GB668925A - Venturi valve - Google Patents

Abstract

668,925. Valve accessories; Venturis. ROCKWELL MANUFACTURING CO. Jan. 16, 1950 [Jan. 18, 1949], No. 1031/50. Classes 69 (i) and 135. A Venturi valve for use in large pipes to create a pressure difference which bears a definite ratio to the rate of flow, comprises a body 10, Figs. 1, 2, having a convergent passage 22 changing from circular crosssection at its inlet end to rectangular at its outlet end, a rectangular divergent passage 28, and a transverse tapered bore 12 between the passages for a rotary plug cock 14 having a rectangular hole 16 therethrough corresponding in shape and size to the inner ends of the passages. Adjacent the body 10 and on its downstream side is secured a conduit 48 having a tapered pressure recovery tube 30 changing from rectangular cross-section at its small end to circular at its large end. The tube 30 has holes 46 along its length to equalise the pressure on the opposite sides of the tube to enable it to be made of relatively thin material. In a modification, a passage 64, Fig. 9,. in the valve body connects the valve outlet with the space 62 between the conduit 48 and the tube 30, and in the case where the fluid is steam condensate collecting in this space is ejected through the passage 64 and carried along with the fluid stream. Spacing blocks 60 secured to the tube 30 provide passages between the space 62 and the tube and may, if desired, replace the holes 46. If desired the passage 64 may be replaced by short tubes secured to and passing through the wall of the tube 30 at its smaller end- Instead of being secured to the valve body 10, the tube 30 may be supported at its inner end on radial arms spaced around the tube between it and the conduit 48. Specification 601,158 is referred to.