Fire brigade coupling
Fire brigade couplings are hose couplings for connecting fire hoses and fittings . A distinction is made between pressure couplings , suction couplings and fixed couplings . Blank couplings and transition pieces represent special cases . The couplings and transition pieces belong to the fittings for water transport.
The most common fire brigade coupling in the German-speaking area is the Storz coupling .
history
The Storz coupling was registered for a patent by Guido Storz in 1882 and supplied by the company Zulauf & Cie. manufactured. However, it did not spread throughout Germany in the fire brigade system until 1933, after it was prescribed as a standard coupling for the German fire brigades after a major fire in Öschelbronn . Luitpold Schott played a key role in the use of aluminum couplings for fire services in Germany. The couplings were described in the FEN 301–316 standards and had to be converted by 1943. In recent years, manufacturers in China have started producing Storz fittings, system parts and folding hoses, which means that Storz-compatible products have recently become very cheap, but show deviations in strength.
technology
The Storz coupling is a symmetrical hermaphrodite coupling, ie the connection fittings to be coupled are identical on the coupling side and can be connected as required. Unlike z. B. with screw systems (the two ends of a hose or a fitting are different here) so it is not necessary to pay attention to the assignment of internal to external thread. By eliminating this restriction, handling the Storz system is much faster and easier than is the case with non-hermaphrodite connection systems. This is a valuable advantage, especially in an emergency (fire service).
Unlike the screw couplings widespread in the Anglo-Saxon region, the Storz couplings are not screwed, but the connection is made according to the principle of a bayonet lock . The claws (technically speaking: cleats) engage in the corresponding contours of the counter-coupling and are locked there by turning the two half-couplings. In contrast to many other systems, the outer shape of the Storz coupling fittings is circular without points and corners and is therefore pleasant to the touch and pleasant to use as well as insensitive to dirt and wear and tear. The Storz coupling parts (hose couplings and threaded pieces) are now usually made of aluminum and aluminum alloys (in the early days the couplings were made of brass and therefore much heavier, which is a disadvantage in use). The aluminum couplings are pressed (forged) for the needs of the fire brigade, water supply and plant construction, cast variants (often from the Far East) do not have the necessary strength. The seals for these couplings are mainly made of nitrile rubber . Couplings made of brass, gunmetal and stainless steel are used in the areas of drinking water supply, in the shipping industry, in the food sector, the chemical industry and in other special cases. There are seals made of EPDM , silicone , Viton and other materials for these couplings .
Storz couplings are used almost everywhere where flat or dimensionally stable hoses are used that exceed the garden hose dimensions (1/2 and 3/4 inch nominal diameter), e.g. B. in industry, agriculture, construction, shipping, municipal operations, supply and disposal as well as in horticulture and fish farming.
The Storz-D couplings are seldom used in normal fire services, such as a suction hose for foam compound. However , they are found more often in stationary fire protection, such as bucket sprayers or wall hydrants .
Hose coupling systems
Pressure coupling
Pressure couplings are used to connect pressure hoses. They consist of a rotatable lug part, a connecting piece, a locking ring and a sealing ring with a pressure lip. A particular advantage of the Storz system (in contrast to GEKA, for example) is the rotatable connection of the lug part and hose nozzle (with its sealing lip), which means that the seals that are pressed against one another do not have to be rotated when coupling, which makes coupling much easier protects the seals. Storz couplings up to size B can in most cases be connected and disconnected by hand without tools (coupling wrench) in a depressurized state. Couplings of size D can also be uncoupled by hand after double kinking the hose when pressurized. This allows the line to be lengthened or shortened, or hollow jet pipes or other add-on parts to be added or removed during use, without the line having to be depressurized.
| size | Lug spacing [mm] |
Hose diameter [mm] |
standard |
|---|---|---|---|
| A. | 133 | 110 | DIN 14323 (originally DIN 14300) |
| B. | 89 | 75 | DIN 14303 |
| C52 | 66 | 52 | DIN 14302 |
| C42 | 66 | 42 | DIN 14332 |
| S32 | 66 | 32 | DIN 14330-1 |
| S28 | 66 | 28 | DIN 14330-2 |
| D Note 1 | 31 | 25th | DIN 14301 |
There are also "special sizes" of Storz couplings that are not found in the fire service:
- Couplings of the Storz 38 type (lug spacing 51 mm, i.e. a size between D and C), which is particularly suitable for hoses with a nominal size of 1 "to 1.5".
- Deutsche Bahn often uses Storz 38 on the hoses to fill the water tanks in passenger trains.
- The largest Storz coupling, type F, is mainly used in water management at mobile pumping stations.
- There are also other Storz special sizes, but none of them are very common.
- The Storz C size is the variant of the system that is manufactured in large numbers. Storz couplings are available up to size 12 ".
