Ultra high purity heads for joining tubes, micro-fittings, fittings and accessories Perfectly adapted for joining tubes, fittings and accessories out of stainless steel, high alloy materials and titanium. The head clamps on both sides of the weld joint and forms a closed chamber for the shielding gas and the welding arc. During welding, the head body remains stationary, the electrode gear and tungsten electrode rotate around the tube. Fixture blocks for micro-fittings and fittings without tack welding. Narrow weld head profile. Unique features • Compatible for work with all series of Polysoude power sources. • High purity gas circuit to avoid particle emission and oxidation. • Modular concept: unique drive handle; three electrode gear modules ¼" ; ½" ; 1 1/3"; removable clamping cassettes. • Non symmetrical design for welding of fittings with short stick-out. • Titanium clamping cassettes (UHP 250-2 and 500-2) or flexible Tube Clamp Inserts – TCI's™ (UHP 1500-2) to comply with standard O.D.'s tolerances and • hygienic / high purity requirements. • Narrow weld head profile for use in areas with constrained radial and axial • clearance. • Closed loop regulation to ensure precise, constant or pulsed welding speed. • Encoder for position based control of the welding program. • Return-to-home feature: the electrode gear automatically returns to its loading position.