STORZ symmetrical couplings were designed in 1882 by Guido Storz and patented in Switzerland in 1890. In many European countries they became the standard couplings for fire fighting hoses and equipment. Hence STORZ coupling is popularly called a fire fighting coupling or fire hydrant coupling. Today it is widely used in fire protection systems, but also as a coupling for general industrial application for liquid and dry loose substances in the chemical industry, food industry, agriculture, construction, irrigation systems and sewage transport, in road tankers for loose bulk substances, etc.
STORZ couplings have two lugs on the swivel head which is mounted on the hose fitting and secured with a wire ring, or two lugs on the fixed head with a threaded connection end which is screwed onto the threaded connection of the pipework e.g. fire hydrant. STORZ couplings are connected really quickly as only 1/4 of a turn is needed to join two parts – this is their main advantage. High, unrestricted flow rate, resistance to contamination and external damage are another important features of the couplings.
STORZ couplings made of aluminium are the most popular (cast or forged). The cast couplings have lower material strength and are more prone to casting defects. They can be used only for low working pressure (max. 6 bar) and for less demanding applications. As a standard we supply the high quality forged couplings with working pressure up to 16 bar, however we also stock the less expensive cast couplings.
- STORZ couplings in aluminium come with white NBR rubber seals as a standard.
- Brass couplings, often used in the shipbuilding industry, have black NBR rubber seals.
- Stainless steel couplings come with Viton seals as a standard.
The size of STORZ couplings can be defined either by the traditional indication relating to a hose nominal diameter (e.g. 52-C) or by internal lug spacing. Only the elements with the lugs spaced at exactly the same distance can be joined together.
The range of STORZ couplings includes hose fittings, blank caps, adapters with BSP thread or with a flange, swivelling couplings, reducers, connectors with BSP thread designed to build adapters and reducers, hose connectors, STORZ hook wrenches, seals for delivery hoses and seals for suction-delivery hoses (the most popular).
The seals are made of NBR rubber (white or black), Viton, EPDM, silicone and other materials. Silicone seals are often used in STORZ couplings for pneumatic transport in road tankers, as they are resistant to temperature. Water jets with STORZ couplings complement the range. They are used e.g. in road building.