How To Select A Pump For A Fire Fighting System?

Fire fighting pump is relevant when talking about fire safety. It is due to these pumps that pressurized water is delivered on time and the flames are suffocated without any harm to life and assests. 

Nevertheless, in order to be effective, the given process has to be carried out by the adequate pump. so, there are certain ways in which it should be done. that have to be taken into account when choosing a water pump for fire fighting. 

Thus, it is crucial to consider the design of a water pump that meets your requirements regarding pressure flow rate. The article in question serves as a guideline that is supposed to help choose the pump that fits one’s needs.

Pump In The Firefighting System And Its Working

In a firefighting system, the pump is a device responsible for bringing the water to the required pressure to put out fires. Most often, it is operated by electric motors or diesel engines, drawing water from a resource, such as a reservoir or hydrant. 

Suction, pressurization, and discharge are the basic terms to describe how the water passes through the pump to reach the firefighting equipment.  Controlled mechanisms are used to support proper functioning and maintenance of the required pressure and flow rate.

Understanding Fire Pump Types

Centrifugal Pumps

Centrifugal pumps are one of the most well-known pumps due to their reliability and robustness. These pumps work with the help of an impeller to produce force. This causes the flow and pressure of water to increase and pass through the pump into the system. 

They are mostly used in large-scale projects as they are able to provide high flow rates. Centrifugal pumps can adapt to various sources of fuel, too and are really easy to maintain.

Positive Displacement Pumps

Positive displacement pumps, such as gear pumps, vane pumps and piston pumps, are another option for firefighting systems. These pumps deliver a constant flow rate regardless of pressure changes. This is done by trapping a certain quantity of water, which is then thrown out with a lot of pressure. 

This makes them ideal for situations where precise and pressurized water delivery is required. However, they are generally more expensive and require more maintenance than centrifugal pumps.

Axial Flow Pumps

Axial flow pumps are very different from the other two pumps. They operate differently with the help of propellers that are identical to blades. This system in pumps provides a high flow rate along with rapid movement of water.

These pumps can be highly efficient in open bodies of water or large-scale firefighting operations. However, they’re less suitable for high-pressure fire protection systems compared to centrifugal or positive displacement pumps.

How To Select A Fire Pump: A Step-By-Step Guide

Selecting a fire pump is a crucial step in ensuring the effectiveness of a fire protection system. Here’s a detailed step-by-step guide to help you make the right choice:

Step 1: Hydraulic Calculations

Hydraulic calculations have to be made before selecting a suitable fire pump to determine the water flow and pressure required for a particular application. Such calculations are based on the building’s size and number of stories, type of occupancy, hazard classification, and minimum required fire protection coverage. 

In other words, the calculated or specified flow and the calculated pressure present the objective of different firefighter’s hydraulic calculations. 

Step 2: Suction Pressure Calculation

Calculate the suction pressure needed to be provided to the fire pump. This pressure is impacted by different aspects, like the elevation of sources and the amount of friction in the pipes. It can also be affected by the amount of variation in the atmospheric pressure. 

Determining the suction pressure makes sure the pump receives enough water to supply firefighting regardless of the source of pressure and flow.

Step 3: Select a Fire Pump Model

Choose a fire pump model according to the hydraulic calculations and suction pressure of the needed one based on these calculations. In addition, it is important to ensure that the flow demand of the protection system is as low as 150, less than the flow demand of the pump. 

The provided specifications should include the type of the power source, such as a diesel engine or electric motor, as well as the information on its compliance to a certain industry standard, say, NFPA 20.

Step 4: Determine Net Pressure

The net pressure required at the fire pump discharge is calculated to accommodate the friction losses in the piping network. it is also done to pump the water to the fire sprinkler system or standpipe system. 

The pressure determined as net accounts for the losses occurring due to the pipe friction, fittings, valves, and elevation from the fire pump to the point of discharge of the system. In this way, the net pressure will be enough to pump water at the required flow rate and pressure throughout the system.  

Step 5: Add Suction Pressure

Having found the net pressure, it should be added with the calculated suction pressure to sum up the total discharge pressure that the fire pump requires to supply. Basically, the total discharge pressure consists of the suction pressure required to pull out water into the pump and the net pressure that is needed to transport water to the system.

Step 6: Testing Time

After choosing the fire pump, the next step is to perform comprehensive testing. This can be accomplished by running the pump in numerous operating modes to achieve the expected pump flow, head delivery, and reliability that are consistent with the final purposes. 

In addition, if the pump demonstrates a higher discharge pressure or the same as the system, the device may be used, and serviceability is guaranteed, but if it fails, the best option would be to choose a different pump.

Factors to Consider When Selecting a Fire Pump

• • Flow Rate and Pressure Requirements

   The initial stage in the process of choosing a fire pump is determining the flow rate and required pressure. A dependable calculation of these parameters is based on the size of the facility, particular fire risks present on the site, and national standards and                                   recommendations. 

  To guarantee that the fire safety system will be effective, one should consult with a local fire safety organisation to understand the correct indicator values. 

• • Water Supply

   Consider the water supply available for your firefighting system. Is it a municipal water supply, a storage tank, or a natural water source? The type and location of your water supply will influence the pump’s specifications, such as its suction lift capability and the          need for priming.

• • Power Source

  Major types of power available to run fire pumps are electric power, diesel power, and steam power. Select the appropriate power that  is available at your site and compatible with your selection of pumps. The availability of a reliable source of electric power will govern the choice of a fire pump.

• • Materials and Construction

  The materials and construction of your fire pump should suit the application and the environment. For example, choose a pump with  materials and coatings that can withstand exposure to corrosive or extremely hot or cold liquids. This will secure long-term reliability        and durability and save you money.

Conclusion

Selecting the correct pump for your firefighting system is not a decision you make every day and is indeed of critical importance. By understanding the various types of pumps available and the different types of functions they perform, you may make the right judgement. 

It is to your benefit as you will ensure the effectiveness and viability of your firefighting system. And finally, remember to consult with fire safety professionals if your judgment seems to be too hard.