摘要 |
Apparatus and methods for operating a valve assembly for a dual chamber orifice fitting. The dual chamber orifice fitting comprises a body attached to a top. A passageway connects between the body and the top and allows an orifice plate carrier to move between the body and the top. A valve assembly selectably closes the passageway. Embodiments of the valve assembly comprise a seat, a plug, and a stem. The valve assembly has a closed position, wherein a curved outer surface of the plug sealingly engages a curved sealing surface of the seat and prohibits fluid communication through the passageway. The valve assembly has an open position, wherein a plug aperture is aligned with a seat aperture to allow the orifice plate carrier to move through the passageway.
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