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 S.U. Company regarding pump diaphragm trouble caused by moisture absorption and fuel type.
| Identifier | ExFiles\Box 149\1\ scan0190 | |
| Date | 28th October 1935 | |
| x1263 S.U. CARBURETTER FLEXIBLE SILENT TELEPHONE No EAST 1171 (6 LINES) General Manager: T. C. SKINNER THE S.U. COMPANY. PROPRIETORS: MORRIS INDUSTRIES LTD East Works, Bordesley Green Road, Adderley Park-Birmingham,8. STATION:- ADDERLEY PARK, L.M.& S. RLY TELEGRAMS:- FLEXCARBUR, BIRMINGHAM. Your Ref. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}7/KW Our Ref. TCS/DR Oct. 28/35. W.A.Robotham Esq., Messrs. Rolls-Royce Ltd., DERBY. File Dear Mr. Robotham, I thank you for your letter of the 26th inst. regarding pump trouble in France, and I note the report of your tester. We have found, however, that the material originally used for the diaphragm absorbs moisture and expands under certain atmospheric conditions; and in this particular case I think the trouble in all probability is that when the diaphragms were originally fitted to the pump they had a certain amount of moisture in them, and had therefore expanded slightly, but the action of the petrol and heat under running conditions has dehydrated them and they have shrunk. I myself think the trouble is due to this rather than to the fabric being gummed up by the use of Esso fuel. I should advise further diaphragms of the same material to be fitted, but before doing so subject them to a temperature of 80° F.{Mr Friese} for twelve hours and see if the same trouble occurs after this has been done. Personally, I think it will put matters right. I am also arranging to let you have for test purposes, a dozen diaphragms made of what we term our No.3 Zinc fabric. Mr. Bowering has also had samples of this material, and it is absolutely unshrinkable under any normal condition whatever. It is, however, slightly soluble in alcohol, but so far, in spite of very severe tests we have made, this slight solubility has not caused a breakdown. I might add that we have | ||