Automated welding equipment manufac- turer Devine Machines has designed and installed its biggest strip clamper to date for local stainless steel pipe manufacturer Euro Steel Pipe.

Devine Machines engineering manager Liam Devine says the company began custom- manufacturing the 6 m strip clamper, complete with beam and welding carriage, in November last year and installed it at the client’s premises in Wadeville, Johannesburg, in May.

The strip clamper automatically welds pipes of any material, with inside diameters of 300 mm, outside diameters of up to 2 m and lengths of up to 6 m, making it the largest machine of its kind. It can handle pipes weighing up to 5 t.

“What makes the machine different is the range and size of the pipes that it can weld. It has been custom-designed to meet the steel pipe manufacturer’s requirements and is versatile with regard to the ease in which different pipe sizes can be accommodated,” Devine explains.

The machine has a clamping force of 4 000 N a side and a carriage travel speed of between 150 mm/min and 1 500 mm/min.

The machine consists of a round mandrel, equipped with a water-cooled copper backup bar. The copper bar has a groove to accommodate the inside weld in the pipe. The pipe is placed over this mandrel and two rows of pneumatically operated and independently controlled copper-tipped clamping fingers secure the pipe onto the backup bar.

Devine illustrates that the clamping fingers are mounted on the upper part of the clamp structure, which is high enough above the floor to allow even a 2-m-diameter pipe to be loaded into the machine. One end of the mandrel is held by opening a latch arrangement to allow for the loading and unloading of pipes in and out of the machine. The latch is interlocked with the fingers so that they cannot be actuated while the latched end is open.

A set of rails is mounted to the floor below the machine. Two height-adjustable motorised trolleys run along the rails, which assist with the loading and unloading of the pipes onto the machine.

“A submerged arc welding head from welding company Lincoln Electric is mounted to a carriage that runs on a machined beam, mounted above and behind the clamping area. It has a motorised electrical slide to adjust the height of the welding nozzle and to raise the welding head out of the way when the fingers are unclamped. “The carriage can be declutched and moved by hand along the beam, if required,” Devine says.

He hopes that the machine enables Euro Steel Pipe to increase its output and the quality of the welded pipes it produces.

Further, Devine says this installation should demonstrate to the welding automation industry that Devine Machines designs and manufactures high-quality machines.