EHE's Integral Mandrel Impeders provide the most economical & efficient method of I.D. scarfing or rolling with induction welding of tubing up to 3" in diameter.
These impeders use an internal stainless steel tie rod or mandrel which is threaded & pinned to heavy duty hexagonal bushings at both ends. The mandrel is surrounded by either a single cylindrical ferrite tube, or a cluster of smaller diameter ferrite rods. The entire assembly is enclosed in a high temperature non metallic outer cover which protects the ferrite & directs the coolant. The hexagonal bushings have internal threads (either metric or SAE) and setscrews to enable the impeder to be locked to the tow rod. Alternatively, jam nuts or lock nuts can be used.
Most I.D. scarfing systems do not allow sufficient space for ferrite, with the result that welding efficiency is reduced & excessive heating of the tow rod can occur. EHE's Integral Mandrel Impeders provide the highest possible efficiency, combined with the mechanical stability required for quality I.D. flash control.
These impeders also greatly reduce the cost & complexity of the tow rod. Since it is only necessary to use non magnetic material for those portions of the tow rod that are in the vicinity of the welding coil, the entire tow rod can be fabricated from carbon steel. This is much less expensive and often stronger than the commonly used austenitic stainless steel used for most tow rods.
To view the chart of our standard Integral Mandrel impeders click the chart on the right or just click here