A Typical Dry Riser
What Are Dry Risers?
Dry Riser systems comprise vertical mains normally fitted into staircase enclosures with outlet valves on each floor ready to deliver a supply of water to fire fighting hoses. An external inlet valve at ground level enables connection with a water supply, normally from a fire appliance (fire engine). Dry risers are normally installed in buildings which are more than 18m high, although if a building has more than 18 storeys then a wet riser (which is permanently charged with water) will be installed.
Do I Have A Dry Riser?
As mentioned above, buildings which are above 18m are likely to have a dry riser installed. They are very distinctive and often labelled so that fire crews can easily identify their location in the event of an emergency.
The are large vertical pipes usually black in colour and are approximately 25cm in diameter. They are unlikely to be visible as they are normally “boxed in”, but steel cabinets with closing doors will be visible at each floor level.
Do I Need to Maintain My Dry Riser?
BS9990:2006 recommends that a full visual check is made every six months with a full test at pressure every 12 months. In a fire situation, the riser will be pressurised to 10 bar immediately so it is crucial that all inlet and landing valves and associated washers are sound and the riser itself is clear of debris.
During the 12 month test, the Code recommends that initially the top valve of the system should be opened and the system flushed out to remove any debris (in public car parks the debris is often discarded syringes). The system should then be charged and held at its design operating pressure (normally 10 bar) for 15 minutes whilst the pressure and all valves are monitored. The Code also states that this maintenance procedure should only be carried out by a competent person – Hurst Solutions have team which carry out this specialist type of work and are equipped with fire appliances to enable them to carry it out effectively.
For more information or a quotation please do not hesitate to contact us.
