Assembly of orifice chambers progressively reducing operating pressure for large gas flows

An improved assembly of orifice chambers for the progressive reduction of operating pressures of gas flow effective to reduce noise of the gas flow and wear on the orifice chambers comprising,

• a body having a flowway, an inlet and an outlet for the gas flow therethrough,
• an annular internal shell secured in the flowway to the body by a centering ring adjacent the inlet and a brace adjacent the outlet, spacing the internal shell from and providing an annular space with the body effective to permit thermal expansion and contraction of the internal shell caused by the gas flow in the flowway,
• a plurality of orifice plate supports secured to the annular internal shell and extending partially into the flowway spaced from one another in the direction of the gas flow,
• one or more orifice plates releasably secured and supported by the orifice support plates thereby forming the orifice chambers, removal of one or more of the orifice plates providing an access manway to the next succeeding orifice chamber in the direction of the gas flow,
• the one or more orifice plates provided with one or more orifices effective to provide a gradual progressive pressure drop in the gas flow as it flows successively through the orifices in the orifice plates, and
• a manway having a releasable closure in the body upstream from a first of the orifice chambers and the annular internal shell thereby providing access to the first of the orifice chambers and removal of the one or more orifice plates of the first and successive orifice chambers in the direction of the gas flow and provides the access manways to the next and the successive orifice chambers and their orifice plates.