Water Flow Rate Explained

What is water flow rate?

This is the amount of water running through a pipe and eventually out of a tap or other outlet over a given period of time. It is usually measured in litres per minute (lpm).

A flow rate of between 10 and 15 lpm would be considered average for a domestic property. Below 10 lpm would be an indication of low water pressure, a figure of 15 lpm or above would be considered a very good flow.

The flow through a pipe depends on the pressure applied at the source, the length of the pipe and internal pipe diameter. The surface characteristics of the pipe and the number and shape of any bends can also have an influence on the flow rate.

The graph below has been generated from calculations assuming the pipe is in good condition and in a straight line.

As shown in the chart, there is a relationship between water pressure (the force at which water is pushed through a pipe), and the flow rate (the volume of water running through the pipe).

It is important that we have a basic understanding of flow as we can use this when calculating what thresholds to set in our flow based leak detectors.  There are two main settings that are affected by flow; the volume and the time parameters.  It is important that we try to set them with some  accuracy as this will affect how much water will escape should there be a leak.

You can find out more about our full range of water leak detection systems here.