短语词组短语butt -weld flange 焊法兰plain butt -weld 对焊flash butt -weld 闪光对接焊缝Butt -weld Machine 亚焊机continuous butt -weld mill 连续式炉焊管机组furnace butt -weld pipe 炉焊管 返回 butt-weld