Fire hose

The fire hoses are pipes being used to transport the Eau in the hydraulic devices of Lutte against the fire.

They are flexible tubes provided with standardized connections. Certain countries use connections of the type Guillemin; other countries use connections of the type Storz or nipples.

One can install a division which makes it possible to supply several lances starting from one only pipe from the van.

The pipes big length are laid out on a reel, a drum on wheels provided with a handle making it possible to tractor draw it. There exist also reels turning into fixed on the vans of fire for the extinction of small fires, with a semi-rigid pipe (Lance of the reel turning or LDT, similar to a Robinet of fire armed).

The majority of the current pipes are said to “internal wall smoothes” (PIL); this one being rubber they presents less pressure loss that the traditional pipes. The external walls are either textile (Polyester S) or rubber.

The installation of the pipes and their connection is called the establishment.

Colors

Initially, the pipes were natural color of external material, in general gray or brown. They are now in general of a bright color to facilitate their vision the night or in undergrowth: red, orange or yellow.

Connections and diameters

In France

In France, the connections are of the symetric of type Guillemin, tight couplings with the hand or with a Hydrant key . The pipes most frequently used are:

pipes 110 mms in diameter (connection of ∅100 mm) to supply the machine-pump: flexible tube to connect the machine-pump to hydrant, semi-rigid to aspire since a water point;
flexible tubes 70 mms in diameter (connection of ∅65 mm): flexible tube to connect the machine-pump to division or a large lance, semi-rigid pipe to aspire with a motor-driven pump feeding of the lances;
flexible tubes 45 mms in diameter (connection of ∅40 mm): flexible tube to supply the lances, semi-rigid pipe to exhaust (for example to empty a flooded cellar) with a motor-driven pump;
semi-rigid pipes 22 mm in diameter for the Lance of the reel turning (LDT, used normally exclusively on small fires).

The large pipes (110 or 150 mm) can also be used for to feed from large lances, or for establishments over big lengths.

In Paris, the sappers firemen use pipes with the standardized diameter but the connections are of diameter 50 on the pipes of diameter 45 and 70

In Switzerland

In Switzerland, the connections are of the symetric couplings of type Storz. The standardized diameters are of ∅25, ∅40, ∅55, ∅75, ∅110, ∅125 and ∅150mm. One distinguishes:

pipe suction: rigid control in depression of the point of water to the pump (connection), also called “aspirau”, in general diameter of 110 mm or superior;
led food: control going of a pump, a tank or a cistern, with the Pump, in general diameter of 75 or 110 mm;
led transport: control of the hydrant (p. e.g. hydrant, pump) to a division, in general diameter of 75 mm;
pipe discharge: control of the hydrant (p. e.g. hydrant, pump, division) to a lance, diameter from 40 to 75 mm;
led of first intervention: semi-rigid control under normal pressure or high pressure assembled on a vehicle, intended above all for the first intervention, diameter from 25 to 40 mm, similar to the French Lance of the reel turning.

Arrangement and establishment of the pipes

There exist three modes of arrangement of the pipes, which imply manners of establishing different.

Rolled up pipes

In France

Conditioning in crown is the traditional conditioning of the flexible tubes of low diameter; in fact the pipes are connected to the lances.

The flexible tubes are folded into two in their medium then rolled, the half-connections towards outside. To unroll them, one launches them while holding the half-connections, they thus form U which constitutes the reserve length necessary to advance in the case the last length (that on which the lance is fixed).

The establishment is made necessarily back with fire. It is thus necessary to go up to the point of establishment (to security zone, but sufficiently near to the disaster) and to unroll the pipes while progressing towards the food.

In Switzerland

In Switzerland, the establishment is always done in direction of fire. The pipes are generally rolled without being folded, a half-connection inside and the other outside. To unroll them, one launches them while holding only the external half-connection.

It is the case mainly when the establishment of attack is carried out only starting from pipes in échevau, those rolled up being used only to lengthen or feed.

Pipes on reel

The pipes of large diameter, 70 mm in France, which are used to connect division (supplying several lances) to the van, are conditioned on a travelling reel (gone up on wheels); the division already connected to the pipe. The pipe is simply rolled around the drum.

The reel is brought by the binomial of food to the point, division is posed on the ground, then the reel is brought back towards the machine-pump, the progressively being held pipe. Once arrived at the van, the pipe is still unrolled to the following half-connection, and this one is connected on the outlet side of pump. It is the reverse in Switzerland, any establishment being done on the basis of the pump.

