Abstract: A vent pipe and system formed from such vent pipes is provided. The vent pipe includes an inner casing, an outer casing surrounding the inner casing, and an insulation material between the inner and outer casings. The vent pipe also includes, a male end portion, a female and portion for receiving a male end portion end of another vent pipe, the female end portion being opposite the male end portion. The vent pipe further includes a first flange extending from the male end portion, and a second flange extending from the female end portion for mating with the first external extending from the male portion of another vent pipe.