PCN In-Service Inspection certification

Comparison between PCN In-Service Inspection certification and ASNT Industry Sector Qualification – Oil & Gas (ISQ-O&G) programme 

Over four years ago, PCN launched a specific certification scheme by request and with full input from the oil & gas sector starting with manual ultrasonic testing detection and monitoring of corrosion and determination of material thickness. This is a fully ISO 9712 compliant scheme available at a number of training schools and examination centres. Existing ultrasonic certificate holders may be exempt from parts of the training and examination and new entrants are eligible for the programme. To view the documentation, click here. The document references are as follows:
PCN ISI GEN Appendix B1 Guidelines ISI
PCN ISI Appendix Z1.

The below extract of the scheme information is found in document PCN ISI GEN Appendix B1 Guidelines ISI, Guidelines for detection and monitoring of corrosion and determination of material thickness using manual ultrasonic testing, issue 2, dated 22 July 2015:

These guidelines define the methods and techniques that can be utilised to carry out manual ultrasonic testing for the detection and monitoring of corrosion and the determination of material thickness within in-service vessels and piping. The examination should determine the nature and extent of all indications and ascertain the minimum material thickness within the tested areas.

1. Introduction
1.1 Piping systems and vessels can suffer from various forms of service-induced degradation, such as corrosion or erosion. These items may contain hydrocarbons, hazardous liquids and gases that may be under high pressure and/or at elevated temperature. These items may remain in service for many years; therefore, the detection of corrosion and determination of the remaining material thickness using ultrasonic techniques forms an important tool in maintaining their integrity.

1.2 For ease of use, the term ‘corrosion’ has been utilised throughout this document to represent material thickness loss regardless of the actual degradation mechanism.

1.3 Corrosion detection and determination of remaining wall thickness are often thought of as the same test but they should be considered as two separate examinations. Corrosion detection requires testing at a higher sensitivity (gain) level to allow for the detection of early stage corrosion pitting. While, in many cases, early stage corrosion may not be cause for concern, it permits the items to be identified for future, or more frequent, monitoring.

1.4 Thickness readings may be taken at predetermined locations or at the thinner areas located during corrosion detection scans.

1.5 Corrosion rates may vary from a fraction of a millimetre to several millimetres per year. A reliable inspection technique is needed to ensure corrosion rates can be accurately determined. This is of particular importance as inspection periods may be separated by many years.

1.6 Often, the aim of the thickness measurements is to determine corrosion rates rather than minimum thickness. In such cases, small systematic errors (for example, coating thickness included) in thickness measurement are acceptable provided all repeat inspections are carried out using the same test technique.

2. Modular approach for training duration
Training hours
Module 01: Product technology – Basic elements24 hours 
Module 01 is a prerequisite and must be successfully completed before moving on to modules 02, 03, 04, 05 and 06
Module 02: In-service degradation processes
16 hours
Module 03: General ultrasonic theory and basic calibration and equipment assessment
40 hours
Module 04: Practical ultrasonic training and relevant standards/procedures –Ultrasonic thickness measurement and corrosion monitoring
40 hours

ASNT Industry Sector Qualification – Oil & Gas (ISQ-O&G) programme
The purpose of the ISQ programme is to provide the oil & gas industry with NDT personnel who have demonstrated competency in practical application of a specific technique through hands-on performance demonstration qualification examinations. To view the documentation, click here.

Significant differences between the PCN and ASNT schemes
PCN In-Service Inspection certification
ASNT Industry Sector Qualification – Oil & Gas programme
• PCN is available at multiple venues• ASNT is currently available at two venues in the USA 
• PCN certification is valid for five years• ASNT supplementary qualification is valid for three years
• PCN is fully ISO 9712 compliant and a standalone certification
• ASNT is an add-on to existing certification
• PCN requires full theoretical knowledge, including specific knowledge of the oil & gas degradation processes and the limitations of thickness testing
• ASNT does not require any additional theoretical knowledge
• PCN partially meets Engineering Council registration requirements (existing experience time required)