What Does Wet Riser Mean In Construction?

What Does Wet Riser Mean In Construction?

A wet riser is a system of pipes and valves running through the inside of a building that are permanently filled with water.

This type of riser is typically installed in buildings over 50 meters tall, as higher pumping pressure is needed to charge the riser than that can be provided by fire service’s equipment.

Wet risers are designed to supply 1500 litres per minute for 45 minutes as a minimum.

In contrast, dry risers are empty pipes running up the inside of a building, with input connections on the outside or fire escapes.

They allow fire rescue services to pump water through the building before use. Dry risers are required in buildings over 18 meters tall, where there is an excessive distance between entrances and the upper floors.

Regular maintenance and inspections are important for both wet and dry risers to ensure normal operation and avoid unexpected malfunction in case of fire.

Fire safety signs on dry and wet risers are essential to protecting lives and complying with regulations.

How To Install A Wet Riser?

Installation of a wet riser is required in buildings over 50 metres high. A wet riser is a supply system intended to distribute water to multiple levels or areas of a building, and is kept permanently charged with water from either a storage tank or the town’s main water supply.

The pipe system is connected to a permanent water supply and has landing valves at each floor, with pressure regulated outlets at around 8 bar.

Wet risers are designed to supply 1500 litres per minute for 45 minutes as a minimum.

Dry risers are vertical mains fitted into staircase enclosures or other suitable positions, with outlet valves on each floor and inlets fitted at ground level to enable the fire brigade to connect to.

When Should A Wet Riser Be Installed?

A wet riser should be installed in buildings that are 50 meters or higher. This is because the excessive pressures required to pump water to high levels make it difficult to provide a suitable breeching inlet position for a dry riser.

Wet risers are designed to supply 1500 litres per minute for 45 minutes as a minimum, and must maintain a minimum running pressure at top outlet at roof level of 4 bar at a flow rate of 22.7l/s.

In addition, wet risers should be inspected and tested regularly, with visual inspections every 6 months and servicing annually.

How Does A Wet Riser System Work?

A wet riser system is a fixed installation of water-supplied pipes on the premises of a building that are permanently charged with water.

This system is used to provide immediate access to water supply during fire-related emergencies, especially in buildings over 50 meters tall where higher pumping pressure is needed.

The wet riser system consists of vertical pipes with landing valves at each floor except the ground, connected to a permanent water supply such as a storage tank.

The tanks are fitted with an automatic warning system to indicate a low water level and should be capable of maintaining a minimum running pressure at top outlet at roof level of 4 bar at a flow rate of 22.7l/s.

Wet risers should be inspected and tested regularly and should be within fire-fighting shafts or protected lobbies, stairs or enclosures where necessary.

What Are The Advantages Of Wet Riser System?

The main advantage of a wet riser system is that it provides more reliable and effective pressure in taller buildings, allowing firefighters to effectively move water to the areas that need it.

This is because the pipes are permanently filled with water, unlike dry risers which are empty pipes.

Wet risers also require less maintenance than dry risers, as they do not need to be charged with water by the fire brigade.

Additionally, wet risers are required in buildings over 50 meters tall due to the higher pumping pressure needed to charge the riser than what can be provided by fire service’s equipment.

Regular maintenance and inspections are important for wet risers to ensure normal operation and avoid unexpected malfunction in case of fire.