PVC Schedule 80 Pipe is for pressure applications, and has a thicker wall than Schedule 40 pipe. PVC Schedule 80 is highly durable, with high tensile and impact strength. It has better sound deadening qualities than PVC and ABS Foam Core pipes. Installation requires the use of primer and solvent cement.
I believe that if any rigid pipe is used, it should also be isolated from shock and stress by using adequate support, and flexible pipe (Trident 101/102) between the pipe, and any fixture mounted to the vessel (deck plate, holding tank, head, etc.).