Compressor type vessels are conventional gas/liquid interface vessels and have a control system that ensures the gas/liquid volumes are as per design conditions.
Such vessels are supplied with compressors and solenoids to ensure accurate control of gas volume. The change in liquid level is detected by a level instrument, which may be a simple bypass level gauge containing a magnetic float that rises and falls with the liquid level activating magnetically sensitive switches attached to the level gauge or a more advanced level instrument, such as a radar or ultrasonic level detection instrument.