In coupler-type steel tube scaffolds, couplers play the core role of connecting tubes and transferring loads. The common types of couplers include right-angle couplers, swivel couplers, and sleeve couplers, which are used for perpendicular intersections, intersections at any angle, and butt connections of steel tubes, respectively. The quality of couplers directly affects the connection rigidity and overall stability of scaffold joints.

Qualified couplers should have sufficient strength and good casting quality, with complete sets of bolts, nuts, and washers, smooth threaded connections, and be free from cracks, blowholes, and obvious burrs. During installation, the tightening torque of coupler bolts should be controlled within a specified range: too loose may result in insecure connections and joint slippage, while too tight may damage the steel tubes or threads. Standard practice requires quantitative tightening using a torque wrench, with spot-check re-tightening during acceptance inspections.

In daily use, couplers are consumable turnover items and should be regularly inspected for deformation, rust, and thread stripping. Unqualified items should be replaced promptly. Paying attention to the selection and maintenance of couplers is an important part of improving scaffold safety.