Duplex Fuel Selectors are valves that have two seperate compartments so that two independent fuel
lines can be switched simultaionusly. This makes them ideal for fuel injected engines where there
needs to be a return line. The great aspect of these valves is that the fuel can be returned to the
same tank from which it was drawn thus preventing dumping fuel overboard. There are 4 types
produced by Andair.
The FS15 Duplex fuel selector is a 1/4" feed and return valve, allowing you to switch between two
fuel tanks (LEFT - RIGHT) of a fuel injected engine.
This valve has a similar main body as the FS15x2 and is supplied with a silver colour anodised fascia plate.
The FS22 Duplex fuel selector is a 3/8" feed and 1/4" vapour return valve, allowing you to switch between two
fuel tanks (LEFT - RIGHT) of a fuel injected engine. It was designed with the Rotax 914 in mind, but is suitable for other applications.
This valve has a similar main body as the FS20x2 and is supplied with a silver colour anodised fascia plate.
This Duplex fuel selector is a 3/8" feed and return valve. Therefore allowing to switch between two fuel tanks (LEFT - RIGHT) of a fuel injected engine of up to 200 HP.
This particular Duplex valve has a 3/8" compartment at the top of the valve, and a 1/2" section
at the bottom. The 1/2" part would be used for the feed and the 3/8" for the return.
The FS2020 & FS2520 Duplex Selectors are supplied with a black anodised engraved face plate and a larger
red lever. (Slightly larger than the standard 3/8" valves) and all three can be supplied with lever extensions.
All of Andair's Duplex Fuel Selectors conform to FAR 23.995, in particular subsection (g), which states that:
Fuel tank selector valves must--
(1) Require a separate and distinct action to place the selector in the "OFF" position; and
(2) Have the tank selector positions located in such a manner that it is impossible for the selector to pass through the "OFF" position when changing from one tank to another.