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. Ltd. detailing the operation of a thermostatically operated car header tank relief valve.
| Identifier | ExFiles\Box 156\2\ scan0231 | |
| Date | 31th May 1939 | |
| [Handwritten] 1328 Telephone: SUNBURY-ON-THAMES 456 (7 LINES) Telegrams & Cables: THERMOSTAT, SUNBURY-ON-THAMES. Code: BENTLEY'S THE BRITISH THERMOSTAT CO., LTD. Makers of Scientific Instruments. DIRECTORS: COL. N. HUDSON. J.{Mr Johnson W.M.} E.{Mr Elliott - Chief Engineer} SHERLOCK } MANAGING. W. F.{Mr Friese} P. MARTIN HURST } F.{Mr Friese} G.{Mr Griffiths - Chief Accountant / Mr Gnapp} POPLETT. F.{Mr Friese} PARMENTER. TEDDINGTON WORKS. Windmill Road. Sunbury-on-Thames. Middlesex. ON A.I.D. AIR MINISTRY APPROVED LIST. Our Ref. KMP/OH. Rolls-Royce, Ltd., Derby. 31st May 1939. Dear Sirs, For the attention of Mr. Edwards. As requested over the telephone this afternoon we send you herewith a further print of our drawing FAB/A/1 shewing the thermostatically operated car header tank relief valve. The operation of this instrument is :- At approximately 100°C the bellows "A", to the bottom of which is attached the valve seat and bellows stop, expands downwards until the valve hits the seat. In this position the bellows stop is just clear of the bellows top plate. The main spring is set such that a pressure of 15 lb. per square inch will cause it to collapse, thus, as the temperature rises above 100°C, <s>below</s> the pressure inside the bellows is sufficient to start collapsing the spring, the bellows top plate will come up against the bellows stop, and after this has happened no further expansion of the bellows can take place, and the whole instrument will, therefore, act as a plain spring operated relief valve. [handwritten] inside the header tank We trust that we have made ourselves clear, and shall be pleased to give you any further information. Yours faithfully, THE BRITISH THERMOSTAT CO., LTD., [Signature] K.{Mr Kilner} M.{Mr Moon / Mr Moore} Petter. | ||