Air Cannister for Desktop Air Compressor

This is a work in progress and would like to see any input or design changes to it. It is an attempt to make a printed air canister for a home made bench top air compressor. Yes i know it wont hold a lot of pressure or quantity of air, but i am open to any suggestions. It has an opening at each end for fittings and is in two parts as it is designed to be glued together. Im still new to 3d design and do not know how to make a closed cylinder from within freecad.