Abstract: A valve suitable for use in equalizing the pressure in chambers of a blast furnace charging installation includes a seat member which may be removed for servicing through translatory movement perpendicular to the valve flow axis. The valve is also characterized by a valve member mounted on a pivotal arm in such a manner that articulation of the valve member with respect to the end of the pivot arm is permitted.

Abstract: A valve actuator, for example a mechanism for imparting motion to a blast furnace evacuation valve, includes a force generator which is coupled to the valve member by a displacement mechanism including a pivotal lever and a pivot arm. The pivotal lever has a pair of angularly related arms with the free end of one arm being coupled to the force generator and the free end of the second arm being coupled to a point on the pivot arm intermediate the ends thereof by a connecting rod or rods. The pivot arm is connected to the valve member and the connecting rod or rods are articulated to both the pivot arm and to the second lever arm which may be telescoping.

Abstract: A gas generator, for example a blast furnace, is isolated from an exhaust gas treatment system by means of an isolation valve characterized by a valve housing which may be permanently installed in the gas delivery conduit. The housing has a laterally offset recess which receives the valve member when in the open position and the valve member may define a liquid receiving vessel in the interest of establishing a liquid barrier between the interior of the conduit and the valve seat when the valve is closed. The valve is preferably hydraulically operated and the actuator is mounted so as to minimize loading on the control shaft bearings.

Abstract: The servicing of clay guns used in plugging the pouring holes of blast furnaces is facilitated by providing for the access to the sealant receiving cylinders of such clay guns through the front end thereof and without disassembling the clay gun from their actuators. Ease of access results from providing a cylinder front end extension which may easily be removed from axial alignment with the cylinder and which receives and accommodates at least that portion of the clay gun ejector piston which bears sealing rings when the piston has been extended to its limit of travel.

Abstract: Leakage of viscous material past an ejector piston, for example the piston of a clay gun employed in plugging blast furnace tapholes, is eliminated by a piston and ring design which exposes in excess of 50% of the leading and inner diameter surfaces of an expandable ring directly to the viscous material. Also, the leading face of the piston ring is outwardly inclined in the direction of piston travel and a complementary surface to this inclined face is provided on the piston. Expansion of the ring results from the reaction on the inclined face and inner diameter of the pressurized viscous material.

Abstract: The efficiency of operation of a taphole plugging clay gun for a blast furnace is enhanced by facilitating the cleaning of the sealant receiving chamber thereof behind the ejector piston which moves therein. Cleaning is facilitated by providing a protective casing which defines an annular chamber into which sealant leaking past or falling behind the ejector piston is forced; the annular chamber being provided with cleaning ports in the side wall.