Home / Standards / GBT 3452.4-2020 GBT 3452.4-2020 O-ring rubber seals for hydraulic and pneumatic applications — Part 4: Anti-extrusion rings 液压气动用O形橡胶密封圈 第4部分:抗挤压环 Standard Type GBT ICS N/A CCS N/A Status N/A Issue Date N/A Implementation N/A Responsible Dept N/A Drafting Unit N/A