Patent ID: 8490652

Claim:
A valve having a fluid flow path extending therethrough which is to be restricted or closed, comprising: a hollow valve body assembly having an inlet bore and an outlet bore substantially at right angles and a main bore which is an extension of the outlet bore and which communicates with the inlet bore; a flow trim positioned in the main bore, the flow trim comprising a stationary tubular cage having a side wall, and an external cylindrical flow collar adapted for sliding movement along the side wall of the cage, the side wall of the cage forming an internal bore aligned with the outlet bore and having a ported portion between its ends formed with one or more flow ports, the external flow collar being adapted for movement between a closed position, wherein the one or more flow ports are fully covered by the external flow collar, and an open position, wherein each of the flow ports is fully or partially uncovered by the external flow collar, whereby fluid may enter the valve through the inlet bore, pass through the one or more flow ports at reduced pressure and continue through the outlet bore; a bonnet disengagably connected with, and closing, an upper end of the valve body; a stem for biasing the external flow collar over the one or more flow ports; and the tubular cage being formed such that at least the ported portion includes a tubular outer cage member and a tubular inner cage member, the inner cage member and the outer cage member being formed from a tungsten carbide material, being concentrically aligned, having a length to span at least the ported portion, and being joined together by bonding at an interface formed between the inner cage member and the outer cage member.