Self-pressure single-seat regulating valve does not require any external energy, for the valve can transfer the medium energy to realize auto regulate. It has two form sealing type:soft and hard seal. The series products have characteristics of sensitive movement, high performance of sealing, stable medium pressure, high precision regulating, energy-saving and so on. The valve pressure settings can be freely adjusted in the running period, and applicable for a variety of medium automatic adjustment , decompression, steady pressure (valve downstream), or pressure relief, steady pressure (for valve upstream).