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).
Deceleration test results for a recession valve under varying governor speeds and conditions.
| Identifier | ExFiles\Box 179b\4\ img028 | |
| Date | 11th April 1933 guessed | |
| RECESSION VALVE DECELERATION TESTS (1) GOVERNOR SPEED REDUCED FROM 80 to 30 M.P.H. Damper Speed R.P.M. | Time Secs. 80 to 30 M.P.H. --- | --- | Without Recession Valve | Ball Valve .015" Dia. Release Vent | Governor. | Damper. | Time lag Gov. to Damper. | Governor. | Damper. | Time lag Gov. to Damper. 90 | 3 | 11 | 8 | 3 | 10 | 7 180 | 3 | 15 | 12 | 3 | 15 | 12 360 | 3 | 15 | 12 | 3 | 15 | 12 (2). GOVERNOR SPEED REDUCED FROM 80 M.P.H. to NIL. Damper Speed R.P.M. | Time Secs. --- | --- | Without Recession Valve. | Ball Valve .015" Dia. Release Vent | Gov. 80 MPH. to Nil. | Damper 80 to 30 MPH. | Time lag Gov. to Damper. | Gov. 80 MPH. to Nil. | Damper 80 to 30 MPH. | Time lag Gov. to Damper. 90 | 3 | 6 | 3 | 3 | 7 | 4 180 | 3 | 6 | 3 | 3 | 8 | 5 360 | 3 | 6 | 3 | 3 | 8 | 5 "Compressor Oil" was used throughout the system. Damper temp. approx. 50°C. Hw/W.Bell. | ||