Hydrant and hosepipe system

Hydrant

According to NBR 13714 the definition of a fire hydrant is: ponto water inlets where there are one (single) or two (double) outlets containing angle valves with their respective adaptors, plugs, fire hoses and other accessories.

A fire hydrant is nothing more than a hydraulic system for fighting fires and protecting people and property. It consists of a water reservoir, fire pumps, hydraulic pipes and parts, a manoeuvring register, a hose shelter and a booster register. 

Together with sprinklers, they help fight and extinguish fires. Hydrants are manually operated and can be used by the residents themselves in case of emergency. Generally, in buildings, they are placed on the wall and the manager or other operator responsible for the equipment must have a hose switch, a nozzle nozzle, two 15-metre hose lengths each and the shelters that must be properly marked.

How to operate a hydrant

If a fire hydrant box has hose(s), fit them to the register, then open this register to supply water, the flow and pressure are determined in the fire fighting project. The user must be careful not to open or close a hydrant too quickly, as this can cause a "water hammer" , which can damage nearby pipes and equipment. 

When a firefighter is operating normally use individual protection equipment as gloves and a helmet. High pressure water flowing through a potentially aging and corroded hydrant can cause a failure, injuring the firefighter or people nearby.

We have noticed that around the hydrants you cannot stop vehicles or restrict their access inside the buildings with cabinets. The red colour is meant to indicate and facilitate its location, do not paint the hydrant box any other colour

Hydrant system reservoir 

Generally its location is in the upper part of the building, but if there is no possibility for it to stay there, it is accepted, provided that the reason is clarified to the Fire Department, that its location be in the lower part. 

The RTI (Technical Fire Reserve) must also be observed, which is the volume of water intended for cases of fire, the amount of which varies in each building. However, the minimum in a residential building is 4,200 litres and the larger the development is automatically the larger this reserve will also be.

The tanks must be fire-resistant for at least 4 hours and preferably made of reinforced concrete 20 cm thick. 

Pumps of a hydrant system

The pumps used shall be of the centrifugal type driven by electric motor or combustion engine.

Your system should have two pumps (one main and one backup) for pressurisation and be independent of the general electrical network.

Try to leave the pump automation panel on automatic and avoid the neutral point, so you won't need a fireman to perform the simple task of reversing the panel. And, if the general power switch of your building is turned off, it will not affect the pump system at all.

Nozzles

 These devices are for water discharge through hoses, and are adjustable, allowing the emission of compact jet or mist, or non-adjustable, allowing only the emission of compact jet.

Pipes

They must be able to resist the effect of heat while maintaining normal operation.  

 Thermoplastic materials, in the form of pipes and fittings, must only be used underground and outside the projection of the floor plan of the building, meeting all the requirements of resistance to internal pressure and mechanical stresses necessary for the operation of the installation. 

Generally, the most commonly used materials are copper, steel and PVC.

Leakage test

The system shall be tested under hydrostatic pressure equivalent to 1,5 times the maximum working pressure, or 1 500 kPa minimum, for 2 hours. No leaks in the system are tolerated. If leakage is observed, corrective action should be taken and the entire system retested as follows

 Operation

Measuring the pressure and flow at the most favourable and least favourable point of the hydrant.

  Maintenance plan

According to NBR 13714, the maintenance plan aims to ensure that:

a) all angle and quick-opening valves have been opened fully, normally and manually, and, when closed, the complete seal has been checked, ensuring the good condition of the valve body with regard to corrosion; 

b) all sectional control valves have been operated without any abnormality, including with regard to leaks in the body, bonnet or gaskets; 

c) all fire hoses have been inspected, maintained and stored in accordance with NBR 12779;

(d) all nozzles have been used and their manoeuvrability checked;

e) the physical integrity of the shelters has been ensured;

f) all the pipes are painted without any damage, including in relation to the supports used;

g) the signalling used at the hydrant and/or hose reel points is in accordance with the specifications;

(h) the pressure control devices used inside the pipes have been checked for effectiveness and function;

(i) the functioning of all installed instruments and meters has been checked;

j) all electrical interconnections have been inspected and cleaned, removing oxidation;

l) the motor/pump gaskets have been checked, adjusted or replaced, receiving adequate lubrication and other care, in accordance with the manufacturers' instructions; m) the control and alarm panel(s) have been fully inspected, attesting to their full functioning.