How to test your water pressure & flow rate

When considering an irrigation system fro your garden or allotments. The first thing you need to know is:

• Do I have enough water

• Do I have the right flow of water 

• Do I have enough pressure 

Here are some tips for testing you water pressure and flow rates. ​

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Pressure

Pressure is an important part of any irrigation system. Most irrigation emitters have a optimum pressure for operation or an operating pressure range. with the wrong pressure, an irrigation system will not operate correctly. 

There are 2 ways to measure the pressure at you connection. 

• Static Pressure 

• Operational Pressure

For this test it is important to measure the operational pressure . This is the pressure when water is flowing. 

The Water can be tested by installing a pressure gauge near to the point of extraction. Measure the pressure in Bar, as most of the data for UK products are in this measurement. 

while the water is flowing you are looking for a minimum of 1.5 bar for most irrigation systems/ equipment. 

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Flow Rate

The flow rate will determine how big or how many section you can have in your irrigation system. 

All emitters have a working flow rate which determines how much water you can apply and, with sprinklers, how far the water can be thrown. 

Using a 10ltr bucket and a stop watch.

• Time how long it takes to fill 10 liters. 

For UK products you are looking to know in the measurement in l/hr (liter per hour) or m3/hr (cubic meter per hour). A good flow rate is consider to be above 1.5 m3/hr (1500 l/hr).

to get to this:

• Divide 10 liters by the amount of seconds it took to fill the bucket 

• Times this by 60 will give you l/sec

• Times the l/Sec b 60 = l/hr

• divided by 1000 = m3/hr

example

• 10 ltr / 12 seconds = 0.833 (l/sec)

• 0.833 (l/sec) x 60 = 50 (l/min)

• 50 (l/min) x 60 = 3,000 (L/hr)

• 3,000 (L/hr) / 1,000 = 3 m3/hr

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