mr Moon / Mr Moore} PAYNE. W. A. {Mr Adams} PAYNE. W. F. {Mr Friese} F. {Mr Friese} MARTIN-HURST. Bellows and Shaft Seals. THERMOFLEX WORKS. Windmill Road, Sunbury, Middlesex. W.M.H/GN: Your Ref: Experimental Dept: Hs {Lord Ernest Hives - Chair} /LES.1/BE: April 19th, 1933. Messrs. Rolls-Royce Limited, DERBY. Dear Sirs, With further reference to your letter of April 5th, we have now conducted careful tests to ascertain the maximum internal and external pressures which can safely be applied to our standard single wall Thermoflex 1 1/8" o {Mr Oldham} /d bellows. The result of these investigations shows that apart from a very slight set which takes place immediately pressure is applied, no perceptible change in the form of the bellows occurs until the pressure reaches 50 lbs/sq.in. As this is only slightly above the maximum safety pressure of 45 lbs/sq.in. mentioned in our letter of April 4th, and as reliability is obviously of paramount importance we would not recommend these bellows where the working pressure exceeds 30 lbs/sq.in. We have also made up a unit with a double wall bellows, and have tested it for distortion by applying external pressure. This bellows is stiffer than the single wall type, its spring rate being approximately 20 lbs. per 0.1" movement. The compression of the bellows was limited at 0.45", the free length of the bellows unit being 0.68". At 60 lbs/the bellows did not return to the free length of | ||