GB568811A - Improvements relating to apparatus for producing foam for fire extinguishing purposes - Google Patents

Abstract

568,811. Valves. PYRENE CO., Ltd., and HUNTER, J. N. Aug. 23, 1943, No. 13752. [Class 135] [Also in Group XXI] Backward flow of oil from an oil storage tank 1, Fig. 1, through the air inlet 17 of a branch pipe 9 for producing air foam for fireextinguishing connected thereto, is prevented by an automatic non-return valve incorporated in the branch pipe. Fire risk is thus reduced in the event of a failure or reduction in pressure of the foam supply to the tank through the coupling 7 and pipe 2 by which the oil is fed to and withdrawn from the tank. A non- return valve, comprising a ball 18, Fig. 3, mounted in a cage 19, is mounted in a throat 14 in the branch pipe 9 and is moved, if it sticks, by a handle 27, which rocks a rod 21 journalled in openings in the wall of the flaring port 15. A rod 20 projects into the cage and depends from the rod 21 to move the ball 18 when the handle is operated. In another arrangement, Fig. 5, the valve is in the form of a clack valve 28 pivotally mounted at 29 in an offset part 36 of the wall of the branch pipe, and preferably at the end of the flaring port 15. In a further form, Fig. 6, a clack valve 28 has a rod 33 pivoted in bearing and to which is keyed a cranked lever 32 by operating which, by rod 35 having a lost motion connection therewith, the clack valve may be moved. Specifications 403,291 and 568,658, [both in Group XXI], are referred to in the Provisional Specification.