Radium Engineering pumpless high volume fuel surge tank was designed for users that already have a secondary external fuel pump. The HVFST (High Volume Fuel Surge Tank) is ideal for very high flow external fuel pumps requiring a large reservoir and feed line.  It provides a reservoir from which an external pump can draw from. It features a single PTFE pick-up tube rather than an integrated fuel pump. Radium does not recommend mounting this surge tank horizontally, as the pick-up may be prone to drawing in air pockets.

A lift pump is required to supply the HVFST with fuel. Excess fuel is then routed back to the main tank (or fuel cell). The pump feeding the engine, then draws it s fuel from the surge tank, with excess returning from the regulator back to the surge tank.

The 20-0081 HVFST uses a larger canister (2.21 liters 0.58 gallons). It uses a single 5 8 (-10AN) pick-up tube in the center. 

The 3 black ports are used for fuel entering and exiting the surge tank. The High Volume Fuel Surge Tank includes three -6AN male fittings. However, if -8AN and or -10AN port fittings are required, they can be purchased separately.