2. Modulating the air pressure within the annular space between the body and the sleeve can open, throttle or close the valve. 在阀体和套管的环形空间内施加气压,就能够实现开启、节流或关闭阀门的功能。
3. Introduce the massive concrete construction technique and experience in annular beam of Nantong gymnasium meeting and exhibiting center. 介绍了南通市体育会展中心体育场环梁大体积混凝土的施工技术和经验。