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).
Comparison of experiences with conical nipple and spherical union pipe types.
| Identifier | ExFiles\Box 141\2\ scan0122 | |
| Date | 17th September 1935 | |
| To. Mr. Wor.{Arthur Wormald - General Works Manager} Slt/AEM. Hs.{Lord Ernest Hives - Chair} WB.{Mr Brazier/Mr Bell} SY. Sft.{Mr Swift} PHIC. Rm{William Robotham - Chief Engineer} Hq/SB{Mr Bull/Mr Bannister}22/HR.17.9.35. re PIPE UNIONS. ---------------- With reference to your E6/HP. 13.9.35., we give you below our experience with various types of unions on cars in service. CONICAL NIPPLE TYPE. This was used as standard until some ten years ago when it was displaced by the spherical type. We had few faults to find with it, and we had practically no trouble with oil leaks. The Silver Ghost engine even today presents a much cleaner appearance than modern engines due to the absence of oil leaks from the various unions, although it will be remembered that there were many more unions and pipes. Its only fault was that the pipe had to be properly lined up with the union. With small diameter pipes this presented no difficulty. Pipes of .500" diameter or so were more difficult to line up, but having once been properly set, the joint could be depended upon to remain oil tight. SPHERICAL UNION TYPE. So far as we can see, the only virtue of this type is that it permits of some mis-alignment of the pipe when erecting. From the point of view of oil tightness we think it is definitely inferior to the conical type. One has certainly got to tighten the nut pretty hard to stop leaks. Would not this type be better with a smaller sphere for a given size of union in order to make the joint more towards the outside diameter of the sphere, thus getting a better wedging action more approaching the conical type? 1 CONTD. | ||