Pressure equalization valve and technique for shaft furnace

A pressure equalization valve comprising:

• valve body means, said body means being adapted for connection between a pair of spacially displaced conduits, said body means defining a fluid flow path having an axis, said valve body means having end portions circumscribing said flow path, said body means being provided with a lateral opening at one side thereof;
• removable cover means for said body means lateral opening;
• a conduit section, said conduit section having an axis aligned with the fluid flow path axis of said valve body means, said conduit section having end portions circumscribing said flow path, said conduit section being displaced from said body means along said aligned axes;
• valve seat means, said valve seat means being transversely movable with respect to said aligned axes and having a generally annular shape, said valve seat means being positioned between said body means and said conduit section and in contact with facing end portions thereof when in the installed state, said seat means defining a valve seat having an aperture axially aligned with said fluid flow path;
• means for clamping said seat means between said body means and said conduit section facing end portions, said clamping means interconnecting said valve body means and said conduit section, said seat means being removable from said valve in a direction transverse to said fluid flow path axis upon loosening of said clamp means without interruption of the connection between and the axial alignment of said body means and said conduit section, said clamp means when in the tightened condition causing establishment of a hermetic seal between each of said body means and said conduit section and said seat means, said clamp means further including means for urging said body means and conduit section apart in the axial direction upon the loosening of said clamp means;
• a rotatable control shaft, said control shaft passing through said body means;
• means for imparting rotary motion to said control shaft;
• a valve member disposed within said body means, said valve member having a sealing surface which cooperates with the seat defined by said seat means to perform a valving function;
• pivot arm means, said pivot arm means being connected adjacent a first end thereof to said rotatable control shaft;
• and
• means coupling said valve member to said pivot arm means adjacent the second end thereof whereby rotation of the control shaft will result in said valve member moving between a closed position wherein said sealing surface is in contact with said valve seat and an open position wherein said valve member is disposed adjacent to said body means lateral opening, said coupling means permitting articulation of said valve member with respect to the second end of said pivot arm means.