Project Description

Montes del Plata Pulp Mill Uruguay 2012-2014.


The US$1.9 billion Montes del Plata pulp mill is one of the world’s largest and most modern facilities of this type. Construction finished in Q2 2014.

Proven partners undertake a new challenge together

When LBNiW successfully delivered NDT services for the previous large-scale project in Uruguay in 2007, it initiated a good working relationship with Butting GmbH & Co KG. So, it was logical for Butting to contract LBNiW for the next grand project in South America. LBNiW had proven its ability in large-scale projects and has the resources to assemble the right team to manage the inspection workflow.
Montes del Plata project was the second major order for non-destructive testing services LBNiW received from pulp and paper industry. In the period  of  2012 – 2014,  LBNiW  played a key  role in the weld integrity testing during the pulp mill construction.

Prefabrication – Germany

3 months before our first team arrived in Uruguay LBNiW commenced x-ray radiography on prefabricated pipeline elements that were assembled in Germany and were subsequently shipped to Punta Pereira. LBNiW assigned one team of RT inspectors with equipment to perform daily inspections of weld production in Butting’s prefabrication shop.

Mechanical erection – Punta Pereira Uruguay

The first team arrived at Punta Pereira in June 2012 and was mainly responsible for preparing the stage for the others.

To begin with, all employee certificates and testing procedures were submitted to ANDRITZ’s quality assurance department for the review and approval. International group ANDRITZ was a technology supplier to MdP pulp mill.

In the meantime, our team was engaged with the ‘housekeeping’. Providing services overseas is a logistically challenging task that our team handled efficiently. It involved dealing with foreign authorities in order to obtain necessary government permits, satellite office set-up, managing international shipments, organizing work permits, visas, car rentals, employee housing and etc. Experience gained during Fray Bentos project was invaluable especially with reference to obtaining the permit for utilizing ionizing radiation in Uruguay. We already knew the process and the permit had to be renewed only. Our radiation protection officer could apply for the permit renewal long before our specialists appeared on the site.

Once the remaining teams arrived the inspection work could start with a full force. Our project team consisted of 10 specialists with a broad mix of inspector qualifications so they could handle the wide range of inspection duties required by this project.

Project scope

Similarly, like during the previous project in Uruguay our scope of work has substantially increased after arrival on the site. In November of 2012 Austrian KRESTA Anlagenbau GesmbH Nfg & Co KG asked LBNiW to take over their inspection program from the local NDT contractor that was falling behind with the inspection duties causing delays.

We had to manage a very heavy workload in order to clear the backlog and keep up with the very challenging inspection schedule. We worked 6 days a week, 10 hours a day throughout 2013.


LBNiW was involved in the weld integrity inspection on most of MdP installations.

More than 35,000 inspection hours were accumulated

1. Fiber Line

LBNiW performed radiographic and ultrasonic testing of over 1000 welds on fiber line according to EN 13480-5. Tested lines belonged to all PED classifications, were fabricated in various material grades (carbon steel, stainless steel, duplex, titanium) and covered diameters from DN25 to DN1800.

The combination of RT, UT, PT, VT, MT and vacuum box testing was utilized for providing EN-14015 compliant welds inspection of 11 storage tanks with capacity ranging from 500m3 to 13500m3. Additionally, very extensive (approx. 15km of welds) leak testing/penetrant testing was performed on stainless steel sheet lining of the carbon steel storage tanks.

Finally, we carried out EN 13445-5 compliant NDT inspections of 2 PED class IV duplex pressure vessels with a capacity of 900m3 and 1600m3. These inspections involved a 100% x-ray of all butt welds (over 1,2km of welds) and extensive use of penetrant testing.


View of the fiber line at MdP. Weld integrity of its key components verified by non-destructive testing from LBNiW. Our company provided code compliant NDT inspection of pressure piping welds according to EN 13480-5, storage tanks according to EN 14015, and pressure vessels according to EN 13445-5. All common NDT methods were utilized i.e: VT, RT, UT, PT, MT, and vacuum box testing.

2. Drying Plant

LBNiW provided radiographic and ultrasonic testing of over 800 welds on drying plant according to EN 13480-5 in various material grades and of various diameters.

The combination of RT, PT, VT, and vacuum box testing was utilized for providing EN-14015 compliant inspection of 2 large storage tanks with the capacity of 3500m3 each and 6 smaller tanks.


Some pipelines at drying plant.

