GB327436A - Improvements relating to dry-pipe fire-extinguishing sprinkler systems - Google Patents

Abstract

327,436. Woosnam, A., (Automatic Sprinkler Co. of America). Dec. 3, 1928. Sprinklers, automatic.-A dry pipe sprinkler system in which the main valve opens as usual in case of a fall of pressure in the distributing pipes consequent upon the opening of a sprinkler head, is provided with means whereby a rise of pressure in the air pipes, or in a supplemental piping in the fire zone, due to heating thereof. will also cause the main valve to open in advance of the opening permitted by the fusion of a sprinkler head. As shown, the casing 3 for the dry-pipe differential valve 4, 5 has a neutral chamber 3<1>, and the air pipe 7 is connected by a pipe 9 to a casing. This consists of two chambers 10, 11 separated by a diaphragm 13 and normally maintained at the same pressure by a " bleeder " device 12. The chamber 3<1> is connected to the chamber 10 by a pipe 20 closed by a valve 19. If the air pipes, such as 7, are heated by a fire before the fusible heads 8 open, the pressure in chamber 10 rises and the diaphragm. is lifted. This opens the valve 19 through a rocker arm 16 and weighted lever 17, allowing air under pressure to pass to the chamber 3<1>, causing the main valve 4, 5 to open. If a head 8 opens first, the pressure in chamber 10 falls and the diaphragm 13 moves down, again opening the valve 19. The air entering chamber 3<1> will now accelerate the normal opening of the main valve. An air pump 22 used for replenishing the pressure in the air pipe system is connected by a pipe 25 to a chamber 26 separated from the chamber 10 by a diaphragm 27 and a valve 31. When the diaphragm 27 is distended by pressure in the chamber 26, it carries forward a rod 28 which opens' the valve 31 by means of a bellcrank 30. The rod 28 also serves to lock the rocker 16 against movement, so that increased pressure at this time in the chamber 10 cannot cause the diaphragm 13 to open the valve 19. An extension 34 carried by the diaphragm 13 serves to prevent the retreat of the rod 28 until the diaphragm is in its normal, central, position. Specifications 326,141, 326,142, and 330,254 are referred to.