UHP 625: Precision Welding for Ultra High Purity Applications
Context & Need
In industries where the highest levels of cleanliness and precision are required—such as semiconductors, pharmaceuticals, biotechnology, aerospace, and clean energy—the integrity of welded joints is critical. Any contamination, oxidation, or structural defect can compromise the performance and reliability of complex systems, leading to costly failures or safety risks.
Traditional welding techniques, while effective in many applications, struggle to meet the stringent requirements of Ultra High Purity (UHP) welding. In environments where fluid transfer systems, gas distribution networks, or critical structural components must be completely free from impurities, even the smallest welding inconsistency can lead to operational issues.
The primary challenge lies in ensuring consistent, high-quality welds on small-diameter tubing and micro-fittings, often in confined spaces, while maintaining an inert atmosphere to prevent oxidation. Manufacturers in these sectors need a welding solution that guarantees precision, repeatability, and absolute purity—all while optimizing production efficiency and minimizing downtime.
Developed Solution
To meet the demanding requirements of Ultra High Purity (UHP) welding, the UHP 625 orbital welding head was designed as a compact, high-precision solution capable of performing automated, contamination-free welds on small-diameter tubes and micro-fittings. Its closed welding chamber ensures a controlled atmosphere, eliminating oxidation and maintaining the highest levels of purity.
With a modular design, integrated remote control, and precise speed regulation, the UHP 625 offers exceptional repeatability, flexibility, and ease of use, making it the ideal choice for critical industries.
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The UHP 625 is designed for applications requiring welding in tight spaces. With a width of only 70 mm and a height of 60 mm, it provides an extremely compact yet powerful solution. The unique drive motorization enables smooth and precise electrode rotation, ensuring a uniform weld bead around the tube. The clamping collets are engineered to provide firm but gentle tube fixation, preventing any deformation while maintaining perfect axial alignment.
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One of the key challenges in designing the UHP 625 was integrating a 70A TIG welding system within such a small enclosure. This high current is necessary to generate sufficient arc energy for deep penetration welding, despite the thin wall thickness of the tubes. To ensure electrical safety and reliability, the system incorporates high-frequency shielding to prevent electromagnetic interference, as well as advanced insulation materials to withstand extreme temperatures and electrical stress.
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Unlike larger welding heads that rely on liquid cooling, the UHP 625 uses a high-efficiency air-cooling system, a necessity for such a compact design. Given the high energy density generated within the welding chamber, cooling is a critical factor to prevent plastic insulators from melting and ensure continuous operation. The housing features strategically placed heat dissipation zones, and the airflow is carefully directed to maintain a stable operating temperature, even during intensive welding cycles.
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Precise electrode alignment is essential to achieving defect-free, high-purity welds. The UHP 625 features a return-to-home function, which automatically repositions the tungsten electrode to a predefined starting point. This ensures consistent arc ignition and eliminates human error in electrode positioning. Additionally, the electrode gear is interchangeable (available in ¼" and ½" variants) to accommodate different radial and axial clearance constraints in complex piping systems.
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For optimal arc stability, the welding circuit must create a clean and consistent electrical path from the negative pole (tungsten electrode) to the positive pole (workpiece). The UHP 625 is designed with precision-engineered clamping collets that not only secure the tubes but also serve as a controlled electrical contact point. This design minimizes electrical resistance variations, preventing arc instability and ensuring a smooth, even weld pool formation.
Results & Impact
The UHP 625 has redefined Ultra High Purity welding, delivering unmatched precision, reliability, and efficiency for industries where weld integrity is critical.
✅ Flawless Weld Purity – The closed chamber and controlled gas environment eliminate oxidation, ensuring perfectly clean, contamination-free welds.
✅ Boosted Productivity – Automated positioning and closed-loop speed control reduce defects, increase throughput, and minimize operator intervention.
✅ Continuous Performance – The advanced air-cooling system prevents overheating, enabling long welding cycles with minimal maintenance.
✅ Extreme Precision in Tight Spaces – Its compact, modular design allows for high-accuracy welding in complex tube networks.
✅ Enhanced Safety & Ease of Use – High-frequency shielding and ergonomic remote control ensure secure, high-current welding (up to 70A) with maximum operator comfort.
With unrivaled purity, efficiency, and durability, the UHP 625 is the ultimate solution for high-tech industries demanding perfection.
The projects and images presented on this site illustrate projects I contributed to during my previous professional experiences or projects completed with zaKraft. They aim to showcase my skills in design and project management. These machines are not offered for sale by zaKraft.