10 spherically dished head 球冠形封头 11 floating head cover 浮头盖 12 single box packed floating tubesheet 单填料函式滑动管板 13 packing gland 填料压盖 14 packing 填料 15 packing box 填料函 16 weep hole 泄漏孔，检查孔 17 lantern ...