时间：
2018
-
12
-
03
characteristic:Outer ring thread, multi-level line contact, strengthen to prevent external leakage, more convenient loading and unloading;Built-in three lips to strengthen the prevention of internal leakage;Automatic demoulding design to enhance service life;The multi-layered skeleton design enhances pressure resistance and challenges 10 kg of fluid impact;For the medium is dirty, strengthen the solid body to prevent the main lip from being damaged.