Couplings are color coded by shape so you can’t mix hose lines. Only plugs and sockets of the same color and coupling size will fit together. A complete coupling consists of a plug and a socket (both sold separately) that connect and disconnect quickly. Use them if you need frequent access to a line. Plugs and sockets are brass for good corrosion resistance.

Plugs are also known as nipples.

Sockets have a shut-off valve that stops the flow when the coupling is separated, so air or water won’t leak from the line. They are push-to-connect style. To connect, push the plug into the socket until you hear a click. To disconnect, slide the sleeve on the socket forward until the plug ejects.

Plugs and sockets with a barbed end insert into plastic or rubber hose and secure with a clamp or a crimp-on hose ferrule.

NPSF (National Pipe Straight Fuel) threads are compatible with NPT threads.

Note: To ensure a correct fit, make sure that the plug and socket have the same color and coupling size.