Fire hose
A fire hose is an integral piece of equipment of the fire brigade and the task, which has extinguishing agent water or water / foam mixture to about distances promote . The hoses can be roughly divided into two types: hoses through which water or another non-aggressive liquid can be sucked (suction hoses) and hoses that convey water, water-foam mixture, CAFS foam or other non-aggressive liquids under pressure ( Pressure hoses). In Europe , the lug coupling has become established for connecting the hoses (with the exception of Great Britain and Italy). The lug coupling does not have a uniform shape in the other countries either. While the Storz coupling is used in Germany , Austria , Switzerland and the Netherlands , French and Belgian fire brigades use the Guillemin, which works according to a similar principle, while Spanish fire brigades use the Barcelona design, Sweden and Norway each have a country-specific standard, and it is found in Eastern Europe one the Russian Gost clutch. All of these couplings are hermaphroditic, which means that, in contrast to the threaded coupling common in the USA and Great Britain , there are no different couplings at the ends of the hoses, so it does not matter which side of the hose is connected to the coupling of another hose. The size designation (A, B, C, D) is derived from these fire service couplings in Germany and Austria. A hose with z. B. the designation pressure hose C-42-15 denotes a hose with Storz pressure couplings of size C, inner diameter 42 mm and a length of 15 m. Responsible standards for Germany are DIN 14811, in Austria ÖNORM F2105.
Pressure hoses
Pressure hoses have the primary task of conveying water. They are mainly used in fire fighting , where extinguishing agents can be emitted with appropriately selected jet pipes . However, they can also be used to divert dirty water during flood operations or the like. For this reason, they are generally not considered to be permitted for pumping drinking water - for example for supplying field kitchens , treatment centers or localities, etc. For the pumping of drinking water, specially marked, otherwise structurally identical pressure hoses are used, which are also subject to different legal regulations.
Due to their primary function, pressure hoses consist of a seamless, round woven plastic fiber fabric ( polyester ) and are rubberized on the inside. They are generally flexible in shape, which means they fold flat when not under pressure. This has the advantage that they can be transported in a space-saving manner. The usual operating pressure is up to 17 bar, but the test pressure is 12 bar for A and F hoses and 16 bar for B, C and D hoses. The bursting pressure is 25 bar; d. This means that new hoses must withstand 24 bar without bursting. In practice, however, brand-new hoses only burst at a pressure of 50–60 bar. The 5 m filling hose is excluded from this pressure test.
| size | Diameter [mm] |
Standardized lengths A1 in meters (internal volume in liters ) | ||||
|---|---|---|---|---|---|---|
| 5 | 15th | 20th | 30th | 35 | ||
| F A2 | 150 | x (354) | ||||
| A. | 110 | x (48) | x (190) | |||
| B. | 75 | x A3 (22) | x (88) | x A4 (155) | ||
| C. | 42 | x (21) | x (28) | x A5 (43) | ||
| 52 | x (32) | x (43) | ||||
| D. | 25th | x (2.5) | x (7.4) | |||
| HD | 28 | x (9.2) | ||||
Any other hose lengths are also possible, but these are then not standardized and / or are very uncommon.
Size F pressure hoses are mainly used for pumping large amounts of water in connection with special pumps and laying systems. These are used by the fire brigade (e.g. as roll-off containers HFS ) and by the THW .
Pressure hoses of nominal size A are mainly used by highly specialized fire brigades in large chemical companies for large conveying capacities. They are also used by units of the disaster relief service to convey large quantities, for example during pumping work after floods. On the other hand, A pressure hoses are rarely used by individual public fire departments.
Pressure hoses of nominal size B, C and less often D are used by all fire departments. Pressure hoses of nominal size B are used for pumping water from hydrants to the pump, from the pump to the distributor and, if necessary, to the B jet pipe or foam jet pipe with B connection. Water cannons and reversible pipes with a B connection are also operated.
In the area of fire fighting, especially internal attacks, the fire brigade traditionally uses pressure hoses of nominal size C, as these are mechanically easier to handle and the amount of water given off with a C jet pipe is often sufficient. B pipes are only used in large fires (definition in NRW: more than three C radiant pipes in use).
Usually, the ready-to-use hoses are folded twice and then rolled and, for some users, held together with a belt, hose carrier or hose belt ( hose package ). Both couplings are on the outside of the rolled hose, which makes it much easier to roll out the hose. Another option is to store the hoses placed in bays in hose baskets . A cage usually holds three C-hoses coupled to one another and thus offers the fire fighting team enough hose reserve.
But they can also be folded up like continuous paper , and with some hose trolleys they can also be stored rolled up twice so that the hoses coupled to one another can be laid out directly from the slowly moving hose trolley.
Also, hose reels are a means by which already zusammengekuppelte hoses can be rolled up and pulled down when needed in a short time.
If the hoses can always be rolled out relatively easily, then for any type of storage at the end of the mission, rolling up the hoses is a tiresome and time-consuming job. Used hoses are simply rolled up and transported. Hose reels or other devices can make this work a little easier, but not completely remove it.
In the past, pressure hoses were made from natural fibers such as hemp or flax using seamless weaving . The tightness of the fabric was achieved by swelling the wet fibers. However, the natural fibers only had a limited shelf life, as they could get moldy, for example, and always had to be dried immediately after use, for example in a hose tower . In addition, they were stiff after use and could only be rolled normally again after drying. Later attempts were made to seal the hoses by painting the inside or pouring tar, but this had the disadvantage that the hoses could stick. It was only through the use of Buna (synthetic rubber) that this could be avoided. Modern hoses are woven from hard-wearing synthetic fiber fabric ( polyester ), which is sealed by an additional inner rubber coating.
