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.