Pressure Swing Adsorption (PSA) plant ususes molecular sieves as adsorbent to separate O2 and N2 according to their different adsorption quantities. The purity of O2 can be 93% and N2 can be 99.5% to 99.99%. Moreover, the equipment is characterized by quick startup, high automation, compact structure, small occupation area, and more. Therefore, PSA plant is very applicable for those clients who do not require high production and purity.