(under subclass 12) Subject matter in which the valve has the opening or closing forces acting thereon augmented or altered by a force resulting from a fluid pressure derived from the velocity flow of fluid in the line acting on a reactor surface other than the valve head or closure element.
SEE OR SEARCH THIS CLASS, SUBCLASS:
37, for choked fluid pressure type servo-motors having a choke or restriction in the main line.
123+, for valves located at a point of restriction in a line.
SEE OR SEARCH CLASS
137, Fluid Handling, 219+, for Larner-Johnson valves, in which the needle seats on a restricted portion of the flow line and subclasses 497+ for valves having a separate connected fluid reactor surface and adjusted entirely by variations in fluid flow in the line, especially subclass 502 for expansible chamber reactors subject to differential pressures, one pressure being that at the throat of a Venturi tube.
