Full-bore flow valves that provide on/off control with minimal pressure drop. The valve opening has a constant pipeline diameter which enables fluids to flow freely through the valves when open. Flow restriction is comparable to that of a straight tube. Suitable for handling fluids that are viscous or contain solid, semi-solid or abrasive particles in the food, beverage, chemical and pharmaceutical industries. For use wherever there is pigging of process lines, applications that require gentle product treatment, and CIP applications. Can be supplied with either automated or manual control.