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).
Redesign, material changes, and testing of spherical seated unions for standardization.
| Identifier | ExFiles\Box 34\2\ Scan009 | |
| Date | 19th December 1925 | |
| To BY.{R.W. Bailey - Chief Engineer} from E.{Mr Elliott - Chief Engineer} c. to CJ. c. to RG.{Mr Rowledge} c. to Hs.{Lord Ernest Hives - Chair} X2170 E2/M19.12.25. SPHERICAL SEATED UNIONS. X.2170 X.8180 X.4111 X.8190 We send you herewith drawing LeC.2183 shewing the above revised. This arises out of consideration of the models and enlarged scale drawings which you sent us. The union has not been altered in principle but the proportions have been modified to cut out excessive weight and to provide more joint face under the union where it squeezes the washer against the casting or other piece with which it is making permanent connection. Furthermore the idea is to use soft alum. washers under the unions since the amount of area available for the joint is quite unsuitable for fibre. The fibre we think would be squeezed out and crack. We are asking for the union nuts and bodies to be in Firths staybright steel. This will increase the strength and at the same time slightly reduce the weight. The union nipples should be in mild steel for oil pipes and in phosphor bronze for water and petrol connections. The union nuts have been improved in strength by adding somewhat to the thickness of the collar above the spherical seating. We carried out an actual test on the models you sent us and found that it required a considerable amount of force to burst the .312 nipple, and it was impossible to damage the ½" nipple with the ordinary standard spanner. A calculation shews that the efficiency of the union nut is in the neighbourhood of about 3% in the case of the nipple for the 1" dia. pipe and under these circumstances we find the stresses are quite reasonable with 100 lbs. exerted on the large shifting spanner applied to this union. We should be glad if you would take the necessary steps to get these revised unions tested for standardisation. E.{Mr Elliott - Chief Engineer} | ||