Abstract: An isolation valve purge system for an isolation valve, with internal components configured to isolate the flow of process fluid through the bottom slurry circuit line. In some embodiments the isolation valve is purged using a liquid purge medium created in the fractionation tower, such as a hydrocarbons, oils of different viscosity or a combination of hydrocarbons. A method for reducing cavitation in a pressurized line by using a hydrocarbon from the fractionation tower to purge an isolation valve process fluid flowing therethrough with a liquid purge medium.

Abstract: The sliding parts, the guides and interlocking portions of the interlocking guides and slides of a slide valve are all disposed away from a flow path through the valve. Additionally, the portions of the interlocking guide on the slide or disc of the valve that interlock with the guide on an orifice plate are connected to the slide or disc by welds instead of bolts, greatly increasing durability. As the slide or disc moves in and out to control the flow rate precisely, the guides of the slide or disc move with it. Because the sliding surfaces of the orifice plate and the slide or disc are outside of the flow path, they are consequently not subjected to erosion from the flow through the valve. Accordingly, all critical sliding surfaces are not exposed to the flow path and are greatly increased in durability.

Abstract: Actuators for fluid catalytic cracking unit slide valves and similar valves are disclosed. The actuator frame is assembled by bolting, allowing for standardized configurations that permit stocking of parts and avoids prior art problems of dealing with actuators designed for each individual project, allowing for rapid assembly of new actuators on demand that suit each project by varying the incorporated components, as well as permitting for more-rapid servicing when necessary. Additionally, the instrumentation for the actuator is contained within the actuator frame, better protecting the instrumentation from damage such as from being struck. The actuator includes a new manual engagement system, providing for better engagement of manual controls to actuate the actuator and the accompanying valve when necessary.