Euro Petroleum Consultants (EPC) have been appointed as technical consultants by Orsk Refinery, a 6.6 million tpy independent refinery located in the Volga Federal District of Russia, near the border with Kazakhstan. The refinery is now at an advanced stage in its development programme and one of the core production facilities under construction is a VGO Hydrocracking Complex. EPC's experts provide support to the refinery in various fields, including control of welding quality for high-pressure pipelines. Below please find an article regarding the cooperation between EPC and Orsk Refinery which was published in the refinery's internal newsletter.
|EPC specialists inspect internal side of the welded joint|
By Anastasiya Polyakova
The Hydrocracking Complex at Orsk Refinery includes kilometers of high-pressure (HP) pipelines. The integrity and quality of the pipelines’ connections will determine the operation of the overall Complex. The pipelines’ welding is being monitored by Euro Petroleum Consultants using a special technology.
Euro Petroleum Consultants (ЕРС) are the technical consultants for PJSC “Orsknefteorgsintez”. They provide assistance in monitoring implementation progress of the main projects within the Orsk Refinery development programme. One of the main types of work at the Hydrocracking Complex is the quality inspection of welded joints at HP pipelines.
As Igor Sosnovets, EPC Project Manager, puts it: “These pipelines are crucial as they will transport high temperature products under high pressure. Moreover, the pipelines of the Hydrocracking Complex are manufactured using a special technology, and welded joints are performed in accordance with ASME (American Society of Mechanical Engineers) standards. That is why we invited certified foreign partners – Gerard Nobin, Peter Frost and Ashton Gaskell – to inspect the quality of the welded joints. Russia simply lacks specialists of such qualification. This should not be interpreted as EPC mistrusting local specialists, but rather as additional supervision by higher qualified specialists experienced in implementing such large-scale projects worldwide.”
There are many methods to monitor welded joints, and they all differ in operating principle, efficiency and equipment. For extra precision EPC specialists employ several methods at a time. Each check of the welded joint starts with a visual inspection, this allows detection not only of external defects, but also some internal ones, for example, difference in height and width along the joint, cracks, irregular weld shape, etc. Additional lighting, metering equipment, mirrors and camera are also used during inspection. Cameras enable specialists to zoom in on an image for display on a special screen, thus ensuring thorough inspection of the pipeline’s internal surface.
However only some of the possible defects can be identified by means of visual inspection. Some hidden defects are deep inside the weld, others are so small that they can only be detected with the help of special instruments. Therefore, at Orsk Refinery the inspectors apply one of the most efficient testing methods – radiographic testing (RT). RT’s operating principle is similar to that of taking medical X-ray images. Subjected to X-rays, any inclusions, cracks and the smallest of defects affect the amount of radiation received by radiographic film. The advantages of RT are in maximising accuracy, prompt detection of various discrepancies – not just the mere existence but also the location of such discrepancies even when they are in the least accessible areas.
Seventy-four specially trained welders are currently working at HP pipelines, each has his own signature line, work experience and weld style, therefore, each welded joint must undergo inspection. Moreover, one joint 400 mm in diameter is welded by a pair of welders for around 20 hours, with the number of welded joints totaling 4921. This figure only includes the joints that are part of HP loop. It is the clearly defined schedule that helps the EPC specialists to cope with such a vast scope of work.
In the words of Igor Sosnovets: “Every morning JSC “Promfinstroy” employees file requests for visual inspection of the welded joints. They bring X-ray images of pipes welded during the previous day and night shift. We use this as the basis for our planning, while one specialist interprets the images the other two go to the construction site to visually inspect internal and external sides of the welded joint. After the work day is over we conduct a meeting to summarise the results. In addition, for better monitoring of the process, we enter daily the work progress report into the computer making it easier to control the process in general.
The work of EPC specialists directly depends on the welders, all inspections are currently performed according to the schedule and “Promfinstroy” employees take note of every recommendation so as to avoid future mistakes and faults.”
To sum up, Igor Sosnovets says: “The welded joints inspectors should follow the job from the initial stage all the way through to its completion. In other words, the one who starts the job should be there to finish it. That is why we will stay at the Refinery until all the welding work on HP pipelines is completed.”
Source: Orsk Refinery Newspaper (Aug 2017, p4)
Author: Anastasiya Polyakova