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• Orbital welding may be used in applications where a tube or pipe to be welded cannot be rotated or where rotation of part is not practical.
• Orbital welding may be used in applications where access space restrictions limit physical size of welding device. Weld heads may be used in rows of boiler tubing where it would be difficult for a manual welder to use a welding torch or view weld joint.
• Many other reasons exist for use of orbital equipment over manual welding. Examples are applications where inspection of internal weld is not practical for each weld created. By making a sample weld coupon that passes certification, logic holds that if sample weld is acceptable, that successive welds created by an automatic machine with same input parameters should also be sound.
Industries and Applications for Orbital Welding
Aerospace: As noted earlier, aerospace industry was first industry to recognize requirement for orbital welding. The high-pressure systems of a single plane can have over 1,500 welded joints, all automatically created with orbital equipment.
Boiler Tube: Boiler tube installation and repairs offer a perfect application for orbital welding. Compact orbital weld heads can be clamped in place between rows of heat exchanger tubing where a manual welder would experience severe difficulty making repeatable welds.
Food, Dairy and Beverage Industries: The food, dairy and beverage industries require consistent full penetration welds on all weld joints. Most of these tubing / piping systems have schedules for cleaning and sterilization in place. For maximum piping system efficiency tubing must be as smooth as possible. Any pit, crevice, crack or incomplete weld joint can form a place for fluid inside tubing to be trapped and form a bacteria harbor.
Nuclear Piping: The nuclear industry with its severe operating environment and associated specifications for a high quality weld has long been an advocate of orbital welding.
Offshore Applications: Sub-sea hydraulic lines use materials whose properties can be altered during thermal changes that are normal with a weld cycle. Hydraulic joints welded with orbital equipment offer superior corrosion resistance and mechanical properties.
Pharmaceutical Industry: Pharmaceutical process lines and piping systems deliver high quality water to their processes. This requires high quality welds to ensure a source of water from tubes that is uncontaminated by bacteria, rust or other contaminant. Orbital welding ensures full penetration welds with no overheating occurring that could undermine corrosion resistance of final weld zone.
Semiconductor Industry: The semiconductor industry requires piping systems with extremely smooth internal surface finish in order to prevent contaminant buildup on tubing walls or weld joints. Once large enough, a build up of particulate, moisture or contaminant could release and ruin batch process.
Tube/Pipe Fittings, Valves and Regulators: Hydraulic lines and liquid and gas delivery systems all require tubing with connector fittings. Orbital systems provide a means to ensure high productivity of welding and improved weld quality. Sometimes tubing may be welded in place to a valve or regulator body. Here orbital weld head provides ability to produce high quality welds in applications with restricted access to weld joint.
A manual weld taken from an operating plant. This weld has defects that include lack-of- penetration, misalignment, a huge crevice, and discoloration due to poor ID purge. This weld would be considered unacceptable by any standard