Fuel system and filter

The 912 Installation manual doesn't directly specify the requirements for the coarse filter. The entire section reads:

"COARSE FILTER
On fuel tank as per valid certification."

What 'as per valid certification' actually means will depend on how your aircraft is certified. I'm unfamiliar with the requirements for ULM aircraft in France but I'd guess it would be acceptable to comply with CS-VLA 977 (b), which states:

"There must be a strainer at the outlet of each fuel tank. This strainer must -
(1) Have 3 to 6 meshes per cm;
(2) Have a length of at least twice the diameter of the fuel tank outlet;
(3) Have a diameter of at least that of the fuel tank outlet; and
(4) Be accessible for inspection and cleaning."

This equates to a mesh pitch of about 1.7 to 3.3 mm. (or for our US friends, 8 to 16 meshes per inch, per FAR 23.977)

Accounting for the thickness of the wire, this should filter out particles larger than approximately 1200 to 2400 µm.

For example:

Many thanks @tim B, exactly what i need ! perfect !  

All the best. 

Nicolas.