2019-11-09 - 标准号:GB/T 12234-2019中文标准名称:石油、天然气工业用螺柱连接阀盖的钢制闸阀英文标准名称:Bolted bonnet steel gate valves for petroleum and natural gas industries标
2019-11-06 - 标准号:GB/T 12234-2019中文标准名称:石油、天然气工业用螺柱连接阀盖的钢制闸阀英文标准名称:Bolted bonnet steel gate valves for petroleum and natural gas industries标