Suction coupling
Suction couplings are used to connect suction hoses. They consist of a rotatable lug part, a longer connecting piece, a locking ring and a sealing ring with pressure and suction lip.
| size | Lug spacing [mm] |
Hose diameter [mm] |
standard |
|---|---|---|---|
| A. | 133 | 110 | DIN 14323 |
| B. | 89 | 75 | DIN 14303 |
| C. | 66 | 52 | DIN 14321 |
| D. | 31 | 25th | DIN 14301 |
The seals are designed for both suction and pressure operation. The suction couplings are more difficult to couple than the pressure couplings.
Fixed coupling
Fixed couplings (threaded pieces in many variants) are used to connect hoses to fittings. They are firmly screwed on one side with a pipe thread on a water-bearing fitting or on a hydrant . On the other hand you can connect the usual couplings of a pressure hose or a suction hose . They are mostly made of aluminum , for HD (high pressure) made of brass . For use in hazardous goods areas, however, they are also available made of stainless steel and non-sparking brass alloys. They consist of a lug part with a thread, a seal for suction and pressure purposes and a flat sealing ring. In Germany the following standardized fixed couplings are used by the fire service:
- A with rubber sealing ring (DIN 14309)
- B with rubber sealing ring (DIN 14308)
- C with rubber sealing ring (DIN 14307)
- D with rubber sealing ring (DIN 14306)
- A with metallic sealing surface (DIN 14319)
- B with metallic sealing surface (DIN 14318)
- C with metallic sealing surface (DIN 14317)
The threaded pieces (fixed couplings) with metallic sealing surfaces can only be connected with hose pieces, these always contain rubber seals. Threaded pieces with metallic sealing surfaces avoid the problem of rubber aging (cracks, embrittlement, crumbling) and are therefore mainly used for permanently installed fittings in buildings (e.g. extinguishing water feeds), so that there is no maintenance effort (long maintenance intervals) and the function in the In the event of a fire.
Blind coupling
Blank couplings (i.e. end caps for temporarily unused Storz connections) are used as a seal on fittings to protect them (e.g. against the ingress of dirt into pumps) and must not be pressurized if the line cannot be released ( Risk of accident when loosening the blind cover under pressure). They consist of a lug part, cover, locking ring and sealing ring. German fire brigades use four standardized blind couplings:
- A (DIN 14313)
- B (DIN 14312)
- C (DIN 14311)
- D (DIN 14310)
Transition piece
Transition pieces are used to connect couplings of different sizes, e.g. to reduce a hose line from C to D. They therefore consist of two differently sized lug parts (e.g. C and D), a correspondingly reducing middle piece, two sealing rings and, depending on the size, a locking ring with threaded pins for a firm hold. In Germany, three transition pieces are standardized and used by the fire service:
- AB (DIN 14343)
- BC (DIN 14342)
- CD (DIN 14341)
Situation in Switzerland
The same couplings are used in Switzerland as in Germany. However, they are not named according to their type, but rather according to the inner diameter of the coupling.
- A = 110s
- B = 75
- C52 = 55 (effective 52 mm)
- C42 = 40s
- D = 25s
Historic couplings
Knaust coupling
While the Storz coupling was already common in Germany, in Austria-Hungary the K 52 coupling, supplied there since 1906 by the Viennese company Wm. Knaust (and patented earlier), was still used as a standard coupling for pressure hoses. Like the Storz coupling and the GEKA coupling, it is symmetrical, so that the same couplings are used on both hose ends. Since the lugs of the Knaust coupling are very stressed due to their exposed arrangement and are sensitive to impact, these couplings were made of brass , making them much heavier than today's couplings. The Knaust system was in use in Austria until World War II .
See also
- Claw coupling - different types, different manufacturers (GEKA (since the 1920s) and GEKA plus from Karasto; MODY, LUDECKE). for various media (compressed air, suction air, water, waste water, mortar powder, mortar suspension), for pressure or suction
- Hose connectors - and hose connections
literature
- Lutz Rieck: Die Rote Hefte, Booklet 6 - fire extinguishing fittings . Kohlhammer, Stuttgart 2000, ISBN 978-3-17-015171-0 , pp. 16-39 .
- Lothar Schott, Manfred Ritter: Fire Brigade Basic Course FwDV 2 . 20th edition. Wenzel-Verlag, Marburg 2018, ISBN 978-3-88293-220-1 .
- Diverse: Hamilton - Handbook for the fire brigade. Boorberg Verlag, 21st edition 2012. ISBN 978-3-415-04560-6 .
- Diverse: The fire brigade textbook. Verlag W. Kohlhammer, 2nd edition 2012. ISBN 978-3-17-022518-3 .
Web links
- Overview of fire brigade couplings, from then until today, from all over the world
- US patents to Storz
swell
- VDI magazine Vol. 81 No. 34, August 21, 1937
- 6th Implementing Ordinance for the Air Protection Act, Feb. 13, 1939
Individual evidence
- ^ Franz-Josef Sehr : Development of fire protection . In: Freiwillige Feuerwehr Obertiefenbach e. V. (Ed.): 125 years of the Obertiefenbach volunteer fire brigade . Reference 2005, ISBN 978-3-926262-03-5 , pp. 116-117 .