GB801317A - Improvements in or relating to turbine control valves - Google Patents

Abstract

801,317. Turbines. VICKERS - ARMSTRONGS (ENGINEERS), Ltd. May 16, 1956 [June 8, 1955], No. 16491/55. Class 110 (3). [Also in Group XXIX] A turbine having nozzles arranged in a plurality of groups each of which is supplied by a separate channel is controlled by a valve comprising a valve body with an inlet and outlets one for each channel and a valve member arranged between the inlet and outlets which is capable of assuming a number of different working positions and has a series of ports for co-operating with each outlet, the working position of the valve member determining which particular port, if any, in each series co-operates with its associated outlet, the arrangement being such that the different working positions connect different combinations of channels with the valve inlet. The steam inlet 22 to the turbine 21 is divided into three channels 23, 24, 25. The channel 23 leads to a group of two nozzles, the channel 24 to four nozzles and the channel 25 to eight nozzles. A valve body 27 bolted to the inlet flange 26 has an inlet 28 and outlets 31, 32, 33 leading to the channels 23, 24, 25. A hollow slightly tapered valve member 37 has four apertures 38 through which steam flows from the inlet 28 to the inside of the valve member, a first series of ports 40, 41, 42, 43 leading to the passage 31, a second series of ports 44, 45, 46, 47 leading to the passage 32 and a third series of ports 48, 49, 50, 51 leading to the passage 33. The valve member 37 has a spindle 52 supported in a bearing 55. A bush 58, in screwthreaded engagement with the spindle 52, is mounted in a conical housing 56 by bearings 61, 62. The bearings 61, 62 engage a collar 59 to prevent endwise movement of the bush 58 which is rotatable by a hand wheel 65. An extension 52A of the spindle carries a hand wheel 66 with recesses 72 which co-operate with a spring-loaded plunger 71 to locate the hand wheel in each of seven positions. In each of these positions a different number of nozzles are connected to the steam inlet. To operate the valve, the hand wheel 65 is rotated which causes the valve member 37 to move away from the boss 76 and metal-to-metal contact between the valve member and valve body ceases. The hand wheel 66 is then rotated to the desired position and the hand wheel 65 is then turned to move the valve member 37 toward the boss 76 until metal-to-metal contact reoccurs.