Weld inspection and non-destructive NDT tests
Orbital welding is an advanced and fully controlled automatic welding method in which the welding torch rotates 360 degrees. (Orbit perfect) rotates around the pipe or cylindrical part, while the part remains stationary.
- This technology has been developed to achieve uniform, repeatable quality without depending on the skill of the operator. Orbital welding is a key technology in industries with high quality requirements, which enables complete control of the welding process by eliminating the human variable, and has practically become an industry standard in sensitive projects.:Oil, gas and petrochemical industries
Pharmaceuticals and biotechnology
Food and dairy industries (Hygienic Welding)
Power plants and heat exchangers
Small to medium diameter stainless steel pipelines
Orbital welding is a specialized type of welding where the torch is mechanically operated through a 360-degree rotation in a continuous process (Two to 180 degrees or four to 45 degrees) It revolves around a static piece, like a tube.
In Orbital Welding which is one of the TIG processes (TIG) is, rotary welding is done by automatic torch, and all the movement of rotary torch, both in terms of filling and rotation and welding, is done fully automatically..
Orbital welding can be done with or without filler. welding Orbital is a type of welding that is controlled by a computer and the intervention of the operator in welding is zero, so that a uniform and error-free welding can always be achieved with quality And safety achieved high.
With the increasing need of advanced industries for connections with high reproducibility, uniform quality and minimal human error, traditional welding methods are no longer responsive to technical requirements.. Meanwhile, as an engineered and semi-automatic/automatic technology, orbital welding plays a key role in sensitive industries such as oil and gas, petrochemical, pharmaceutical, food, power plants, and semiconductors..
Orbital welding not only improves the metallurgical quality of the joint, but also enables precise control of process parameters, complete documentation and advanced inspection..
Orbital welding is a process in which the welding arc (Usually TIG/GTAW) It rotates 360 degrees around a pipe or joint with controlled speed and parameters, while the workpiece remains stationary. In this method, the hand movement of the welder is eliminated and the quality of the weld depends on the machine's engineered settings rather than individual skill..
The main components of the orbital welding system:
Smart power supply (Power Supply) Programmable
Orbital head (Open Head یا Closed Head)
Tungsten electrode with controlled geometry
Protective gas supply system (Argon / Helium Mix)
Digital controller with the possibility of data recording (Data Logging)
Types of orbital welding
1. Orbital with closed head (Closed Head)
Suitable for small diameter pipes and clean environments (Clean Room)
No filler metal
Widely used in pharmaceutical and semiconductor industries
2. Orbital with open head (Open Head)
Suitable for larger diameters
The possibility of using filler wire
Common in oil, gas and power plant industries
Technical and engineering advantages
✅ Very high repeatability
Accurate control of input heat (Heat Input)
✅ حداقل HAZ و کاهش تنشهای پسماند
✅ کاهش آلودگی و اکسیداسیون ریشه جوش
✅ قابلیت مستندسازی کامل فرآیند جوش
نکات متالورژیکی خاص در جوشکاری اوربیتال:
- توزیع یکنواخت حرارت باعث ریزدانگی ساختار جوش
Reducing the possibility of Hot Cracking in alloy steels
Better penetration control (Penetration) In thin tubes
Excellent performance in welding duplex and super duplex stainless steels
Inspection and quality control in orbital welding
One of the main strengths of this method is the ability to control and monitor quality in an engineered way.
1. In-process control (In-Process Monitoring)
Record voltage, current, rotation speed and time
Detection of arc instability at the moment
Traceability for each welding pass
2. Non-destructive inspections (NDT)
VT (Detailed visual inspection) With a borascope
Digital RT to check penetration and porosity
Advanced UT (PAUT/TOFD) At higher diameters
Leak Test in pharmaceutical and food industries
3. Metallurgical and mechanical tests
Macro H (Macro Etch)
Tough test (HV)
Investigation of HAZ structure
Tensile and bending test (In PQR)
Important related standards
ASME Section IX
ISO 15614
ISO 9606
AWS D18 (Special for health industries)
Special and less mentioned applications of the orbital welder:
Ultra pure gas transmission lines (Ultra High Purity)
Vacuum systems in space industries
Hydrogen fuel lines
Precision heat exchangers