Pressure hoses-HD
High pressure hoses are only required when high pressure pumps are used. While pressure hoses are usually designed for a working pressure of around 10 bar, high pressure hoses, also known as HP hoses , are designed for a pressure of up to 40 bar. In addition to being designed as a folded hose, they are usually also designed to be dimensionally stable and thus rolled up on a rapid attack device. Because of the particularly high pressure, the couplings of the HP hoses must be made of brass, as aluminum is not suitable for the forces that arise. Like high-pressure pumps, high-pressure hoses are correspondingly more widespread in Austria than in Germany.
Pressure hose-S
The pressure hose-S is a dimensionally stable pressure hose in diameters 19, 25 and 33 mm for rapid attack devices on fire engines . It is wound onto a special, permanently mounted reel that is firmly connected to the vehicle's pump. Due to the dimensional stability, water can also be conveyed through the hose that has not yet been completely unrolled. Today, hoses with a length of 30 meters are usually rolled up on the reels. Other lengths (up to 90 m) are possible.
Pressure hose-W
Like the pressure hose-S, the pressure hose-W is a dimensionally stable pressure hose, but it is used for wall hydrants and is a little lighter and less durable.
Suction hoses
In contrast to pressure hoses, suction hoses are dimensionally stable so that they do not contract due to the negative pressure that occurs during the suction process. They are connected as a suction line to the suction inlet of a fire extinguishing centrifugal pump and closed with a suction strainer to remove water from open bodies of water, extinguishing water containers or collapsible containers .
It is forbidden to connect suction hoses to post hydrants.
| size | Diameter [mm] |
Standardized length [m] |
comment |
|---|---|---|---|
| A. | 110 | 1.6 or 2.5 | |
| B. | 75 | 1.585 | |
| C. | 52 | 1,580 | |
| D. | 25th | - | D suction hose:
|
Historical
The first fire hoses were used in ancient Greece under Alexander the Great . However, they were later forgotten. In 1558 there were first mentions of leather hoses in Augsburg , and in 1609 the first riveted hoses in Jena. It was not until the Dutch painter and fire chief Jan van der Heyden , who made a hose out of canvas , that the fire hose became widespread from 1673 onwards. This is where the name Holländer for the old hose couplings comes from . The inventor of the seamlessly woven hoses is unknown, but there is evidence of the weaver Johann Christoph Beck , who first made hemp seamlessly woven hoses around 1720. In 1781, Duke Karl August von Sachsen-Weimar had seamless hoses woven, which became tight due to their swellability.
The first rubberized hose was presented in 1865 at the German Fire Brigade Day in Leipzig . From 1809 to 1870, riveted leather hoses were also used. Nonetheless, non-rubberized hemp hoses were used in the smaller fire departments well into the 20th century.
Since the maintenance costs, which had required the care of the leather hoses, were eliminated (these had to be rubbed with grease after each use in order to remain supple), the leather hoses were soon replaced by the much cheaper hemp hoses. In particular, multiple rubber-coated and reinforced natural fiber hoses were superior to the susceptible leather hoses.
See also
- Extinguishing water supply
- Extinguishing water pumping over long distances
- Water-bearing fittings in fire protection
- Hose trolley (fire brigade)
literature
- Matthias Bartsch: Die Roten Hefte, Heft 224 - Use of pressure hoses . 1st edition. Kohlhammer, Stuttgart 2013, ISBN 978-3-17-022947-1 .
- Lothar Schott, Manfred Ritter: Fire Brigade Basic Course FwDV 2 . 20th edition. Wenzel-Verlag, Marburg 2018, ISBN 978-3-88293-220-1 .
Web links
- Free pressure loss calculation program for fire hoses
- Overview of fire brigade couplings, from then until today, from all over the world
- vfdb - Technical Report Compressed Air Foam ( DLS) - Behavior of fire hoses under pressure and heat (PDF; 1.6 MB)
- A video about hose production
Individual evidence
- ^ Stuttgart fire brigade: New roll-off container for the fire brigades in Baden-Württemberg
- ↑ Size F pressure hoses ( Memento from April 24, 2014 in the Internet Archive )
- ^ Lutz Rieck: Die Rote Hefte, Heft 27a - The extinguishing water supply Part I, The central water supply . 4th edition. Kohlhammer, Stuttgart 2000, ISBN 3-17-015011-1 , p. 61 .
- ↑ DIN EN ISO 14557
- ↑ Hose workshop of the Halle an der Saale fire department accessed on November 2, 2017
- ^ Sutton, Peter C. Jan van der Heyden 1637–1712. New York: Yale University Press, 2006. Print.
- ↑ Bruno Thommen: Die Basler Feuerwehr , 1982, p. 22, ISBN 978-3-0348-6707-8 Online
- ^ The sixth German Fire Brigade Day in Leipzig, August 19-22 , 1865 ; 1865; Hirth, Georg; pp. 12
- ↑ As an example: The Erlabrunn fire brigade: History of the Erlabrunn volunteer fire brigade in Saxony, accessed on November 2, 2017
- ^ Fornell, David P. Fire Stream Management Handbook. Saddle Brook, NJ: Fire Engineering, 1991. Print.