Can'ttell from your pic, but you normally want the vent as far above the tank as possible to prevent leaks when filling. IE: Hot summer day you fill up with gas that is a lot cooler from being stored in underground tanks. As it warms up it can expand and will overflow through the vent line as it has nowhere else to go.
Might check out Tanks inc. website
TANKS INC>

beer

Last edited by TJP; 09/05/20 12:23 PM.