We can fabricate our tank liners to handle outlets and pipe penetrations. Piping that is straight but comes in at an angle to the tank can be lined but piping that has a bend isn’t as straight forward.
An outlet with a 90o bend requires some minor tank modification in order to be properly lined. An outlet can’t be manufactured that has such a bend. Furthermore, if it could it would most likely collapse at the bend and block the flow of the outlet.
To handle this type of plumbing you need to refit the piping. Create a straight pipe with a standard flange face fitting. This part of the outlet would be part of the PVC liner. From that piping attach a flange face with a 90o bend and continue on with the piping. Similarly if this is a penetration where a boot will be fabricated to cover the outside of the pipe make a straight pipe and after the liner boot is installed come off that pipe with a 90o bend.
Simple modifications like this allow for a tank liner to fit well and provide maximum service life.