Liquid level controller and pilot switch
AssigneeKimray, Inc.
InventorGarman Oscar Kimmell
Life of this patent
Estimating the term…
Abstract
A liquid level controller including a pilot valve switchable between snap and throttle modes. A displacer translates changing liquid level in a tank into movement that is transferred to the pilot valve which will provide output gas to a control valve to allow or to prevent the discharge of fluid from the tank. The pilot valve has a throttle supply inlet and a snap supply inlet and a single output passage. When the pilot valve is in the throttle mode, the snap supply inlet is a vent passage and when the pilot valve is in the snap mode, the throttle supply gas inlet is a vent passage.
Claims22
A pilot assembly switchable between a throttle mode and a snap mode comprising:
- a pilot body having a throttle supply gas inlet, a snap supply gas inlet and a single output gas outlet for providing output gas to a process control component;
- a pilot plug in a pilot body interior, the pilot plug having a first sealing element engageable with a first seat, and a second sealing element engageable with a second seat;
- a variable force biasing means for applying a force to the pilot plug to urge the first sealing element in a direction toward the first seat;
- and
- a switch movable between first and second positions for selectively directing supply gas to throttle supply gas inlet in throttle mode and the snap supply gas inlet in snap mode, respectively, wherein supply gas passing through the selected of the throttle and snap supply gas inlets is communicated through the single output gas outlet to the process control component.
A pilot switch comprising:
- a pilot body with first and second supply gas inlets and a single output gas outlet;
- a switch for selectively directing supply gas to a selected one of the first and second supply gas inlets, wherein the pilot operates in throttle mode when supply gas is directed to the first gas inlet and in snap mode when supply gas is directed to the second supply gas inlet;
- a pilot plug having first and second sealing elements disposed in the pilot body, the first sealing element being engageable with a first seat, the second sealing element being engageable with a second seat, the first seat being positioned between the first supply gas inlet and the output gas outlet, the second seat being positioned between the second output gas inlet and the supply gas outlet;
- and
- a loading mechanism for applying a force to the pilot plug to urge the first sealing element in a direction toward the first seat, the loading mechanism being variable to apply a first force in throttle mode and a second, increased force in snap mode.
A pilot assembly comprising:
- a pilot body defining a pilot body interior, the pilot body interior comprising a throttle chamber and a snap chamber;
- a pilot plug disposed in the pilot body interior, the pilot plug comprising an upper and a lower sealing ball connected by a pilot plug stem;
- an actuator movable in the pilot body interior, the actuator defining a lower seat engageable with the lower sealing ball;
- a seat body affixed in the pilot body interior defining an upper seat engageable with the upper sealing ball;
- a biasing means for applying a force in a direction to urge the upper sealing ball toward the upper seat;
- a throttle supply gas inlet communicated with the throttle chamber;
- a snap supply gas inlet communicated with the snap chamber;
- and
- an outlet for communicating the supply gas from a selected one of the throttle supply gas inlet and the snap supply gas inlet to a process control unit, the pilot being switchable between a snap mode and a throttle mode to operate the process control unit wherein in throttle mode the supply gas operates to counteract a portion of the force applied by the biasing means.
Dependencies are inferred from the claim text.