ProVent introduces a new EZ Mechanical Coupling. The coupling has a flexible rubber expansion joint explicitly made for PVC DWV plumbing stacks. Stacks require at least a 1/2-inch movement at every other floor to protect the PVC branch piping from possible breakage. This tested inexpensive expansion coupling will compensate up to 3/4-inch up or down movement at every floor level. Four-story or more apartment/hotel type buildings need this protection for both concrete and more importantly for wood structures with lots of shrinkage.
MORE INFORMATION: proventsystems.com