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 to The British Thermostat Co. Ltd. regarding test results of an unbalanced thermostat and requesting information on alternatives.
| Identifier | ExFiles\Box 156\1\ scan0171 | |
| Date | 19th April 1937 | |
| 1328. 19th April 1937 Rm{William Robotham - Chief Engineer}/Std.13/AP. The British Thermostat Co.Ltd., Teddington Works, Windmill Road, Sunbury-on-Thames, MIDDLESEX. For the attention of Mr.Martin-Hurst. Dear Sirs, We have now tested out the thermostats which you sent us in the modified thermostat casing which we showed you, on a car. The thermostats were operated with a by-pass pipe continually open - in every case the average running water temperature on the road was approximately 8 - 10°C. below the opening temperature of the thermostat as given by yourselves on the labels attached to the thermostats. Assuming that the opening temperatures of the thermostats were accurately determined by you, this indicates that the valve and bellows are unbalanced and are being affected by water pressure. We should like to know whether you can correct this un-balance, if not it looks as if we shall have to use the double acting type of valve as shown on your drawing B.G.A.3357.A. During warming up with the thermostats mentioned above, pressures up to 18 lbs/sq.in. were noted under the valve and the valve opened approximately 10°C below its correct figure. We should like the following information from you:- 1. Can you supply us with a thermostat of the type which we have already had (Vauxhall model) but correctly balanced for water pressure. 2. Can you supply us with a thermostat as drawing B.G.A.3357.A. but having a by-pass area of approximately .220 sq.in. - if so what is its production price likely to be.? 3. A second print of B.G.A.3357.A. continued | ||