Certain vans have a semi-rigid pipe of small diameter, 22 mm in France, rolled up on a fixed reel. These pipes are not crushed, with the result that they can be used even without being completely unrolled; the implementation is thus particularly fast. The diameter is necessarily limited if one wants to store a sufficiently large length in a restricted volume; so they have a limited flow, about 150 L/min, and are thus adapted only to small fires of outside. One calls them lance on reel turning to France and led of fast attack or of first intervention in Switzerland.

Certain machine-pump have pipes of 45 mm pre-assembled on a reel turning, for an establishment directly since the van. They are thus unrolled up to the point of establishment by the chief of binomial of attack; serving as the binomial brings the first connection to the point of establishment, which constitutes the reserve out of U, then the driver of the van still unrolls the pipe to have access to the following half-connection, which it demolishes and connects on the outlet side of the pump.

Pipes in hank

In certain machine-pump, discharge pipes are conditioned in hank (folded and not rolled) in cases. The case is brought up to the point of establishment, the half-connection is posed and maintained by the chief of the binomial of attack, then serving it car the case towards division or the van, the being established pipe (unfolding itself) progressively.

The pipes in hank also make it possible to make an establishment while progressing towards fire, but it is then necessary to prevent by radio operator the machinist of the van when the setting in water of the device is possible. It is the case in Switzerland, where these cases are called “hoods”, and contain approximately 70 m of pipes of 55, for a weight of 45 kg. They are carried to the back, which prevents their carrier from being equipped with a Breathing apparatus insulating. It is the average privileged person by certain bodies for the establishment of a discharge pipe. The last years saw appearing cases of more reduced size, containing about thirty meters of pipes and transportable to the hand.

It also happens that the cases are left far from fire and that the binomial of attack unfolds them by drawing the pipe towards fire. This makes it possible the carrier of the case not too much to be exposed, or, when these cases are left in the vehicle, to do without carrier. It is the case for example in certain airports, where only one man is enough to establish a control, this one being put out of water automatically as soon as the pipe is entirely unfolded.

Establishment on the public highway

For the important device comprising several lances, even divisions, it matters that the pipes feeding divisions are well ordered. If they are on the roadway, they must skirt the pavement; if they must cross the roadway, they must cross it with right angle and be protected by a device from crossing.

Calculation of the pressure losses

The pressure losses indicate the reduction in the Pression at the end of the lance compared to the exit of the pump. These pressure losses are due to friction in the pipe. Let us note that by simplification, the firemen include the variation of pressure with altitude in the pressure losses, whereas this phenomenon takes place also with constant load; it would be to better speak about “loss of pressure”.

This loss of pressure is a capital problem because the pressure in end of lance determines the use of the lance (distance from projection, atomizing of the jet…). For example, one needs approximately 6 bars at exit of a lance for adjustable mixed flow. The driver of the truck must adjust the power of the pump in order to provide the good pressure to the lance.

To reduce the pressure losses, it is necessary:

to use a pipe with smooth internal wall (PIL);
to avoid the elbows and torsions;
to use pipes of large diameter; the difficulty of the weight and the volume of water being used arises then to fill the pipe itself (dead volume).
to add to the water of the specific additives to modify its rheological properties (these additives being in general polluting and expensive, only the brigades specialized in the fires of skyscraper use them for the moment)

When one has which it, it is to better use rigid pipes (type Colonne dries).

For a given pipe, the loss of pressure is:

proportional to the length;
proportional to the square of the flow (if the flow is doubled, one multiplies by four the pressure losses);
proportional to the uneven one: one loses a bar every 10 m of upwards uneven, one gains a bar downwards every 10 m.

As example, for 100 m of pipe (hectometric loss of pressure):

for a pipe of 70 with a flow of 500 l/min, one loses approximately 0,55 bar;
for a pipe of 45 with a flow of 250 l/min, one loses approximately 1,5 bar;
for a dry column, one loses approximately 0,3 bar by stage (made uneven and friction included/understood, the flow is not mentioned in the source).

See too

External bonds

general Walk of the operations: pipes, site of the firemen of Saint-Louis (Haut-Rhin)
Summary table of the flows and pressure losses (file Microsoft Word compress with the format Zip), SP-Var.com
Some pipes proposed by the Swiss firm Vogt

Internal bonds

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