US Patent 9217515 Reduced noise valve mechanism

A valve assembly is provided to control the flow of a fluid therethrough. The valve assembly includes a valve body and a pressure-regulating assembly. The valve body defines an inlet, an outlet, and a flow path extending therebetween. The pressure-regulating assembly includes a longitudinally extending piston tube, a venturi element, and a vent. The piston tube is shiftably mounted in the valve body and at least in part defines an outer chamber. The flow path extends through the piston tube. The venturi element is disposed in the flow path. The vent fluidly interconnects the flow path and the outer chamber such that a pressure drop associated with fluid flow through the venturi element draws fluid from the outer chamber through the vent and into the flow path.