In the period of 2014 – 2016, LBNiW successfully delivered a comprehensive non-destructive testing programme for Bilfinger Power Systems during the installation of two steam boilers at Veolia’s combined heat and power plant EC3-Łódź.

A new project and the new partnership.

Because this was the first order from Babcock Borsig Steinmüller (BBS) the supplier audit was performed so as to verify if our internal processes meet their quality standard. BBS’s quality assurance representatives visited us in Poland in order to check if we have suitably qualified staff, the right equipment that is appropriately calibrated and maintained, to review our testing procedures and finally if our reporting practices guarantee accurate and reliable results. After BBS established that LBNiW is a professional ndt contractor which is technically competent for the project we could start the work.

LBNiW executed a comprehensive ndt programme during the installation of two steam boilers at Veolia’s CHP plant EC3-Łódź. Testing has been performed according to EN 12952-6, EN 13480-5, and project’s ITP. The conventional NDT methods were utilized i.e: VT, RT, UT, MT, HT, and PMI.

LBNiW managed two contracts on this project, one directly with Bilfinger Babcock Borsig Steinmüller (BBS) and  one with BBS’s main subcontractor – Bilfinger Duro Dakovic Montaza (DDM) which was responsible for the installation of pressure parts of the boilers. In total, more than 7,000 inspection hours were used for the comprehensive service delivery.

LBNiW’s main commitment with BBS was to provide examinations and diagnostic measurements on the old part of the installations (old sections of steam pipelines and feedwater lines) that were not going to be replaced in the course of the project but all newly installed pipelines were going to be connected to. Our responsibility was to perform 100% weld integrity testing by UT and MT. Additionally, all bends on the steam pipelines were UT and MT tested, many ultrasonic thickness measurements were taken, and a couple of metallurgical replicas were carried out in order to evaluate material microstructure deterioration due to creep damage. Some of that work we subcontracted to our business partner whose expertise is an in-service inspection of boiler components. All examinations were performed according to the inspection plan provided by BBS. Additionally, we performed various ad-hoc assignments from BBS that included hardness testing, positive material identification, UT, RT, MT and VT of various components.

The vast majority of our work was performed under the contract with Bilfinger Duro Dakovic Montaza during the installation of the pressure parts of boilers K6 and K9. We performed EN 12952-6 compliant weld integrity testing of boiler proper components and EN 13480-5 compliant testing of welds on pipelines external to the boilers. The testing was limited to site welding only and its extent would vary from 10% to 100%. The project team comprised of 7 specialists using the common non-destructive testing techniques: RT, UT, MT, HT, PMI.

We performed radiographic testing of 4700+ welds with Selenium (Se75) sources. It was quite a challenge to keep up with the radiographic testing of welds because of reduced RT window. The installation was performed on two 10-hours shifts for 6 days a week which left only 4 hours a day plus Sundays for inspections. The conditions got even more complicated during the peak period when the installation was performed on both boilers simultaneously also on Sundays. These boilers are located next to each other, consequently, the work of two radiographic teams had to be coordinated so as they wouldn’t interfere with each other’s work.

LBNiW’s highly skilled inspectors managed to successfully complete all the radiographic testing and meet all the deadlines, despite the obstacles. Regular radiographic testing was performed 6 days a week and additionally there was one team working on Sundays (whenever possible) to clear any backlog that would accumulate from weekdays.

During the day LBNiW’s inspectors would perform UT, MT, field hardness testing and PMI. Our service delivery included:

• UT of 1100+ welds
• MT of 1400+ welds
• HT of 1200+ welds
• PMI 200+ inspection points

We assigned two specialists with a broad spectrum of qualifications to perform daily tasks required by the project. All tests have been performed according to EN 12952-6 or EN 13480-5 and project’s test plan.

Magnetic particle testing and field hardness testing were performed on all PWHT joints. Hardness testing by ultrasonic contact impedance (UCI) method was used. Our hardness testing specialists are well-trained and experienced with the UCI method, additionally, our HT procedure takes into account additional considerations for hardness measurements on the P91 material grade that was used on superheaters and main steam pipes.

Ultrasonic testing was performed on welds above 8mm thick. 100% of welds on live steam lines were UT tested. The scope of UT testing on other piping systems would vary from 10% to 100% depending on the applicable EN norms or project’s test plan.

Positive material identification PMI on welds was primarily used to confirm that proper filler metals were used for critical welds. Random PMI testing was conducted on the superheaters and 100% verification on the main steam pipes.

Ultrasonic testing of welds was widely used on pipes with diameters ≥ DN100.