Fuel reserve tap accessory

[Nick Lettington]

That's reet clever! Fuel flows in from A via B in the 'on' position. As air enters from the vent pipe at B, it prevents  a syphon forming. Whe the fuel level in the tank reaches the same level as B it acts like a baffle and stops the flow. The reserve setting directs flow straight from A to C, allowing the tank to empty.

[Howard Wright]

Hi Nick

Thanks, I’d got most of the way there but your explanation is very concise.

Cheers

Howard

[Nick Lettington]

And I'd be brave enough to guess that the internal passages look something like this... at least without one to look at, I can't see how else the geometry makes sense. 

   

[Dave Mann]

Try a tee port cock