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Non-Destructive Testing and Inspection Issues in Industrial Plants

Non-destructive testing (NDT) and Inspection of industrial equipment is important in oilfield production, petroleum refining, petrochemicals and power generation sectors. The NDT techniques include both conventional and advanced techniques. NDT is a noninvasive technique for determining the integrity of a material component or structure.  It allows inspection without interfering with a product's final use that provides an excellent balance between quality control and cost-effectiveness. The main goal of NDT is to detect material defects such as corrosion/cracks, to predict corrosion rates or to assess equipment mechanical integrity, to calculate corrosion risk and to assess remnant life.

The NDT user industry has been realizing quality, safety benefits and cost avoidance, especially by detecting corrosion before it is too late. The NDT user industry is bound by stringent government regulations, new industry specifications, supply of quality products, cost saving and  ever growing competitions, which eventually force them to extend plant and equipment run times, to stretch maintenance intervals, to extend inspection intervals for critical equipment and to reduce operating cost.

Having mentioned the above situation, it is essential to highlight the issues, which NDT industry has been facing in Pakistan:

Growing Demand of Trained NDT Personnel: Number of NDT user companies have introduced qualification and/or certification programs to promote the use of competent NDT personnel. The training of NDT personnel to meet the rising demand is a serious concern.

Non-Availability of a Large Number of NDT Personnel for a Short Period: Traditionally during turnarounds and shutdowns large number of NDT personnel are required by NDT user companies to be on site for a short period of time to complete the inspection scopes. Whereas it is difficult to make available NDT personnel to perform NDT work during these plant outages.

Relocation of NDT Personnel: The NDT personnel have been continuously relocated in the Middle East and other countries at lucrative terms. In this situation, Pakistani NDT market has been facing significant shortage of NDT personnel.

Increasing Cost of NDT Services: The cost to NDT users greatly exceeds this since much inspection is highly labor intensive and extensive preparation for inspection is often required. A continuing drive to increase the speed of inspection, to reduce the preparation required and, if possible, to inspect without the need to shutdown operation.

Rising Demand of Efficient NDT Methods: Time stretched maintenance intervals and extended run times, have made quantitative detection of cracks and corrosion in plant and equipment highly desirable. This requires efficient NDT methods that do not require long down times for inspections, and are fast and reliable for production inspection. Supply of efficient NDT methods are difficult to manage all the time.

Handful Local NDT Equipment Calibration Agencies:  NDT equipment requires periodic calibration for their sustained usage.  There are only handful agencies in Pakistan that provide calibration services for these equipment.  NDT equipment are generally sent to overseas for calibration purpose, which takes considerable time and absence of the equipment from duty.  Moreover, for the calibration of advanced NDT equipment, not a single agency offers this service in Pakistan.

Absence of Plant Inspection & Maintenance History: Equipment Inspection/maintenance histories or records plays significant role in evaluation of inspection findings particularly for old equipment.  In majority of cases, these records do not exist with NDT user companies.

Non-Existence of Isometric Drawings:  Likewise, existence of Isometric drawings for piping and vessels are vital for inspection planning, data gathering and data recording. Generally, these drawings do not exist in the companies.

Passive Correlation between Corrosion Monitoring & NDT Results: Efficient corrosion monitoring is a must activity for oil and gas production fields as a one of the Intrusive inspection techniques (On-line/Offline). The results obtained through the corrosion monitoring provide directly information about internal corrosion rates and damage mechanisms.  It is noticed that NDT and Inspection personnel rarely has active correlation with each other on sustained basis.   

High Landing Cost of Advanced NDT Equipment: All types of advance NDT equipment are imported from international market. Decreasing value of Pakistani rupees against international trade currencies has been causing sharp increasing cost of these advanced NDT equipment. 

Need of ISO 17020 Accredited NDT Service Providers: ISO17020 standard specifies general criteria for the competence of impartial bodies performing inspection bodies. In Pakistan, there is a need of ISO 17020 accreditation of NDT service providing bodies.

Training of NDT Personnel Severely Affected: Most of the large users of NDT  have initiated outsourcing of NDT services. The result of this outsourcing of NDT services is that training process of NDT personnel has been severely affected, as these companies no longer train in-house personnel in the necessary skills.

High Training Fees: High tuition fees are charged by NDT training institutions in Pakistan, which is not affordable by the individuals who are interested in getting training at their own.  

Low Regular-Employment-Opportunities for NDT Personnel: Most NDT user companies only employ a small number of staff on regular-employment-basis to manage their NDT requirements, and invite NDT service providers to perform NDT services only when plants are taken off line during plant outages.

Effective deployment of appropriate NDT personnel and implementation of efficient inspection methodologies to the NDT user industry are undoubtedly indispensable in ensuring the reliability, safe and economic use of these facilities. If NDT industry issues are not tackled head-on, the realization of cost saving, quality and safety benefits may not be achieved.

Yousuf Memon
Plant & Equipment Integrity Professional, has been working for national & international upstream, midstream and downstream for several years.  At present, he is CEO of Pakistan based NDT & Plant inspection company, Reliance Swift Veritas (RSV), Karachi.





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