Abstract: An apparatus connects first and second conduits that convey a flow of gas. The apparatus includes a first flange element fixed to the first conduit, and a second flange element fixed to the second conduit. The flange elements are coupled together to permit fluid communication in an internal environment between the first and second conduits. At least one port is intermediate the flange elements to deliver a flow of purge gas therebetween. The at least one port may be located within a purge gas channel arranged in one of the flange elements. A pressure gradient of the flow of purge gas may substantially prevent at least one of fluid egress from the internal environment and fluid ingress from an external environment. Purge gas distribution systems and related methods are also described.