In order to prevent mishaps with the union nut, slide it (smallest bore first) over the pipe or nipple and flange hub (when flanging) before making the joint to the end connector.

• 为了防止与管接螺母相关的事故，在连接到端口连接件之前，先将其(最小的内径朝前)滑入管道或管嘴和法兰毂(当法兰连接时)上。