Boiler Tube Inspection

TesTex provides specialised inspections for Water Tube and Fire Tube boilers of all sizes. For Generating Banks in Drum-to-Drum Boilers, we provide full-length tube inspections that can detect and quantify flaws in the straight and bend sections of the Boiler Tubing. We can conduct this test from the Mud Drum or Steam Drum. For the inspection of Boiler Generating Banks, we use the TesTex Eagle Plus Single and Multichannel Remote Field Electromagnetic Technique (RFET) System.

drum-to-drum inspection

For the Furnace or Waterwall tubes in larger Industrial & Utility Boilers, we provide Boiler Waterwall Scanning services. This service detects ID or OD flaws on the hot-side half of the tube. To gain access to these areas, we can work from hard scaffolding or swing staging. In gas burning boilers, no surface preparation is needed for this service. The same is true for most oil burning units. If a boiler burns coal, many times a quality high-pressure water blast is all that is necessary. For the inspection of the waterwalls, we use the TesTex TS-2000 Tube Scanning system based on Low Frequency Electromagnetic Technique (LFET). Our TesTex LFET technology scans approx. 120 degrees of the tube circumference with a single pass of the LFET scanner. Any flaw indications (or areas that we cannot scan due to tube bends, welds, viewports, etc.) are proved-up using Ultrasonics.

TesTex also provides O.D. scanning services for the Super Heater and Reheater areas of boilers, and sometimes even the Economisers. This service also employs the TesTex TS-2000 Tube Scanning System.

TesTex also offer IRIS Ultrasonic Testing for Boiler Generating Banks as a back-up method or the primary method of inspection along with Video Borescoping Services.
We can also inspect Tubular Air Heaters when present on certain boilers.

Horizontal Reheater Inspection – the TS-2000 is used to scan reheater tubing in utility boilers. The TS-2000 uses a contoured scanner that is customised for the specific tube OD.

The scanner is very thin, allowing placement onto the tubes, which are tightly stacked with minimal spacing. The scanner is manually moved along the tube wall to scan for defects in the tube as it passes directly over the tube surface. Typical defects found on reheater tubes are pitting and corrosion due to water settlement. The tubes are not required to be cleaned to the level necessary for ultrasonic thickness (UT) testing. A modest uniform scale will produce excellent results. Non-uniform scale is undesirable as it creates scanner lift-off. The TS-2000 uses no couplant and can detect small pits that can be difficult to identify with ultrasonics. Tube sizes tested range from 1/2″ OD to 4″ OD.

Superheater Pendant / Economiser Inspection – Again, the TS-2000 can be used to manually scan superheater bends in utility boilers. The scanner typically tests approximately 18″ to 24″ along the extrados of the bend to detect ID corrosion or erosion. A low profile magnetic crawler can be utilised as an option with the TS-2000 to automate the scanning process for superheater bends. The EPRI funded crawler has a maximum height of 50mm and can be utilised on tubes that cannot be scanned manually. The tubes are not required to be cleaned to the level necessary for ultrasonic thickness (UT) testing.

2619-02 – Photos of screen wall tubes, Failure – External corrosion – thin wall – rupture.

Screen wall tube failure

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screen wall tube failure close up

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Boiler tube inspection failures