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).
Positioning, venting, and pressure testing of a tank unit.
| Identifier | ExFiles\Box 61\3\ scan0082 | |
| Date | 29th July 1930 | |
| Page 2 (4). It is desirable to fit the unit right up against a surge baffle, so as to give the most vigorous possible pumping; the distance between this baffle and the next to be if possible not less than 10 to 12 inches. (5). The ideal position for the unit fore and aft in the tank is one quarter from the leading edge and three quarters from the rear edge of the tank. This with the existing distance between the front and back tubes of our dash unit. (6). The Sprengel pumping tubes pass direct to atmosphere, and are protected against the entry of mud and water by a covering dome. (7). The venting arrangements are through (1) the top plate, (2) the first baffle, (3) the second baffle. These appear to give an ample outlet for air and petrol; also for prevention of splash. (8). The bell vent discharges horizontally through one of the holes of the top baffle compartment. (9). Tests have been made with this unit inserted in a sealed tank completely filled with petrol; one of your normal gauges with 14" scale, as proposed, being connected by a normal air line to the air line connection. A pressure of 6 lbs. per square inch was then introduced on to the petrol in the tank, and the pressure maintained at that figure. The tank vent and the bell vent were allowed to continuously discharge petrol under this pressure. The reading on the gauge scale did not increase more than 10% of the total range of the scale under these conditions. We therefore believe that this unit carries out the conditions which were mentioned in our former correspondence, namely, that given abnormal pressure conditions at filling up, the single line, used in conjunction with this venting arrangement and tank unit, would be proof against these pressures. [Handwritten in left margin, pointing to 'normal gauges'] a standard dash unit | ||