For the valve with the metal to metal seal,there is grease injector outside of it,grease gets into the sealing face through the injector and the seat ring to have the valve up to null leak.

• 金属对金属密封的阀门，阀体外部设有注油脂结构，油脂通过注脂器、阀座进入阀门密封面，使阀门达到零泄漏。