The automatic end finishing, annealing and u-bending transfer machine is designed to complete all final manufacturing operations for tubular water heater heating elements, delivering a U-shaped component that is fully tested and ready for assembly.

The machine is divided into two synchronized processing sections, connected by a transfer system that automatically moves each heating element throughout the entire production cycle.

First section: end preparation and annealing

• Automatic loading unit: a mechanical arm picks each element from a container and places it on the walking-beam
• Electric spot annealing unit: passes current through the element and then water-quenches it, dropping its temperature as fast as possible; this localized annealing lets the element be bent effectively without cracking at the bend
• Plug extraction unit: removes the plastic plug used for filling and rolling the element, with pre-heating to ease extraction: particularly valuable for threaded pins or plugs with a tight interference fit, where the plug is otherwise hard to pull
• Pin cut-to-length unit: crops the terminal pin to the required length
• Chamfering unit: chamfers the pin end by roll-forming, for smooth pins
• Linishing unit: sands the outer surface at the worked end to prepare it for subsequent welding or brazing

Second section: bending and testing

• U-bending unit: bends the element into a U, with integrated centering that keeps both legs correctly aligned
• Hydraulic squeezing unit: squeezes the bend to reduce its radius, allowing tighter center-to-center spacing between the bent element’s legs
• Pressing unit: re-compacts the oxide layer in the bend zone, which may have cracked during bending
• Electrical testing unit: performs dielectric strength (hi-pot) and ohmic value tests
• Automatic unloading unit with scrap sorting: unloads finished elements and separates out any rejects automatically