[david.small]

I found whilst checking TADS that one of them assumes a restrictor is fitted to a (mogas) fuel return, Because the TAD relates to the tubing that can be used rather than the restrictor itself there is no guidance included as to restrictor installation. I understand the restrictor allows vapour to escape via the fuel return to the wing tank. A 'T' piece restrictor was installed, with no operational problems encountered and bubbles can be seen in clear tubing forming part of the return line. The trunk of the' T' piece has the restrictor hole with fuel pumped along the horizontal part of the T direct to the carb. My inspector wonders whether the T needs to be inverted to work properly by allowing bubbles to escape vertically up the trunk of the 'T'? I have not seen any instructions indicating this is essential for restrictor installation. Reworking the pipework to invert the T would be a challenge with re-routing. Any insight into correct installation/operation of a 'T' piece fuel return restrictor gratefully received!