简要描述：retz品牌 进口气动针型阀采用两截阀杆设计，上阀杆螺纹的润滑脂与系统介质隔离，旋转的下阀杆上下运动代替旋转升降，减低每个过程对填料的磨擦，减少阀座和阀头之间的咬合，阀门在全开位置具有背密封功能，确保工作状态下不会发生泄漏，在相应的温度下密封件不会发生密封不严 The imported pneumatic needle valve adopts the design of two valve stems. The lubricating grease on the upper valve stem thread is isolated from the system medium. The rotating lower valve stem moves up and down instead of rotating up and down, reducing the friction on the packing in each process, reducing the bite between the valve seat and the valve head. The valve has the back sealing function in the fully open position to ensure that there is no leakage under the working condition, and that the sealing element will not be loose at the corresponding temperature