GB179243A - Improvements in steam reducing valves - Google Patents

Abstract

179,243. Wingfield, B. R., and Steam Fittings Co., Ltd. Jan. 24, 1921. Valves controlled by pilot or relay valves. - A steam pressure - reducing valve is controlled by the temperature of the steam at reduced pressure by means of a thermo stat, operated by the expansion of a liquid, acting on the reducing - v a l v e through the medium of a pilot valve. The thermostat comprises a tube 1 filled with liquid and containing a spirally-corrugated metal tube G, the lower end of which is fixed to the base H, and the upper end to a cap K carrying a rod F terminating in a valve D. A similar corrugated tube N is arranged in the upper part of the tube 1, and its rod P carries a nut Z having a pin B<1> projecting into a slot B<2> in a fixed sleeve A. The nut Z is pressed downwards by a spring D" and is prevented from turning relatively to the sleeve A<1>. The latter may be rotated on slackening the nut C<1>, in order to adjust the tube N upwards or downwards to vary the initial setting of the valve D. Steam flowing through the inlet 10 passes through the valve D and pipe X to operate the piston C and thus lift the main valve B to allow the steam to pass to the outlet. The reduced steam passes through the conduit V to the casing R, so that if its pressure and consequently its temperature become too high, the thermostat is actuated and the valve D is partly closed, which results in a corresponding partial closure of the valve B. Any increase in temperature of the thermostat after the valve D is closed produces a further expansion of the liquid which is absorbed by the compression of the spring D<11>. Specifications 25086/13 and 4190/15 are referred to.