Sprinkler Services

Watermist Services

Nozzle Testing

Protect your assets the right way

Water mist systems are becoming increasingly popular for the protection of property, assets and people against the risks of fire. Regular testing of watermist nozzles ensures a system will continue to do its job in the event of a fire.

The FPA is passionate about improving and maintaining fire protection standards. We build long standing partnerships with our clients to offer them the help and support they need when it comes to fire protection. Whether you are an onsite maintenance manager or contractor, we will work with you to ensure the water mist nozzles are tested to the very best standard.

Our purpose built fire research and testing unit has the capability to undertake water mist nozzle testing for industrial and commercial premises, in accordance with BS 8489-1:2016 Fixed fire protection systems. Industrial and commercial watermist systems. Code of practice for design and installation.

The legislation from BS 8489-1 (part 11.4.5) states:

"Twenty nozzles, or 1%, whichever is greater, should be removed from various parts of the system. The removed nozzles should be tested in accordance with Annex D.”[…] “The checks and inspections recommended in to should be made at intervals of not more than 3 years

Why choose the FPA:

  • a truly independent third party and will provide impartial advice and reporting
  • experienced and specially trained engineers/staff 
  • we are recommended by insurers
  • We provide you with detailed reporting
  • Our testing offers fast turnaround times


How often should commercial and industrial nozzles be tested?

In accordance with BS 8489-1, commercial and industrial water mist nozzles should be tested every three years.

How do we test the nozzles?

The FPA offers the following test programme

  • visual inspection of all supplied samples to determine their general condition
  • a minimum of 75% of the heads will be subjected to a ‘function test’ to assess their general operation, with half being tested at the maximum operating pressure and the other half at the minimum (or standing system) pressure.
  • based on the findings of the visual inspection, the remaining heads will be subjected to either an operating temperature test in a water bath or additional function testing.
  • all heads will be subjected to a k-factor test. The quantity of water passed through the head at the maximum and minimum operating pressure will be used to identify any changes to the nozzles k-factor.

What is included in the report?

A technical report will be produced detailing the results of all testing, highlighting any non-conformities, noting any relevant regulatory guidance, including photographs of all samples received and identified points of interest.

Who can remove the nozzles?

Only competent professionals such as contractors, installers and designers should remove the nozzles. This is because the water pressure for required for water mist systems is exceptionally high and could be a serious health and safety risk. 


"We regularly use the Fire Protection Association to evaluate the condition and operational performance of sprinkler heads, their service is both efficient and cost effective. The knowledge and experience of their technicians shows in the detailed report which receives great feedback from both our engineers and our clients"

Paul Berry

Sales Director, Johnson Controls, Fire Suppression UK & Ireland

What Do I Do Next?

To find out more about how we can assist you with any of our sprinkler services please either

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Enquiry Form

If you feel your company can benefit from our customised training solutions, please fill in the following form, or email sprinklers@thefpa.co.uk with your enquiry.



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