| 摘要 |
<p>A rotary noise attenuating valve is provided which utilizes noise attenuation technology previously utilized with linear valves. The arrangement includes an impedance assembly in which the area with the impedance assembly which is accessed by the flow downstream of a rotary closure element flow is varied upon opening of the rotary closure element, with an interface assembly disposed between the rotary closure element and the impedance assembly. As a result, benefits previously realized only in linear valves are attainable utilizing a rotary valve, while the benefits attendant to rotary valves (such as greater capacity, variable DELTA p and/or minimum DELTA p under max flow) are also attainable. Attenuator assemblies are also provided in which the attenuator or impedance structure is mounted within the valve, either downstream of the closure member, or mounted to the closure member. In a preferred form, in the more fully open positions of the valve, at least some of the flow is allowed to pass without passing through the impedance assembly.</p> |
