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 Negretti & Zambra regarding the condition and reading discrepancies of a returned Acrometer valve.
| Identifier | ExFiles\Box 40\1\ Scan082 | |
| Date | 19th September 1924 | |
| 43695 NEGRETTI & ZAMBRA, OPTICIANS and SCIENTIFIC INSTRUMENT MAKERS. HEAD OFFICE: 38, HOLBORN VIADUCT, E.C.1. BRANCHES: 5, LEADENHALL ST.{Capt. P. R. Strong}, E.C.3. 122, REGENT ST.{Capt. P. R. Strong}, W.1. FACTORY: HALF MOON WORKS, BARNSBURY, N.1. OVERSEAS BRANCHES: BRUSSELS. OTTAWA. TORONTO. VANCOUVER FOUNDED 1850. HIGHEST AWARDS AT THE INTERNATIONAL EXHIBITIONS OF LONDON 1851. LONDON 1862. PARIS 1878. PARIS 1900. BRUSSELS 1910. TURIN 1911. GHENT. 1913. CABLE: NEGRETTI, LONDON. TELEGRAPHIC ADDRESS: NEGRETTI, CENT, LONDON. TELEPHONE: HOLBORN 960. (TWO LINES) [STAMP] PLEASE QUOTE REF: GAUGE DEPT. 38, HOLBORN VIADUCT, LONDON, E.C.1 Sept. 19th 1924. Messrs Rolls-Royce Ltd., Nightingale Road, DERBY. Dear Sirs, Your Ref. Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}1/L.G. Since we wrote you on the 17th inst., we have duly received the Acrometer non return valve and the little release valve belonging to this instrument. We have examined these carefully, and as far as we can see they are in perfect condition, and return them today. With reference to the difference in reading which you mention, we are surprised that there should be any considerable difference in the compression readings. We would venture to suggest, that the steel nipple (which is 1 1/4" long) and which you have added to the nipple of the disc valve itself, may account for the difference in the readings. Although the action of lifting the little platinum disc valve takes but a short time, whilst this occurs, and whilst it is returning to its seat, the gases are free to pass in and out to the gauge hence a little lag and a certain amount of leakage. contd. | ||