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).
National Physical Laboratory report on compression and blowing out tests for Wills Pressure Filled Joint Rings.
| Identifier | ExFiles\Box 86\1\ scan0084 | |
| Date | 10th August 1932 | |
| NATIONAL PHYSICAL LABORATORY. Report on tests of Joint Rings submitted by MESSRS. WILLS PRESSURE FILLED JOINT RING, LIMITED. COMPRESSION TEST. CHANGE IN EXTERNAL DIMENSIONS. N.P.L. Eng. Dept. Test Mark. | Material. | External Diam. ins. | Internal Diam. ins. --- | --- | --- | --- | | Before Test. | After Test. | Before Test. | After Test. | | Max. | Min. | Max. | Min. | Max. | Min. | Max. | Min. GLE 1. | Copper. | 3.70 | 3.67 | 3.75 | 3.71 | 3.32 | 3.29 | 3.29 | 3.26 GLE 4. | Monel metal. | 3.75 | 3.67 | 3.79 | 3.71 | 3.37 | 3.30 | 3.33 | 3.25 BLOWING OUT TEST. The apparatus employed is shown in diagram on Page 15. The ring is fixed between two smooth metal faces by means of a central bolt. The superheated steam is supplied through the hollow bolt to the space inside the joint ring. A small flow of steam is maintained by opening the drain valves to a small extent. The apparatus is well lagged and the temperature is observed by means of a thermojunction enclosed in a tube in place of the Platinum-resistance thermometer shown in the drawing. The joint was tightened up until no leakage was apparent at a pressure of 35 lbs./sq. in., and the torque applied to the spanner was measured. The pressure of the saturated steam was then increased gradually to 250 lbs./sq. in. The steam temperature was then increased gradually to about 1,000 degrees F.{Mr Friese}, and was maintained in excess of this temperature for at least 20 minutes. Date: 10th August, 1932. 14 TECHNICAL AND GENERAL DESCRIPTION. WILLS PATENT PRESSURE FILLED JOINT RINGS are hermetically sealed metallic rings, containing gas under pressure. The actual construction of the ring is achieved by manipulating the metal or tube, which may be copper, nickel, Monel, or other suitable metal, into the required form—round, oval or other shape necessary,—the two ends being welded together. The rings are filled with a non-explosive gas under pressure, providing a considerable degree of resilience cold. A definite increase in resilience is obtained from any increase in temperature. The internal pressure may be varied to suit particular applications. Pressures in excess of those which are to-day standard practice can be successfully held with these rings. The gas used to create the internal pressure remains in a gaseous state over a very wide range of temperatures, and does not liquefy until a very considerable drop below zero centigrade has been reached. The joints cannot blow out under working conditions, and can be used repeatedly. It is possible to break a joint by unscrewing the nuts until the joint leaks copiously, and to remake the joint by simply screwing up the nuts again. This can be done an indefinite number of times, the joint under these conditions being free from any possibility of blowing out trouble, as may be seen in the figures on page 4. 7 | ||