ZMA/BP (N) -10~40W pneumatic thin film bellows sealing regulating valve, including two types of pneumatic thin film straight through single seat bellows sealing regulating valve and pneumatic thin film straight through double seat bellows sealing regulating valve, is a modified product of pneumatic thin film straight through single and double seat regulating valve, with the advantages of simple structure and reliable operation. The upper valve cover adopts a corrugated sealing structure and is combined with the packing seal to form a double sealing form, which can safely and reliably prevent the process medium from leaking out from the valve stem gap. Therefore, it is particularly suitable for regulating highly toxic, valuable, volatile and radioactive media, and is also suitable for pipeline vacuum situations.

Structural characteristics:
1. Pneumatic diaphragm straight through single seat bellows regulating valve: There is only one valve seat inside the valve, which has the advantage of small leakage, but the unbalanced force is large. Due to the limitation of the output force of the pneumatic diaphragm actuator, the working pressure difference should not be too high.
2. Pneumatic thin film straight through double seat corrugated tube regulating valve: There are two valve seats inside the valve, which have the advantages of high flow capacity and low unbalanced force.
3. The bellows assembly with anti rotation structure is connected with the valve core, which can prevent the bellows element from being damaged due to the torsion caused by adjusting the stroke during assembly.
4. It has a dual sealing structure: a PTFE V-shaped packing sealing area is provided at the upper end of the upper valve cover. Once the bellows component fails, it can be used as a second seal, increasing the sealing safety of the pneumatic bellows regulating valve.
5. The upper end of the valve stem has a left-hand thread, so that the stroke can be adjusted by connecting the nut when the valve stem cannot rotate.