The super-large air separation plant is composed of an air compression system, a large-scale air pre-cooling system, an extra-large molecular sieve purification system, an air booster system, a booster turboexpander system, an extra-large rectification system and a heat exchange system. Due to the large size of the supporting unit equipment and the high requirements of the manufacturing process, the selection of the supporting valve is particularly important, which is directly related to production safety, system adjustment performance, output quality and investment costs.