Rotary drag valve
A valve assembly comprising a rotary closure element which defines an axis of rotation and is selectively movable between a fully open position and a fully closed position. Mounted to and movable with the rotary closure element is an impedance assembly. The impedance assembly defines an inflow end and an outflow end, and comprises a plurality of fluid passageways of varying noise attenuating capability which extend from the inflow end to the outflow end. Also partially defined by the impedance assembly is a flow opening which extends from the inflow end to the outflow end.
1. A valve assembly, comprising:
a rotary closure element defining an axis of rotation and selectively movable between a fully open position and a fully closed position;
upstream and downstream impedance assemblies mounted to and movable with the rotary closure element, the upstream and downstream impedance assemblies each defining an inflow end and an outflow end, and comprising:
a plurality of fluid passageways of varying noise attenuating capability extending from the inflow end to the outflow end, at least some of the fluid passageways being tortuous and defining a series of turns which extend at generally right angles relative to each other;
the upstream and downstream impedance assemblies and the closure element collectively defining a flow opening which extends from the inflow end of the upstream impedance assembly to the outflow end of the downstream impedance assembly.
2. The valve assembly of claim 1 wherein:
the upstream impedance assembly is configured and oriented relative to the closure element such that the fluid passageways thereof are each upstream of the axis of rotation when the closure element is in the fully open position; and
the downstream impedance assembly is configured and oriented relative to the closure element such that the fluid passageways thereof are each downstream of the axis of rotation when the closure element is in the fully open position.
3. The valve assembly of claim 1 wherein:
the upstream impedance assembly is configured and oriented relative to the closure element such that certain ones of the fluid passageways thereof include portions which are downstream of the axis of rotation when the closure element is in the fully open position; and
the downstream impedance assembly is configured and oriented relative to the closure element such that certain ones of the fluid passageways thereof include portions which are upstream of the axis of rotation when the closure element is in the fully open position.
4. The valve assembly of claim 1 wherein the fluid passageways of the upstream and downstream impedance assemblies define the same number of turns.
5. The valve assembly of claim 1 wherein:
the outflow end of the upstream impedance assembly has a beveled configuration; and
the inflow end of the downstream impedance assembly has a beveled configuration.
6. The valve assembly of claim 1 further comprising at least two reinforcement bolts which are each secured to the rotary closure element and advanced through respective ones of the upstream and downstream impedance assemblies.
7. A valve assembly, comprising:
a rotary closure element defining an axis of rotation and selectively movable between a fully open position and a fully closed position;
upstream and downstream impedance assemblies mounted to and movable with the rotary closure element, the upstream and downstream impedance assemblies each defining an inflow end and an outflow end, and comprising:
a plurality of noise attenuating fluid passageways extending from the inflow end to the outflow end, at least some of the fluid passageways being tortuous and defining a series of turns which extend at generally right angles relative to each other;
the upstream and downstream impedance assemblies and the closure element collectively defining a flow opening which extends from the inflow end of the upstream impedance assembly to the outflow end of the downstream impedance assembly.
8. The valve assembly of claim 7 wherein:
the upstream impedance assembly is configured and oriented relative to the closure element such that the fluid passageways thereof are each upstream of the axis of rotation when the closure element is in the fully open position; and
the downstream impedance assembly is configured and oriented relative to the closure element such that the fluid passageways thereof are each downstream of the axis of rotation when the closure element is in the fully open position.
9. The valve assembly of claim 7 wherein:
the upstream impedance assembly is configured and oriented relative to the closure element such that certain ones of the fluid passageways thereof include portions which are downstream of the axis of rotation when the closure element is in the fully open position; and
the downstream impedance assembly is configured and oriented relative to the closure element such that certain ones of the fluid passageways thereof include portions which are upstream of the axis of rotation when the closure element is in the fully open position.
10. The valve assembly of claim 7 wherein the fluid passageways of the upstream and downstream impedance assemblies define the same number of turns.
11. The valve assembly of claim 7 wherein:
the outflow end of the upstream impedance assembly has a beveled configuration; and
the inflow end of the downstream impedance assembly has a beveled configuration.
12. The valve assembly of claim 7 further comprising at least two reinforcement bolts which are each secured to the rotary closure element and advanced through respective ones of the upstream and downstream impedance assemblies.