Wet Riser Servicing

What Does Wet Riser Servicing Involve And Why Is It Crucial?

Wet Riser Servicing is crucial for wet risers which are an essential component of any high rise building or a commercial property’s fire protection system. They are legally required to be installed when a building is more than 50m high. These vertical pipes are designed to deliver water to all floors of the building, enabling firefighters to extinguish a fire quickly and efficiently without having to drag charged fire hoses all the way up into the building, unlike dry risers. However, like any other fire product, wet riser servicing is needed and regular maintenance to ensure that they are in good working order.


What does wet riser servicing involve and why is it crucial?

The service of a wet riser involves a series of checks, tests and maintenance procedures that are carried out by a qualified engineer to ensure that the system is in good working order. British Standards – BS 9990 recommends an inspection of inlets, landing valves and value enclosures should be inspected every six months, to ensure the system is ready for use. One month during the year, an engineer will undertake a wet test, this will be the 1st service and then 6 months later, the 2nd service will be carried out which is initially just a visual inspection. Signage as required should also be checked.

The maintenance of wet riser systems is under the responsibility of the property owner. If the system fails in the events of a fire, not only will this result in the property being damaged but it can lead to injuries or even the loss of lives. The property owner will be held liable for any casualties and could then be prosecuted. Thinking back to the Grenfell Tower tragedy, in reports following the fire, Head of Fire Safety at the Arup Group noted that “water supplies to firefighters failed during the blaze because the main riser pipe system was out of date”. This is why frequent inspection and maintenance of a wet riser system is crucial!

The following steps below explain the procedures in the maintenance of a wet riser.

  1. Visual Inspection – The engineer will carry out a visual inspection of the wet riser to check for any obvious signs of wear and tear, or damage. They will also check the valves, joints, and other components for signs of corrosion or leaks.
  2. Pressure Test – A pressure test is taken to ensure that the wet riser system can withstand the pressure required to deliver water to all floors of the building. This is done by increasing the pressure, which should be completed by using the systems pump for 15 minutes. During this test, a visual inspection should also be undertaken to check for any leaks or other issues.
  3. Flow Test – After a pressure test is taken, a flow test is then carried out to ensure that the water supply to the wet riser is adequate. This test involves opening the valve on the wet riser and measuring the flow of water to each outlet on the floors of the building. If the flow is not sufficient, the engineer will investigate the cause and take the necessary steps to rectify the issue. A flow test is measured in litres per minute.
  4. Drain Down – This is essentially where the wet riser gets drained down and flushed to remove any debris or sediment that may have accumulated in the pipes of the wet riser.
  5. Certification – Once the service is complete, the engineer will issue a certificate to show the information needed to confirm that the wet riser has been serviced, as well as the next service date.