Hose coupling

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The hose coupling is the metal piece on the end of a hose to connect it to extra hose or hose appliances. It is usually made of steel, brass, stainless steel or aluminum.

Hose couplings come in many different styles:

"Air King" Universal Air Hose Coupling (see Dixon Valve)

A malleable iron or brass "quarter turn" "sexless coupling" usually found on pneumatic air tool lines such as used to supply jackhammers. The fitting is considered "universal" because a common 2 lug head is used on all sizes ranging from 1/4" through 1".

Cam & Groove Coupling

A quick connect fluid transfer hose coupling that consists of a male "adapter" and female "coupler". The "adapter" has a groove on the outside that is engaged by the "cam arms" on the outside of the "coupler" to effect a seal against the gasket inside the "coupler". They are most commonly found in petroleum or chemical applications.

"Boss" Ground Joint Coupling (see Dixon Valve)

A hose coupling primarily used for compressed air or steam. It consists of a stem, wing nut and spud. It seals as a soft copper seat located in the spud is drawn against the stem by tightening the wing nut.

Storz coupling

Storz connection on a standpipe.

A "quarter turn coupling", or "sexless coupling", commonly used to connect to fire hydrants, easy to connect, no particular male or female end, lugs are on inside of coupling. The standard coupling on fire hoses in Germany.

See Storz.

Guillemin symmetrical clutch

The Guillemin symmetrical clutch is widely used in France and in Belgium by firefighters to couple fire hoses. It is also commonly known under the name of DSP connector.

It can be fastened by hand, but it is also possible to use a tricoise wrench. It is also "quarter turn" and "sexless" (symmetrical).

Each end has a ring with two protuberances outside; when the ring turns, the protuberances lock to the hook of the other hose.

Barcelona coupling

It is the coupling used by the Spanish firefighters. It is a "sexless" coupling with 3 engaging lugs.

Spanish fire hose coupling.

Nakajima coupling

A "quarter turn" or "sexless" coupling used on fire hoses in Japan.

Gost coupling

A "sexless" coupling used on fire hoses in Russia.

Machino coupling

A quick connect and disconnect coupling used on fire hoses in Japan.

NST coupling

Side view of a 1.5 inch to 2.5 inch adapter.

National Standard Thread (NST), also known as National Hose thread (NH). The most common type of fire hose coupling used in the USA. The male and female straight (non-tapered) threads screw together and the connection is sealed with a gasket.

Expansion Ring Fire Hose Coupling (see Red Head)

Commonly used on lay flay fire hose, it has the advantage of providing no flow restriction, as the expansion ring is expanded to match the inner diameter of the hose. They are installed with special machinery using a drawbar expander. In the USA it is most commonly supplied with NST (NH) threads.

Mulconroy/Holedall Swaged Hose Coupling (see Dixon Valve)

Commonly found on larger diameter hoses used in higher pressure applications or where the hose is exposed to higher end pull (i.e, Oil Suction & Discharge (OS&D) hose). They are installed with special hydraulic ram machinery and special dies.

Holedall IX Internally Expanded (Internally Swaged) Hose Coupling (see Dixon Valve)

Used in higher pressure applications, or where the hose is exposed to higher end pull, or where a full flow is required. They are installed with special hydraulic pull bar machinery using special pull plugs.

Holedall (Scovill/Rostra) Internally Expanded Hose Coupling (see Dixon Valve)

Used primarily on fuel oil hose applications, where a full flow is required. They are installed with special hydraulic pull bar machinery using special pull plugs.