Improvements in or relating to rotary fluid control valves

785,149. Valves. ROBERTSHAW-FULTON CONTROLS CO. Sept. 20, 1955 [Feb. 16, 1955], No. 26895/55. Class 135. A header 16, Fig. 1, fixed in the lower part of the valve casing 10 is provided with a number, four as shown, parallel through conduits 26, 28, 30 and 32, Fig. 3, each opening into a copper tube 36, Fig. 1, and four normal flow conduits 26, 30 and 28, 32 which are interconnected by a closure member 38, with a lapped surface 39, that is rotatable on the lapped surface of the header in a fluid-tight manner. A dividing wall 40 divides the member 38 into low and high-pressure chambers 42, 44 the former chamber enveloping the tops of conduits 28, 32 and the latter enclosing the tops of conduits 26, 30; if the member 38 is rotated through 180 degrees the chambers 42 and 44 interconnect conduits 28, 30 and 26, 32 and provide for reverse flow through the associated refrigerating or other apparatus. A port 52 in the member 38 opens the interior of the casing 10 to the chamber 44 so that the fluid therein, acting on a larger area of the member 38 than does the fluid in the chamber 44, forces the member 38 on to the header 16, and to reduce this force during rotation of the member 38 there is provided a selector 54 pivoted on a pin 58 and free to rotate between two stops 60, 62, Fig. 2; the selector 54 is biased to the stop 62 by a spring 64. A port 68, Fig. 1, larger than the port 52, extends through the wall of the member 38 to place the interior of the casing 10 into communication with the chamber 42 during valve operation; the selector 54 normally covers the port 68 but when the port is open it enables the fluid in the casing 10 to flow into the chamber 42, thus reducing the force urging the member 38 on to the header 16. The selector 54 receives one end 74 of a flexible bellows 76 the other end of which is attached to a flange 18 on the casing 10, the bellows hermetically sealing the interior of the latter; a curved shaft 78 joins an operating handle 80 to the end 74 of the bellows. Rotation of the handle 80 first moves the selector 54 alone until the stop 60 is encountered whereupon continued movement of the handle causes the member 38 to rotate relatively to the header 16; upon releasing the handle 80 the spring 64 brings the selector 54 back against the stop 62 and covers port 68.