What are they and why are they required for fire sprinkler systems?
A priority demand valve is an electrical valve which restricts water flowing to your property in the event of a fire, allowing 100% of the available water to feed the fire sprinkler system.
Why do you need one?
BS9251 requires a water supply to provide enough water to meet the requirements of the fire sprinkler system in an event of a fire. If your property is using a shared supply (supplying both your property domestic water and your fire sprinkler system), BS9251 – 188.8.131.52 requires your water supply to be capable of providing the flow rate determined by 5.3.3 plus at
least 25 L/min (for your domestic requirements).
If your water supply is not capable of providing this, but meets the requirements of 5.3.3 you will require a priority demand valve.
How do priority demand valves work?
A priority demand valve is held in the open position allowing water to flow to your property. The valve will automatically close, isolating the supply to your property in the event of a fire which has activated your fire sprinklers or smoke alarm or a power failure.
Who installs the priority demand valve?
The fire commissioning engineer will test your flow at the commissioning stage and if required install a priority demand valve into your domestic system normally after your domestic stop tap.
If you have any questions regarding priority demand valves or anything else, please contact our office on 01267 468090 or discuss it with our commissioning engineer when they attend your site.