Abstract: A liquid level controller system and process wherein the liquid level controller is attached to a separator vessel so as to monitor fluid level within the separator vessel. The liquid level controller is configured such that hydrocarbon deposits, which hydrocarbon deposits build up in the d displacer arm chamber of the level controller, and be cleaned out without disconnecting the liquid level controller from the separator vessel and without disconnecting the displacer arm assembly from the pilot assembly.

Abstract: A pilot valve is switchable between snap and throttle modes. The pilot valve supplies output gas to a process control valve and has an adjustable biasing member for applying an adjustable force to a pilot plug in a pilot body interior. An opposed force is applied to the pilot plug to overcome the adjustable force and the output gas.

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.