In the high rise construction, there is a large demand of scaffoldings with higher requirements and complicated technical standards, which imposes a

potential influence on the staff safety, project quality, the construction speed and the cost of the construction project. It needs specialized staff to

design and calculate the scaffolding drawings.

The couplers are the devices to connect the scaffolding steel tubes, which can be categorized into 3 kinds according to the types and functions: the

right angular couplers, the swivel couplers or the adjustable scaffolding coupler and the butting couplers. The right angular couplers are to connect

two orthogonal crossing tubes with an allowed loads of 12.5KN; the swivel couplers are to connect any two crossing tubes with an allowable loads of

12.5KN and the butting couplers are to butting connect tubes with an allowable loads of 25KN. All the couplers shall comply with the requirements in

the” steel tube scaffoldings”. When the torque force of the couplers bolt is 20NM, there shall be no damage or crack in the couplers. Before the real

application, the couplers shall be checked and inspected to see if there is any fracture, deformation or slip between the nuts and the tubes.