GB254772A - Improvements in or relating to apparatus for use in connection with the supply of feed water to steam boilers - Google Patents

Abstract

254,772. Myers, J. N. March 12, 1925. Fluid-actuated valves.-Feedwater is forced through a feed-heater into a gravity-feed apparatus in which the feeding pressure is maintained during charging, after which the pressure is so increased to boiler pressure as to allow the water to pass into the boiler without the increased pressure being transmitted to the feed heater. The apparatus consists of a cylinder A, Fig. 2, containing a steam tight piston B below which the feed is admitted through a pipe G and having pipes connected to its upper part for admitting and exhausting boiler steam through a pressure operated valve C. A spring loaded or like valve K in the steam exhaust pipe K<1> maintains a uniform back pressure in the cylinder while it is being supplied with fresh feed. A check valve prevents the boiler pressure from being transmitted to the feed heater and other auxiliaries. The sliding valve C, Figs. 4 and 6, is operated by boiler steam admitted to the top of a piston D' on the valve under the control of a pilot valve F operated by projections B<3> on a rod attached to the piston B. The projections engage in openings in a frame attached to the pilot valve and cause the valve to so slide backwards and forwards as to control ports allowing boiler steam to pass through passages C'. C<8> to the back of the piston D<1> or to exhaust through the passage C<8> and a pipe E<7>. Ports C<4> in the lining of the valve C place a pipe A<7> opening into the top of the cylinder A in communication with the exhaust pipe K<1> in the upper position of the valve, and with the steam admission pipe I<1> in the lower position of the valve. The piston B, the valve C and the pilot valve are formed or provided with rustless steel surfaces and work in rustless steel liners.