STORZ couplings
STORZ couplings – general information
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.
There are two types of STORZ couplings: forged couplings (according to standards, e.g. DIN) and cast couplings. The cast couplings have lower material strength and are more prone to casting defects. They can only be used for low working pressure (max. up to 6 bar and for less critical applications). Tubes International offers high quality forged couplings with working pressures up to 16 bar as standard. Cheaper, cast versions are also available, they are marked with an asterisk (*) in the catalogue. (*).
As standard, STORZ couplings have a vacuum resistant lip seal designed for suction-delivery hoses. The couplings for delivery hoses (with a short hose tail) have a seal that is not resistant to vacuum. Aluminium STORZ couplings are fitted with a white nitrile rubber seal (NBR) as standard, brass couplings with a black NBR seal and stainless steel couplings with a Viton seal. Other types of seals are available and should be selected according to the table below.
| seal material | working temperature range | food applications | resistance to oils and lubricants |
|---|---|---|---|
| NBR | from -40°C up to +110°C | white – yes | limited |
| silicone | from -60°C up to +180°C | yes | no |
| viton | from -15°C up to +200°C | no | yes |
| EPDM | from -35°C up to +130°C | no | no |
Type of material:
Aluminium STORZ firefighting couplings
Brass STORZ firefighting couplings
Stainless steel STORZ firefighting couplings
List of products:
STORZ firefighting couplings with hose tail
STORZ firefighting couplings with hose tail for a clamp
STORZ blank cap standard, with lock
STORZ firefighting couplings with flange connection
STORZ firefighting couplings with male thread
STORZ firefighting couplings with female thread
Mounting brackets for STORZ firefighting couplings
Firefighting coupling reducers – STORZ
STORZ – safety locking clamps for couplings
STORZ fire nozzles
Accessories for STORZ firefighting couplings
Spanners for STORZ firefighting couplings
If you need help choosing a product or haven’t found the right one?
FAQ – STORZ couplings
STORZ couplings are couplings designed for fluid and bulk transfer systems. They are used in firefighting, irrigation systems, chemical industry, food industry, agriculture, etc.
The couplings feature symmetrical locking heads (no male/female difference) Therefore, they can be easily connected by turning them by 22°, either manually or with a spanner. It is important to connect the parts with the lugs spaced at the same distance and made of the same material.
The size of a STORZ coupling can be verified by measuring the distance between lugs (measured on the inside). Distance between the lugs: 31 mm, 44 mm, 51 mm, 66 mm, 81 mm, 89 mm, 105 mm, 115 mm, 133 mm, 148 mm, 160 mm, 188 mm, 220 mm, 278 mm.
The most popular sizes:
– size A: lug distance 133 mm,
– size B: lug distance 89 mm,
– size C: lug distance 66 mm,
– size D: lug distance 31 mm.
STORZ couplings can be classified by the type of connection and material.
The most common connection ends:
- STORZ coupling with a tail for suction-delivery hoses,
- STORZ coupling with a tail for delivery hoses,
- STORZ coupling with a smooth tail to mount a safety clamp,
- STORZ coupling with a female thread,
- STORZ coupling with a male thread,
- STORZ coupling with a flange connection,
- STORZ coupling dust cap,
- STORZ reducers (allow connection between different STORZ coupling sizes).
Material variations:
- Aluminium,
- Brass/Bronze,
- Stainless steel.
As standard, STORZ couplings come with a vacuum resistant lip seal designed for suction-delivery hoses. The couplings for delivery hoses (with a short hose tail) have a seal that is not resistant to vacuum. Aluminium STORZ couplings are fitted with a standard white nitrile rubber seal (NBR), brass couplings with a black NBR seal and stainless steel couplings with a Viton seal.
The manufacturing methods and working parameters are different. The cast couplings can only be used for low working pressure (max. up to 6 bar) and for less critical applications due to the brittleness of the components. The forged couplings are designed for more critical applications and can operate at a maximum working pressure of 16 bar.