In the plumbing trade a Yoke is usually a brass casting that holds both the hot and cold water valves and the mixing chamber for the water. May also refer to an assembly of copper or other metal which serves the same function.
A York flange is a type of plumbing fitting that is inserted into the top of a hot water cylinder and purges the hot water of air before it is drawn off into the outlet. Normally york flanges are used in the feed for shower pumps.