Cleaning and Inspection Challenges No.3
Author: Mike Watson, Managing Director, Tube Tech
Following a recent survey of refinery operators from across the world Tube Tech have compiled the Top 10 cleaning and inspection challenges faced by the refining industry.
As a world leading specialist industrial cleaning contractor Tube Tech have solved some of the refining and petrochemical sectors most difficult cleaning challenges. Tube Tech asked over 2500 refinery operators to complete their survey and the Top 10 cleaning and inspection challenges were developed as result of the survey feedback.
Below is the 3rd most common cleaning and inspection challenge faced by the refining sector.
No 3 Cleaning for IRIS Inspection
The advantages of the Internal Rotational Inspection System (IRIS) inspection technique (an ultrasonic immersion pulse echo technique) is that it is very accurate, it is sensitive, both ferromagnetic and non-ferromagnetic tubes can be inspected, a 3 dimensional picture of defects can be provided and the results of the inspection are easier to interpret than those provided by other inspection techniques. All sounding very positive but (and there is always a ‘but’ when something sounds this good) for IRIS inspection tubes must be very clean. All other inspection techniques such as Eddy Current, Remote Field and Magnetic Flux Leakage, are able to tolerate some degree of scaling. For IRIS inspection to be successful the tubes must be cleaned virtually down to the bare metal.
Many refinery operators/maintenance personnel will be familiar with the following scenario:
- Cleaning contractor ‘cleans’ heat exchanger ready for IRIS inspection.
- IRIS inspector unable to inspect due to tubes not being clean enough
- Cleaning contractor called back to ‘re-clean’ tubes to a higher standard
- IRIS inspector recalled to re-inspect tubes.
This scenario is happening time and time again on refineries across the world and the financial impact is not only the costs of the cleaning contractor and the inspection company but the additional downtime incurred.
Cleaning to a standard ready for IRIS inspection is categorised as ‘enhanced’ cleaning at Tube Tech as the company appreciates how crucial it is to get tubes cleaned to IRIS standard the first time.
Standard cleaning contractors are often only able to clean to at best production standard using traditional high pressure water jetting methods. Deposits can vary so the same technique may not be effective on every tube with a heat exchanger/VCFE (Texas Tower) etc. To achieve a standard for IRIS inspection tubes need to be cleaned and the highly polished.
Tube Tech’s Enhanced Tube Cleaning service achieves tube cleanliness standards suitable for IRIS inspection no matter the scale or deposit within the tubes. Tube Tech’s bespoke remote control IRIS standard cleaning technology is used to drill, descale, polish and inspect tubes via even the smallest diameter man way / nozzle. Tube Tech is also able to access man ways/nozzles located on the side of the fully welded header, at right angles to tube sheet to achieve a bare metal clean.
A North American Turnaround Block Coordinator states that: “When Tube Tech clean for IRIS testing they do it the first time and there is no rework then there is no added cost whereas on site here in the past we had to clean and re-clean and re-clean and then it’s not only the cost of the cleaning company it’s the cost of all the other resources that are supporting that activity. So it all compounds.” Tube Tech is proud to offer a guaranteed. Enhanced Tube Cleaning service ensuring tube bore cleanliness suitable for IRIS inspection.