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 Messrs. Hepworth & Grandage Ltd. regarding a discrepancy in wall pressure calculations for a valve ring.
| Identifier | ExFiles\Box 148\3\ scan0263 | |
| Date | 8th September 1937 | |
| 180/ Rm{William Robotham - Chief Engineer}/Mths.{Reg Matthews}7/WH. 8th. September 1937. Messrs. Hepworth & Grandage Ltd., St.{Capt. P. R. Strong} John's Works, Bradford, Yorks. For the attention of Mr. N.C.Brearley. Dear Sirs, With reference to your letter of yesterday, I have been through my calculations again, and using an E N valve of 15 x 10^6 I find that the wall pressure is 18lbs./sq.inch. With the E N valve you use I find that the pressure would be in the region of 23-24lbs/sq. inch, so that the only thing I can suggest is that you have made some mistake in calculating. The normal British proportion of D/29 gives a wall pressure of 9 - 13lbs/sq. inch but our proposed ring is .134 radial thickness or D/26 (approx.) and we should therefore, get an appreciably higher wall pressure. We have also received some similar rings from another firm made to the exact dimensions given to you and they average 17.8lbs/sq. inch. Will you please check over your calculations and make certain that there is no mistake before we decide further on what proceedure to take, I am sure somebody must have tripped up somewhere. Yours faithfully, for ROLLS-ROYCE LTD. | ||