07.15 Can the inlet flow to the day tank be precisely controlled?

There are 2 reasons to more precisely control day tank inlet flows: (a) to make sure that downstream day tanks are not starved for fuel flow, and (b) to make sure that the overflow protection mechanism, either gravity overflow or pumped overflow, is greater than the maximum inlet flow.

In general, a properly sized inlet control valve will allow for these functions without additional measures. A 12 mm solenoid valve at 170 kPA differential pressure will flow about 70 LPM. This allows for (a) a maximum normal engine consumption of about 12 LPM, (b) adequate capacity where the engine return flow goes directly back to the bulk tank requiring a maximum flow of about 35 LPM, and (c) adequate capacity for a 120 LPM rated return flow pump.

More precise flow control can be achieved by using a flow regulating valve, such as the one manufactured by Kates, that has been proven in fuel service. The device does have relatively small orifices which must be protected by a properly sized inlet strainer.