GB580259A - Cut-off or control valve for steam or gas turbines with high working temperatures - Google Patents

Abstract

580,259. Valves. ESCHER WYSS MASCHINENFABRIKEN AKT.-GES. March 23, 1944, No. 5423. Convention date, March 26, 1943. [Class 135] In a cut-off or control valve for steam or gas turbines with high working temperatures, working medium at a lower temperature than that which comes into contact with the valve closure member and its spindle is introduced into the gap between the valve spindle and at least one of the valve spindle guides to cool the valve spindle and so prevent its distortion at very high temperatures. The working medium so introduced is at a higher pressure than that on the inlet side of the valve. As shown, working medium is introduced by a pipe 5 to the guide sleeve 4. This supply may be taken from the inlet side of a superheater or from an intermediate point of the latter. The valve casing 1 is furnished with liners 6, 7, 8, 9 forming cooling spaces 6<1>, 7<1>, 8<1>, 9<1> and working medium which passes down the spindle 3 passes through a port 11 into the space 6<1> and thence via a pipe 12 into the space 9<1>. Working medium also passes through a pipe 13 into the spaces 7<1>, 8<1>. Openings 18, 19 connect the spaces 8<1>, 9<1> with the outlet and inlet sides of the valve respectively. The pipe 13 is connected to the outlet chamber 15 by a byepass pipe 14 containing a valve 16 opened automatically when the pressure difference between the spaces 7<1> and 15 becomes too great. Any working medium which passes up the valve spindle is led off by a pipe 21 to a point where it can be used as, for example, to a lower pressure stage of a steam turbine. A modification is described in which the cooling medium is also introduced into the valve member 2 and into a lower spindle guide by means of passages in the valve member and its spindle. The passages may, however, be arranged to pass straight through the spindle to the lower spindle guide.