Fire hydrant: the device and the principle of operation. What is the purpose of the fire hydrant?

A fire hydrant is equipment that provides convenient intake of liquid from a water supply network. Its main application is as a point of connection of fire hoses used for filling a fire truck's cistern or for extinguishing a fire. Also this device is very often used for reclamation works. In the article below, you can find out what the fire hydrant is, the device and the principle of operation.

Types of fire hydrants

Devices of this type, which are used in suburban areas most often, can be of the following types:

• Above-ground (bezkolodeznye).
• Fire hydrant underground (device in the well).

The last option is the most in demand. This is due to the fact that the fire will ensure uninterrupted water supply.

Underground hydrant

The fire hydrant device in the well is implemented as follows:

• The hydrant must be installed in such a way that a faucet is visible on the surface. Such a device is manufactured in accordance with GOST. The hydrant can be of various shapes and sizes.
• Equipment of this type, as a rule, is used if there is a liquid with a temperature of 5 to 50ºC in the cold water supply system. Use hydrant at minus temperature is not possible. The water pressure should not be more than 10 MPa.
• The device of the hydrant and the fire column in the well must be made only in an upright position.
• Special equipment is provided for this equipment. Before installation, the hydrant must be rinsed with well water. The height of the unit can be with an interval of 250-1250-3500 mm.
• With these dimensions, the valve opens at 24-30 mm. The design of hydrants provides holes for connecting hoses.
• When using hydrants, very often a fire line is built along the perimeter of the well. It includes numerous plastic pipelines or hoses laid along the perimeter of strategic facilities.
• To install a fire hydrant of any type, there is a specific instruction. It shows how to make a fire hydrant device, its connection diagram and the sequence of actions during installation.

What should be a well

As a rule, the detailing of the well with the hydrant is performed by professionals. However, if you know the specific requirements for using this type of equipment, you can build a well yourself.

• The well should not be located at great depths. The water supply must be from the well. In this case, water does not need to be cleaned of impurities, the main thing is that it does not have stones.
• The width of the well should not be less than 800 mm. Such parameters allow unhindered switching on and off of the equipment.
• The well is made of plastic pipelines of large diameter and reinforced concrete rings. It is not recommended to lower the equipment into a dug and unfinished well, as with a small displacement of the ground it can simply fall asleep.

Overhead hydrant

A fireless fire hydrant (the device and the principle of operation are discussed below), in comparison with an underground installation, is a more complex construction. Such units can be found in any terrain, they are installed on a special hatch or surface of the ground. A prerequisite is the presence of a source of water in the immediate vicinity.

In winter such equipment is very important to completely free from water. Otherwise it will freeze and it will not be possible to use it.

Also these devices are equipped with additional functions. Overhead hydrants, as a rule, are equipped with an automatic start or release from water.

Mounting Tips

• The height of this device can be different and when choosing it, it is necessary to take into account the depth of freezing. On the fire hydrant, a column is screwed, complete with two nozzles, providing, if necessary, uninterrupted supply of water.
• There are modern models, which additionally provide for automatic drainage of water as a result of using a fire hydrant.
• The operational life of this equipment is approximately 50 years. Thanks to innovations in production technologies, these devices can also be used outside. For this, there are special devices. It should also be noted that installing a fire hydrant (device on the pipeline), it is very important to take into account the degree of freezing of the ground.
• The design of this unit provides several taps for connecting hoses. They can work either individually or in parallel.

Installation requirements

The most important aspect, which should be paid attention during installation, is the location of the hydrant. The following requirements are imposed on him:

• Fire hydrant (the device and the principle of operation below) may be located on the road and at a distance from it not more than 2.5 meters.
• Installation should be carried out at a distance from the nearest building of 50-100 meters.
• It is forbidden to install the hydrant at a distance of less than 5 meters from the wall of the nearest building.
• It is forbidden to install this equipment on the branching of pipelines.
• In addition, the distance from the wall of the manhole to the axis of the riser can not be less than 175 mm, and from the end of the riser to the hatch cover - 150-400 mm.

Purpose, the device of a fire hydrant

A fire hydrant is, first of all, a guarantee of fire safety. Established in a timely and in the right place, the hydrant will ensure unhindered access of the population and firefighters to the water in the event of emergencies. For this reason, the design of these units should imply a competent choice of location, and also fully meet the state-established requirements and standards.

Fire hydrant: the device and the principle of operation

This equipment is a water tap, the design of which provides three main parts: a mounting head, a valve head and a riser. Depending on the hydrant model, the dimensions of these parts vary. Also, on the type of this equipment, it is possible to have a stand for above-ground models, or a ground well, into which the unit is installed.

The hydrant is activated by means of a special key, which rotates the rod. In turn, the rod actuates the valve and thereby opens access to water. The device of this type is able to function not only as a make-up for fire engines, but also as an independent source of water.

The order of work

From the type of fire hydrant - underground or above ground - depends on its installation, either it starts from the well, or from the mount of the stand, respectively. After preparing the surface for the unit or preparing a shelter for the thread of the pipeline, previously supplied to the water supply system, a fire column is installed. Also during the installation, the hydrant elements are treated with waterproofing and anticorrosive compounds that extend the operational life of the equipment.

Maintenance of working capacity

To ensure regular availability of the unit, it is necessary to carry out its technical and service maintenance twice a year. The list of works to be completed includes:

• Ease of turning the valve.
• Sealing and integrity of the valve and gaskets.
• The presence of water in the well of rain or leaked from the hydrant.
• Checking the working elements of the device for the presence of a nipple, the integrity of the rod, lid, body, thread, as well as the presence of cracks and other damage.
• Check for tightness and integrity of the manhole.