Abstract: A flow setting assembly is provided to permit field adjustment of an electronically actuated flow control valve, particularly a pressure independent characterized control valve (PICCV). In a preferred form, flow can be field adjusted by using a hex tool. Therefore, the maximum flow can be increased or decreased within the valve's adjustable flow range. As with all high close-off valves that employ a ball in their design, the ball passes well into the seat when rotated to the actuator's zero-degree position. Therefore, there is an amount of travel within the first degrees of ball rotation that passes back over this seat. The flow setting assembly eliminates this excess rotation (12°) resulting in a closed position that is offset to improve control resolution and system accuracy. This offset continues to allow the high close-off rating of 200 PSI. MFT actuators electronically adjust to and maintain the 2-10 Volt control signal at the reduced angle, as well as the 100 second running time and feedback signal.

Abstract: An electric-arc discharge device includes an annular gas-flow nozzle surrounding the discharge electrode, the nozzle being configured for discharging gas flows at trans-sonic to supersonic velocity, with circumferential uniformity of the gas flow around the axis of the electrode, and directed downstream to surround and radially inwardly confine and shape the arc. The trans-sonic speeds of gas discharge are the result of special annular gas-nozzle design and suitable pressure of gas supply thereto, whereby a region of criticality characterizes gas flow within the nozzle, i.e., prior to discharge at trans-sonic speeds, the discharge being around the electrode and with such thrusting momentum as to establish shaping confinement and directional stability of the region of electric-arc development.