A venturi valve is a reduced-bore valve having a bore smaller in diameter than the inlet or outlet. For example, an 8-in. x 6-in. x 8-in. ball valve has 8-in. inlet and outlet connections, while the ball and seats are 6 in. The flow through a venturi valve will be reduced because of the smaller port. Venturi valves can often be economically substituted for plug valves.