Plugs and sockets with a shut-off valve have a valve that stops the flow when the coupling is separated, so air won’t leak from the line. Those with a clamp-on barbed end insert into a plastic or rubber hose and secure with a clamp or a crimp-on hose ferrule. Others with a push-on barbed end have sharper barbs than standard barbed hose fittings to grip rubber push-on hose with no clamps or ferrules required. The more you pull on the fittings, the tighter the hose will grip. To ensure proper connection, the barbed end has to be pushed in all the way, with the hose end concealed by the ring.
Plugs are also known as nipples.
Sleeve-lock sockets connect by sliding back the sleeve on the socket, inserting the plug, and releasing the sleeve. To disconnect, slide the sleeve back and pull out the plug.
Zinc-plated steel is stronger and more durable than other metals. It has fair corrosion resistance, so it should be used primarily in dry environments.
Brass is softer than other metals, so it’s easier to thread together. It has good corrosion resistance.
Note: To ensure a correct fit, make sure that the plug and socket have the same coupling size.
