I was planning on using a Festo fitting for the fuel fill line on my UAT. I have heard that they can leak air under suction and that the connection to the UAT is a bad place for an air leak.

Do you guys use festo fittings here? If so, do you use the one way valve, a ball valve or a conection with a blanking plug? Do you prefer the blanking plug that come with the UAT? is there a better method?

Thanks