A pipe fitting used to connect two sections of pipe without use of threads.
The dresser coupling is named for its inventor, Solomon R. Dresser. The coupling was once widely used to make the connection between a service station suction pump and the end of the product line extending upward in the pump island. A dresser coupling is also known as a slip joint.
A dresser-type coupling is an unthreaded fitting. Sleeves on the coupling slide over the pipe ends to which they are to be connected, rather than attaching by threads.
In an earlier day, if a new dispenser was positioned on a pump island, and the installer discovered the presence of a gap between the pipe on the bottom of the dispenser and the pipe to which it was to be connected, he simply used a dresser type coupling to make the connection. One sleeve on the coupling was pushed down over the lower pipe; the other sleeve was pushed up over the pipe in the bottom of the dispenser.
This made it easier to connect the two pipe ends, even though a space separated them. Unfortunately, however, these couplings did not always hold. Leaks were not uncommon in installations where couplings had been used. Most industry fire codes and recommended practices now prohibit use of dresser type couplings beneath dispensers.