I am installing a 25' lgt pole on a 36" high concrete pole base at an outdoor fuel island (LPG). I have been told that I need to provide a seal off at the end of the conduit. The conduit is installed underground and to the center of the concrete pole base. Code states that class I, division II is the floor up to 18". My question is, do I still need a seal off if the conduit is 3' underground encased and exits the top/center of the concrete pole base to come into the bottom of the lgt pole?