Air separation equipment​ is a device that uses air as raw material, converts the air into liquid state by means of compression cycle deep freezing, and then gradually separates it from liquid air to produce inert gases such as oxygen, nitrogen and argon through rectification.

The horizontal pump is horizontally arranged (the liquid inlet pipe is lower than the liquid discharge pipe), and heating gas (set behind the pump or in front of the filter in front of the pump to prevent impurities from entering), seal gas, liquid discharge exhaust valve (discharge at low place and exhaust at high place) and return pipeline (return liquid inlet phase) are required.

In the process of full low pressure switching air separation unit​, a bypass valve is usually installed on the pipeline from the air to the switching heat exchanger and from the waste nitrogen to the switching heat exchanger, which plays a very important role in the start-up stage: part of the cooled air can return to the switching heat exchanger through the bypass valve to release the cooling capacity.