Dry riser gate valves act as outlets from the riser main.These valves are situated on each floor of the high rise building and are normally housed in outlet cabinets which are manufactured to BS5041 part 4. Dry riser gate valves come complete with inlets flanged 65mm BS4504 PN16, 2.5”BS10 table D and screwed 2.5” BSPT, outlets to BS336, complete with blank cap and chain, strap and padlock, complying to BS5041 part 2. To the top of riser should be fitted with an air release valve which releases all air from the riser, as water is pumped in, but closes automatically under pressure of water. A 1” drain valve can be used at the bottom of the riser if the pipe work goes below the inlet breeching valve, so the system can be completely drained.