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 from The British Thermostat Co. regarding a water hammer issue caused by a bellows and valve area mismatch.
| Identifier | ExFiles\Box 156\2\ scan0074 | |
| Date | 23th April 1938 | |
| Telephone: SUNBURY-ON-THAMES 456 (6 LINES) Telegrams & Cables: THERMOSTAT, SUNBURY-ON-THAMES. Code: BENTLEY'S 1328 . THE BRITISH THERMOSTAT CO., LTD. Makers of Scientific Instruments. TEDDINGTON WORKS. Windmill Road, Sunbury-on-Thames, Middlesex. FBI (FEDERATION OF BRITISH INDUSTRIES) INCORPORATED BY ROYAL CHARTER JB LTD REGISTERED TRADE MARK MEMBERS OF THE NATIONAL UNION OF MANUFACTURERS (NMU) DIRECTORS: COL. N. HUDSON, J.{Mr Johnson W.M.} E.{Mr Elliott - Chief Engineer} SHERLOCK } MANAGING. W. F.{Mr Friese} F.{Mr Friese} MARTIN-HURST L. S. SWINNERTON DYER, F.{Mr Friese} G.{Mr Griffiths - Chief Accountant / Mr Gnapp} POPLETT. Your Ref: Rm{William Robotham - Chief Engineer}/Std.7/MH{M. Huckerby}: WMH/GN: April 23rd, 1938. Messrs. Rolls-Royce Ltd. DERBY. Dear Sirs, For the attention of Mr.C.S. Steadman. We thank you for your letter dated April 22nd. From your observations and examination of the drawings it seems probable that the water hammer is being caused by the use of a bellows, the mean area of which is greater than the mean area of the valve through the radiator. The mean area of a 1 3/4" bellows is approximately 1.8 sq. inches, and the area of your thermostat seating appears to be approximately 1.05 sq.ins. We have not yet had an opportunity of pressure testing the unit which we have here, but it seems to us that the answer can be more quickly obtained if you will machine out the diameter of the valve seating in the unit to which you have fitted the celluloid window, so as to bring about a condition of balance. Alternatively, we can make up a unit for you immediately, fitted with smaller bellows so as to render an alteration to your parts unnecessary. If you would like us to do this will you please telephone the writer on Monday morning? Yours truly, THE BRITISH THERMOSTAT CO.LTD. W.Martin-Hurst. Director. | ||