Uniseals
Uniseals are very easy to use and perform a similar function to that of screw style bulkheads. Uniseals are great for applications where the seal may need disassembled occaionally or the seal is not on a flat surface such as acrylic tube.
All that needs to be done is like a bulkhead take a hole saw and make the proper sized hole in the item and then insert the Uniseal. After the Uniseal is in place, you can slide a piece of pipe into it, the pressure of the pipe pushing outward on the Uniseal is what makes the seal. On occasion you might have to apply light lubrication (often water works) to the pvc or the uniseal to get it slide in.