M. J. Patel (I) Ltd.

Masjid Bunder, Mumbai, Maharashtra

For pipes or tubes size 4 inch (10.2mm) OD and below, strip is fed into a set of forming rolls which consists of horizontal and vertical rollers so placed as to gradually from the flat strip in to a tube which is then allowed to pass the welding electrodes. The electrodes are copper disks connected to the secondary of a revolving transformer assembly.

The copper disk electrodes make contact on each side of the seam and temperature is raised to the welding point. Outside flash is removed by a cutting tool as the tube leaves the electrodes, inside flash is removed either by an air hammer or by passing a mandnel through the welded tube after the tube has been cooled. This is termed as Electric Resistance welded or ERW tube/pipe. If this ERW is being drawn further to get desired size of tubes or pipes, in cold condition is called as Cold Drawn welded or CDW.

In Boiler tubes, when water is evaporated to steam are called Steam Generating Tubes. These Tubes also form the Walls of the Boiler and are hence called Water Walls or Water Wall Panels. These Tubes have very complicated shapes to allow Inspection openings and burner throats and fabrication require intricate binding on CNC programmable bending Machines and checking on 3D layouts.

M.J.Patel can supply these tubes with ends swaged/reduced to smaller diameters or expanded to higher diameters. Ends can be supplied fully ground and annealed to facilitate Expansion or bevelled to weld to Header Stubs. The Water Wall Panels are High frequency tube to tube welded and then bent on Panel Bending Machines or the Gas tight panel can be made by welding Fins to tubes using Low Temperature Automatic Welding Machines using CO₂and Filler wires.