HG/T 21530-2014
带颈平焊法兰手孔
Slip on flange handholes
2014-07-09
HG/T 21531-2014
带颈对焊法兰手孔
Welding neck flange handholes
2014-07-09
HG/T 21532-2014
回转盖带颈对焊法兰手孔
Welding neck flange handholes with hinged cover
2014-07-09
HG/T 21517-2014
回转盖带颈平焊法兰人孔
Slip on flange manholes with hinged cover
2014-07-09
HG/T 21523-2014
水平吊盖带颈平焊法兰人孔
Slip on flange manholes with davit to horizontal cover
2014-07-09
HG/T 21520-2014
垂直吊盖带颈平焊法兰人孔
Slip on flange manholes with davit to vertical cover
2014-07-09