Fuel Tank and UHT on TREX 700 Wren 44i

[Drummer_andydrummer]

Hi there,

Im new to turbines and I was wondering if anyone give me a diagram on how the UHT and fuel tank is connected seems very confusing with 3 connections on a fuel tank and the same on the UHT.. Which connections you use for what inc the clunk, etc... many thanks

[cbergen]

Consider whats needed in the fuel system, fuel going TO the turbine, a way for air to replace the fuel being taken out of the tank, and a way to refill the tank.

For fuel going to the turbine, the "clunk" line is used, If you have multiple tanks, then each tank has a clunk or pickup line. This line either feeds the turbine directly, or feeds the next tank in line.

While fuel is being sucked out of the tank, there has to be a way for air to to replace the fuel otherwise the tank will attempt to shrivel up.... So we use a vent line. Now in the case of multiple tanks, the clunk line from one tank will feed the vent line of the next tank so the fuel feeds from one to the other.

And of course you need a way to refill the tanks when you want to go fly. Now one COULD use the clunk line to refill, but it's simply easier to have a dedicated fill line. It's important to ensure that the fill line cannot leak air into the tank when operating the turbine, I use a clamp AND a plug for security. In the case of multiple tanks, it's not necessary that each tank has a fill line, simply fill the one closest to the turbine (the UAT) and it will fill the other tanks through the vent/clunk lines.

HTH...

[Drummer_andydrummer]

Thank you for that information made things clear :-)