Morning gents,
After speaking with BASFA I do not feel as bad as even they were puzzled by the question!!!!!
However I have had a breakthrough this morning and found this information in the Fire Service manual for your interest-
According to the BS/LPC Rules a sprinkler installation should be based on one of the following main
types:
? Wet pipe system
? Dry pipe
? Alternate (wet and dry pipe)
? Life safety
? Pre-action
? Recycling
? Deluge
Systems based on the first two types above may also include extensions of an additional type as:
? Tail-end alternate
? Tail-end dry type
Tail-end systems (dry pipe or alternate)
These systems are essentially similar to those previously described, except that they are of comparatively small extent and form extensions to standard sprinkler installations. They are permitted:
(a) As extensions to a wet pipe system in comparatively small areas (I) where there is possible frost danger in an otherwise adequately heated building, and (II) in high temperature areas or stoves. The tail-end would he on the alternate wet and dry principle in the case of I) and on the dry pipe principle for (II).
(b) As extensions to an alternate wet and dry system in high temperature areas or stoves, when tail-end systems would be on the dry pipe principle.
Sprinklers in tail-end systems must be installed in the upright position above the lines of pipes, an exception being if approved dry pendant pattern sprinklers are installed.
The number of sprinklers in a group of tail-end systems controlled by one set of wet pipe system or alternate wet and dry pipe system valves, must not exceed 250 in total, with not more than 100 sprinklers on any one tail-end system. Each tail- end system must be provided with a 50mm drain valve and drainpipe.
A pressure gauge must be fitted at a point above the seating of the tail-end valve. A subsidiary stop valve may be fitted below the tail-end valve, providing it is of the interlocking key type and in a conspicuous position. When the valve is temporarily closed the key must be readily visible.