The manufacture of ADTO cast iron double coupler must meet the requirements of drawing approved by the state. And the raw material of scaffolding coupler should meet the mechanical property standard specified in KTH330-08 in GB9440. The double coupler is one of the most used scaffolding coupler which is mainly used to connect the standards and cross bar.

The production method of double coupler includes the hot pressing process of cover plate and middle part. The production method of cover plate can be concluded as follows:  

1.Heat the work blank after the steel plate is formed into work blank by the punching machine.

2.And then make the work blank to form the shape of the cover plate with the punching machine. 3.After cooling, insert the work piece into the punching machine to punch out the bolt hole. 4.Finally, place the work piece on the pouting machine, and it is formed by protruding each side of the opening.

Precautions before using

1. The length extension of standards using double coupler, the lap joint only can be used at the top, all other joint must be connected by butt joint coupler. The butt joint and the lap joint shall be conform to the following rules: the overlapping length should not less than 1 meters and shall be fixed with no less than 2 rotating fasteners. The distance from the edge of the cover plate of the end fasteners to the end of the bar shall be no less than 100mm. The joint couplers on the vertical bar should be staggered, and the joint of two adjacent vertical bars should not be set in the same place.

2. Appearance quality requirements of cross fasteners: fasteners with cracks, deformation or bolts with sliding wire are strictly forbidden to use.
3. The scaffolding tubes and scaffolding couplers used to erect the formwork system should be sample inspected before using. The quantity of sample inspection shall be subject to relevant regulations. The scaffolding tubes and scaffolding couplers which not pass the inspection or without the inspection can not be used on the project.

4. The removal of double coupler must be carried out step by step from top to bottom. It is strictly forbidden to work up and down simultaneously. The altitude difference of segments removal should not be greater than two steps. The formwork system with wall connecting part，during the dismantling, the connecting part shall be removed one by one with the supporting system. It is strictly forbidden to remove all or several connecting parts before removing the supporting part.

5. Discharging shall comply with the following regulations: it is strictly prohibited to throw scaffolding tubes or scaffolding couplers from high to the ground.During the use of the formwork system, the rod member shall not be removed arbitrarily. When there is an equipment foundation and pipe trench under or adjacent to the formwork system supporting foundation, it shall not be excavated during the use of the formwork system.

7. A horizontal cross bar must be set at the main node. The bar shall be fastened with cross fasteners and shall not be dismantled. The center distance between the two cross coupler of the main node should not be greater than 150mm.

As the tubular scaffolding with fastening parts is cheaper than other kinds of scaffolding system products and it is also one kind of scaffolding system used most in construction at present. However, because there are many parts used in the erection, standard operation and reasonable use are necessary in the process of construction to ensure the safety of construction.