GB1055902A - Improvements in or relating to steam traps - Google Patents

Abstract

1,055,902. Steam traps. SPIRAX-SARCO Ltd. Feb. 26, 1965 [March 17, 1964], No. 11304/64. Heading F4U. A steam trap of the kind described in Specification 755,178 has a temperature-controlled bleed valve 19 for allowing escape of fluid from the control chamber 9 when the temperature in the chamber is below a predetermined value. As the pressure rises in the steam plant condensate and air entering an inlet 2 passes up a bore 10, lifts a plate valve 16 and flows to the exhaust 3 portly by way of a groove 12 in the under-face of the valve 16 and passages 13, 15, and partly through the bleed valve 19 which is kept open by a bimetallic disc 26. As soon as steam arrives at the trap it flows into the chamber 9 and through the bleed valve 19 into the space 18, heating the bimetallic disc so that it becomes less dished and allows the steam pressure to close the valve 19. The rise in pressure in the chamber 9 causes the valve plate 16 to seat upon the groove 12 and escape of steam through the trap is prevented. When the pressure in the control chamber 9 drops the plate valve 16 is unseated and the hot condensate flows to the exhaust port 3. If, however, the drop in pressure in the chamber 9 is not sufficient to allow unseating of the plate valve 16 to discharge condensate, the fall in temperature causes the bimetallic disc 26 to become more dished and open the valve 19, whereupon the pressure in the chamber 9 is reduced and the plate valve 16 becomes unseated. Condensate is thus discharged; steam arrives in the chamber 9 and the bimetallic disc contracts allowing the steam pressure to close the valves 19 and 16. In a modification, the bleed valve closes the top of the valve orifice 23 and the bimetallic device is such that it expands with increasing temperature and maintains the valve 19 closed until the temperature in the chamber 9 drops.