Normal flange-bolt assembly in top holes of the valve flange requires bolt insertion through the companion flange with nuts secured on Swing Check flange side.

• 阀门法兰顶部螺栓孔的法兰螺栓组装通常要求穿过配对法兰的插入螺栓要用螺母紧固在旋启式止回阀法兰一侧上。