You may be wondering exactly what a ‘dry riser’ is. A dry riser is, in fact, simply a set of permanently installed pipework (water inlets, pipes, and outlets) spread through a building on all levels and which firefighters can access to help them fight a fire on an upper floor of a building. An air valve is fitted at the top of the pipework so that air can be released when the system is full of water. Fire-resisting enclosures surround the pipework.
It is called a dry riser because it should always remain empty and only be filled with water during an actual fire or when being tested.
Having a fixed water distribution system, such as a dry riser, allows firefighters to get much bigger quantities of water to the upper reaches of a building in a short space of time. This is obviously a huge help in an emergency fire situation and prevents firefighters from having to lug long and heavy hoses up the stairs and through the various landings of a building.
Firefighters access the dry riser via the fire hose water inlet valve on the ground. They can then pump water up the dry galvanised steel piping to landing valves (outlets) at particular locations around the building. Each floor will have its own dry riser cabinet. You will also find dry risers in the basements of large buildings or even in underground car parks.
Dry risers are particularly useful for buildings which are at least 18 metres high. This includes many multi-storey flats and other high-rise buildings.
Dry risers vs wet risers
A dry riser differs from a wet riser in that the former doesn’t have its own dedicated water supply. The wet riser has an automatic system to pump water at the high pressures necessary. That’s because these tend to be installed in buildings which are more than 50 metres high. You will also find them in tall buildings where there isn’t enough space for a fire engine to get close enough.
Maintenance of a dry riser
It’s important to inspect a dry riser (and a wet riser) every six months and test it annually to ensure that if an emergency occurs, it will perform well. The annual test involves pressure testing the pipes by running water through the system for at least 15 minutes.
This is a long enough time to check whether or not there are any leaks, blockages or other faults which could hamper its performance. The checks are in line with fire safety regulations set out in BS9990. These checks allow firefighters to detect any previous vandalism to the pipes, equipment or the building itself which could prevent the water reaching its destination quickly – if at all. In doing so, they can then make the necessary repairs.
@BAFEFIRE: “If your building has a dry riser or wet riser in place BAFE strongly recommends using an appropriately third-party certificate provider for your service and maintenance requirements. It is a legal requirement to ensure these provisions are maintained appropriately, so it remains ready and effective in an event of a fire.”
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