The 97/98-21000W series single seat bellows sealing valve is a new generation of bellows sealing regulating valve product developed based on the 21000 series single seat valve and absorbing advanced technology of bellows sealing valves at home and abroad. It not only maintains the characteristics of good stability, low leakage, and wide range of use of the 21000 series single seat valve, but also effectively prevents the process medium from leaking out of the valve packing box due to the use of a corrugated pipe sealing structure combined with the packing seal to form a double seal. This series of products is particularly suitable for controlling highly toxic, valuable, volatile, and radioactive media, as well as for vacuum applications.