Wet Riser Maintenance
Wet Riser maintenance is essential, in the event of an emergency it is paramount that the system works. After all it was designed for one purpose, to assist the fire brigade. Enabling them to effectively fight a fire in high rise buildings.
If your building is over 50 metres in height chances are you have a wet riser. Quite possibly you’ve often wondered what are those cabinets that say ‘wet riser outlet’ and what do they do.
WHAT DO WET RISERS DO?
Wet risers are very similar to dry risers. The main difference is that a wet riser is constantly full of water to allow the fire services instant access to a water supply in the event of an emergency. So it is very important to keep these systems up to date and well maintained. Wet risers need to be visually inspected every six month and a more in depth inspection required annually.
HOW DO WET RISERS WORK?
Wet risers are constantly linked to a pressurised water system, fed by ‘fire pumps’ usually located within the basement area of a building. Those fire pumps are also linked to a water tank, these two combined give you your pressure and water supply. So in the event that a fire broke out in your building and an outlet valve was opened the pumps would start and give you the desired pressure and flow.
WHATS INVOLVED IN WET RISER MAINTENANCE?
- Make sure the pumps are running correctly and the incoming water supply is healthy.
- Inspect each floor for leaks, damage to pipework, valves or fittings.
- Ensure pressure of each PRV landing valve is correct.
- Flow test on the top two floors.
- Check all isolation valves are open and operational.
HOW DO YOU CARRY OUT A FLOW TEST ON A WET RISER?
As our picture shows you have two pipes within the cabinet or housing of a wet riser. One is the wet riser and the other is a test drain, the purpose of a test drain is to allow for either flow tests or maintenance should you need to drain down the wet riser system. When carrying out a ‘flow test you link the two together with a short length of fire hose and a flow meter and open the wet riser landing valve. The fire pumps will then start to work and give you your required flow and pressure at around 1500 litres a minute.
