Welded Pipe, Tube, & Conduit
Temperature Control for Welded Pipe
Williamson provides accurate temperature feedback from welded seam to protective coating, ensuring optimal process conditions and advanced quality control.
Welded Seam
Application Overview
Flat strip is fed into a welding station, where it is shaped into a tube, & an electrical current is induced along the edges of the strip. This process heats the edges, allowing them to be forged into a welded seam when pressed together by the pressure rolls.
The peak temperature, found at the apex of the V, where the two heated edges converge to form the welded seam, is a crucial process control parameter used to control line speed & adjust inductor power. The integrity of a welded seam relies on maintaining a consistent temperature at this apex. Uneven heating can undermine the weld’s quality, potentially weakening tubular products & increasing the risk of leaks in pipe products.
The small target, tight temperature windows, and possible steam interference are common temperature measurement challenges associated with the welded seam. Williamson’s Dual-Wavelength DW Pyrometers provide unequalled accuracy & repeatability for welded seam temperature measurements.
Pyrometer Benefits
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Ensures Quality Welds
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Reduces Scrap
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Optimizes Line Speed
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Improves Start-Up Efficiency
Advantages of Williamson's Wavelength Technology
- Dual-Wavelength (DW) Technology self-aligns to the crucial target on the welded seam.
- Produces consistent, accurate, & repeatable temperature readings of the small wandering target
- Carefully selected wavelength sets overcome optical interferences & obstructions associated with this measurement
Annealing: Full Body & Welded Seam
Application Overview
Metal inside the welded seam cools rapidly, causing it to become hard & brittle which ultimately can result in the propagation of cracks along the seam. Annealing the welded seam provides flex & strength, ensuring structural integrity. There are two primary methods of weld annealing: fully body annealing which heats the enture pipe/tube & weld annealing which only heats the welded seam. Inadequate annealing temperatures/temperatures outside of a relatively narrow temperature window result in undesirable mechanical properties. Excessive temperatures during the annealing process indicate process inefficiencies.
The small target, emissivity variation, surface oxidation, & scale are common temperature measurement challenges associated with this annealing process. Williamson’s Dual-Wavelength DW and Multi-Wavelength MW Pyrometers provide unequalled accuracy & reliability for welded seam and full body annealing temperature measurements.
Pyrometer Benefits
- Ensures Strong, Flexible, & Durable Weld
- Provides a quality assurance metric for customers
- Optimizes Annealing Process by decreasing power utlilization or by increasing line speeds
Williamson Wavelength Technology Advantages
Common Steel Alloys: Dual-Wavelength DW
- 20x less sensitive to surface oxidation & scale compared to SW & TC pyrometers
- Self-aligns to the hot welded seam
- Corrects for emissivity variation, surface oxidation, & scale
Stainless Steel, Superalloys, & Advanced Strength Alloys: Multi-Wavelength MW
- Corrects for non-greybody emissivity variation associated w/ stainless steels, high strength steels, & superalloys
- 10 Wavelength Set compensates for surface changes associated w/ stainless steel & superalloys
- 20 Wavelength Set compensates for surface changes associated w/ Gen. 3 Advanced High Strength Alloys
Coating Processes: Paint, Primer, & Hot-Dip Zinc
Application Overview
Once fully formed, tubes may undergo a coating process, such as hot-dip zinc or paint & primer. These coatings serve various protective & functional purposes. Temperature plays a vital role in each of these coating processes.
Hot-Dip Zinc: Pipe or Tube temperature as it enters the hot-dip coating process is a vital quality control parameter. The steel pipe or tube must be adequately preheated for to ensure full adhesion of the zinc coating to the steel base metal. Partial adhesion to the pipe or tube results in mechanical defects & rejected products. Significant emissivity variation associated with the preheated tube demands the use of Williamson’s Multi- Wavelength (MW) Pyrometers.
Paint & Primer: For the primer & paint coatings to cure correctly, the pipe or tube must be preheated. This coating creates an optical interference that disrupts pipe/tube temperature detection. Williamson’s Short Wavelength (SW) & Specialty Wavelength (SP) pyrometers utilize carefully selected narrowband wavelengths to accurately measure the temperature of primed & painted steel pipes & tubes.
Pyrometer Benefits
- Ensures Primer & Paint Coatings Completely Cure
- Guarantees Proper Adhesion of Molten Coating to The Pipe/Tube
- Helps Achieve Desired Surface Characteristics & Prevents Surface Marring During Transport
- Eliminates Mechanical Abnormalities Caused by Inadequate Pipe/Tube Temperatures
Advantages of Williamson Wavelength Technology
Primed Surface
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Short Wavelength (SW) maximizes temperature sensitivity while minimizing sensitivity to emissivity variation
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SW-2A utilizes the shortest wavelength on the market to view through primer regardless of thickness
Painted Surface
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Specialty wavelength technology (SP-PG) uses a narrow-band wavelength where coatings are most opaque & non-reflective, making the emissivity high & stable, regardless of coating type, color, gloss, or thickness
Hot-Dip Zinc
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Multi-wavelength (MW) technology automatically compensates non-greybody emissivity variation associated w/ zinc-coated steel pipe/tube
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20 – Wavelength Set compensates for surface changes associated w/ Gen. 3 Advanced High-Strength Alloys
Consult With One of Williamson’s Temperature Experts
We would love to discuss your temperature measurement application with you.
