DISCRETE-CONTROLLED VALVE UNIT Russian patent published in 1996 - IPC

FIELD: oil production. SUBSTANCE: discrete-controlled valve unit includes hollow case with upper and lower cylindrical passages. Separating member in the form of bellows or piston is installed in upper case part to from pressure-tight chamber together with case. The chamber is filled with gas under preset pressure. There is a stem lower end of which is rigidly related to valve slide. The stem comprises two telescopic parts interconnected through fixing unit with different space between the ends of those. Lengthwise through grooves are originated in hollow case above the valve slide. Space between lower (or upper) slide butt to lower (or upper) ends of lengthwise through grooves is determined on the base of equation of equilibrium of forces drawn for initial and work position of the unit. Movable seat with spring under may be positioned in the case under the slide. Throttle passage may be provided in the slide valve that is used as communication between cavities under and over the slide. Flutes (passages) or slots for fixing unit are provided along the length of upper (and) lower stem parts. Fixing unit may be made in the form of balls or keys installed in radial passages of upper and lower stem parts under movable sleeve. Springs placed under the fixing unit are used to stop it in initial position. The unit is made fast in this position by screws. A pin or screw installed in radial passages of upper and lower parts of the stem may be used as stopping unit. Thrust sleeve may be installed inside the stem between its two parts. Additional lengthwise flute (grooves) may be originated in the case. Though radial passages may be originated in the middle of the flutes. Balls are placed inside these passages. On one side the balls are interacted to bead (beads) of the stem. On another side they are interacted to elastic members made in the form of spring wire or plank. Elastic members are installed in lengthwise cylindrical passages or trapezoid slots originated in the form of "swallow tail" in case body. Cross section area of the slide is equal to or higher than bellows or piston area that is under action of gas pressure in pressure-tight chamber. EFFECT: high capacity.