i work in fire safety and i would have to be honest i wouldn't know if a valve had to be fitted, although i will watch out for it in the future. i would suggest contacting the company that carried out the installation as they should be the experts and more likely to know the answer. i would have thought once the fire service connect on to the raising main the air would be naturally vented when the valve is opened at what ever floor and the fire fighter would have procedure to ensure they have water at the hose before entering any fire. Of course I'm just guessing but i would contact the installer first. maybe number of outlets or total height of dry riser might have some affect as to if one is required or not. Without checking but i believe they need servicing/inspection every 6 months Phil

in such systems there should not be a situation where an air block or similar e.g. dog leg could occure which would restrict and/or stop the flow of water/fire fighting substances - ask your pipework designer

Hi As Chris states – it is very unlikely that an air release valve has not been fitted. The installation company ought to provide you with the design features and specification. The new document, 'BS 9990'/2006, brings up to date the guidance on dry and wet fire mains, or risers, which was previously covered by BS 5306 Part 1. The principal changes from BS 5306 are that the new standard no longer gives guidance on when and where such systems are needed, as this is now given in guidance supporting the building regulations. The new Code deals solely with design, provision, siting, installation and maintenance. (Guidance on hose reels and foam inlets remains in the revised BS 5306 pt 1.) The annual testing and maintenance of both Dry and Wet Risers is the responsibility of the property owners or managing agents, carried out by competent person.

Thanks all you guys for your responses. As Chris points out i presumed that a air valve should be fitted, but as there was not one readily noticeable it cast doubt in my mind. Meeting with the company that fitted the riser later this week so i should have a definate answer.