Couplings are used to quickly connect two even pipes with a tight, durable seal and a flexible joint. The Dresser coupling consists of one cylindrical middle ring, two follower rings, two resilient gaskets made up of a special Dresser compound and a set of steel track head bolts.Click to see full answer. In this regard, what is a PVC dresser coupling?PVC 2″ Dresser Coupling. This Dresser Fitting joins standard PVC (1/2-1-1/2″) in diameter pipes on new installations. PVC and slip-fit fittings are glued together with special PVC glue that’s designed to create a seal that is leak proof and durable like the Pvc pipe. how many types of coupling are there? 3.0 Types of Flexible Couplings Most small to medium size couplings are basically one of three types. Also, how does a Gibault joint work? Our Gibault Joint allows you to join together pipe of different sizes and types . The 4% of deflection allows the pipeline to be offset to a differant direction. Other available Joints: Tapered Gibault – to allow for reduction in line size.Do they make shark bites for galvanized pipe?1 Answer. The actual SharkBite push to connect fittings are not designed to press onto galvanized pipe. For mating your PEX to galvanized, SharkBite makes a threaded to press fit transition adapter. You will need to square cut the end of your galvanized pipe and then rethread it.