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).
Specification and schedule of tests for 18 mm type sparking plugs for aero engines.
| Identifier | ExFiles\Box 58\2\ Scan105 | |
| Date | 1st April 1934 | |
| X1812 a R.D.E.2. Specification No.31. Issue No.1. April, 1934. Air Ministry. Directorate of Technical Development. (190225/32). This document is the property of H.M.Government. This document is intended for the use of the recipient only, and may be used only in connection with the work carried out for or on behalf of H.M. Government. The unauthorised retention or destruction of this document, or the disclosure of its contents to any unauthorised person, is forbidden. Attention is hereby called to the fact that failure to comply with any of the above instructions is an infraction of the Official Secrets Act. Note :- Any person other than the authorised holder upon obtaining possession of this document by finding or otherwise should forward it, together with his name and address, in a closed envelope to the Secretary, Air Ministry, Kingsway, London, W.C.2. Letter postage need not be prepaid; other postage will be refunded. Sparking Plugs - 18 mm Type for Aero Engines. Specification and Schedule of Tests. 1. This specification and schedule of tests consists of four sections as given below and includes the type tests which any type of sparking plug shall satisfactorily complete before being approved for general use on any Service engine together with the acceptance tests with which all subsequent production sparking plugs supplied for use on Service engines must comply :- Section 1: General Requirements. Section 2: General Conditions of Testing. Section 3: Type Tests. Section 4: Acceptance Tests for subsequent Production Sparking Plugs. Section 1: General requirements. 2. General. (a) The design of 18 mm type sparking plugs for aero engines shall be such that they are of the detachable type and maintain good gas tightness under adverse conditions of use. (b) The detail workmanship and finish is to be such as to give a sparking plug of the highest grade both in construction and appearance. All materials used in the construction of the plugs shall be of the best quality obtainable. Screw threads are to be correct and interchangeable to the standard gauges specified, and other machining is to be within the specified tolerance. | ||