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).
Blueprint showing a cross-section of a radiator overflow valve.
| Identifier | ExFiles\Box 150\2\ scan0156 | |
| Date | 5th November 1938 guessed | |
| PLUG SCREW FIBRE WASHER. CONICAL SPRING. PHOSPHOR BRONZE BALL VALVE BODY. RADIATOR OVERFLOW VALVE. ROTHERHAMS COVENTRY. REF No 566. | ||