connection of portal frame
high frame portal crane
light-weighted steel portal frame
portal frame
桥门构架
门架式支架
龙门架
桥门架
门式刚架
门框状构架
支座
门式框架
厂房
门形框架
门式钢架
门架
portal frame with cable - strut
Portal frame with straight members
portal frame with tapered members
superhigh and large portal frame
titled column portal frame
cavernous portal vein portal vein cavernous transf
5 t X-Y high security hoist