3. Pipe Bridge

Pipe bridge at MdP pulp mill stretches for 4km throughout the site running multiple pipelines connecting all main plants of the mill. LBNiW was responsible for performing  non-destructive testing of pipelines run on the bridges according to EN 13480-5 and project’s test plan. Depending on pipeline PED category the inspection scope could vary from 5% to 100% of welds.

We x-rayed over 1200 welds on the pipe bridge. Additionally, we tested 300+ welds with UT and many others with PT (mainly branch connections).


One of the pipe bridge section.

4. Evaporation Plant

On evaporation plant, LBNiW service delivery covered a complete non-destructive weld examination of storage tanks and its large PED class 4 duplex pressure vessel. We tested 4 largest storage tanks on evaporation plant according to EN 14015 using RT, MT, PT, VT, UT and vacuum box.

The pressure vessel on evaporation plant has the capacity of 1400m3 and about 60% of its butt welds were x-rayed by us (about 400m of welds) according to EN 13445-5. Additionally, we performed all surface tests on this pressure vessel that were required by the standard.

Our involvement with weld inspection of piping on evaporation plant was limited. We x-rayed about 300 welds of various diameters.


View of the evaporation plant.

5. White Liquor Plant (WLP)

On WLP, LBNiW’s commitment was to carry out a comprehensive code compliant non-destructive testing of 13 storage tanks with a total capacity of 28,000m3 and inspection of field welds of the lime kiln according to project’s inspection plan.

A combination of all conventional non-destructive testing techniques was used to verify the weld integrity of the storage tanks according to EN 14015. A 100% ultrasonic testing and magnetic particle testing of the six circumferential field welds of the lime kiln were performed. The lime kiln at MdP is massive 100m long, 6m diameter and has a wall thickness ranging from 32mm-40mm.


Storage tanks at white liquor plant.

6-7. Turbine Island & Boiler House

Unlike the other sub-plants where LBNiW played a key role in weld integrity testing, our involvement in turbine generators building and boiler house was limited to non-core piping systems according to EN 13480-5. We assumed a role of supporting NDT contractor next to Finish Inspecta. We performed the radiographic and ultrasonic examination of  500+ welds and many other with surface techniques. These were mostly steam and condensate systems.


A piping system at TG building.

Experience, expertise, and good cooperation helped overcome project challenges.

This really exciting project has presented numerous technical and organizational challenges, as was to be expected in an undertaking of this size and complexity. Our project team addressed all issues as they arisen and in the end, we have overcome all the challenges.

To begin with, this was a very extensive project, with over 35,000 inspection hours used for non-destructive testing on our part. The inspection work had to be done on multiple plants simultaneously. We worked closely with clients’ engineering teams to plan and schedule the inspection activities so as to keep up with the overall erection progress without interfering with other construction activities. It was a very difficult task to coordinate nightly radiographic testing during the periods when the construction was going 24/7 and involved many companies from different countries. It required a very close collaboration with Andritz’s safety department and a great deal of flexibility from all parties involved. We had to re-arrange the work frequently depending on lifting equipment and scaffolds availability, shifting priorities, adverse weather conditions or local labor strikes that could paralyze the construction activities for days. Nevertheless, our project team managed all the scheduling issues confidently with a successful outcome.

100% radiographic testing of welds on massive duplex pressure vessels turned out to be one of the most challenging inspection tasks. LBNiW x-rayed over 1,5 km of heavy wall welding on a very  demanding time schedule. In order to achieve this, our experts decided to use the panoramic tube which allowed us to x-ray one full circumferential weld and its adjacent vertical sections (almost 20m of welds) at a time with a single exposure. This solution greatly improved the productivity of radiographic testing and helped to meet the inspection deadlines.

In addition, we had to comply with the very strict safety rules that were imposed by Montes del Plata. Health and safety were of paramount importance to the investor and this was an area which we gave particular focus, working closely with colleagues from Andritz and MdP. Our inspection activities were subject to intense scrutiny at times. Each workday would start with a documented safety orientation that would include risk assessment related to the particular inspection location and testing method used and cover safe work practices that remedy the identified risks. Working at heights up to 60m, or in confined spaces was our everyday reality and safety protocol had to be strictly followed and documented which was meticulously checked by site safety department.


The project execution was a great success. This showcases our capacity and competence to deliver challenging NDT programmes.

Montes del Plata project will serve as an excellent reference for high-quality inspection execution by LBNiW.