Recommended practice for the rapid inspection of small bore connectors using radiography

This document covers recommended practice for the radiographic inspection of corrosion in small bore piping and in the small bore connections to larger diameter main pipes. Inspection of this type of component is not covered by any internationally recognised standards or procedures, and there is therefore a need for guidance on recommended practice. Recommendations are given concerning techniques for detection of corrosion within different regions of small bore connectors and their junction with main pipes. A distinction is drawn between corrosion in the form of relatively uniform loss of wall and isolated corrosion pits. Recommendations are given regarding the key technical aspects of in-situ radiographic inspection techniques including radiation sources, film types, computed radiography systems, positioning of the source and film (or filmless plate) and methods for reduction in exposure time. This report and the work it describes were funded in part by the Health and Safety Executive (HSE). Its contents, including any opinions and/or conclusions expressed, are those of the authors alone and do not necessarily reflect HSE policy. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means (electronic, mechanical, photocopying, recording or otherwise) without the prior written permission of the copyright owner. This document covers recommended practice for the radiographic inspection of corrosion in small bore piping and in the small bore connections to larger diameter main pipes. Inspection of this type of component is not covered by any internationally recognised standards or procedures, and there is therefore a need for guidance on recommended practice. The information obtained from the HOIS2000 radiographic evaluation trials is used as the basis for this recommended practice document. Appropriate standards are also referenced, including ISO 2919: 1999 and ISO 3999-1:2000, which cover radiation protection aspects of gamma ray sources and containers. BS EN 1435 which is a standard for radiographic examination of welds is also referenced. Recommendations are given concerning techniques for detection of corrosion within different regions of small bore connectors and their junction with main pipes. A distinction is drawn between corrosion in the form of relatively uniform loss of wall and isolated corrosion pits. Recommendations are given regarding the key technical aspects of in-situ radiographic inspection techniques including radiation sources, film types, computed radiography systems, positioning of the source and film (or filmless plate) and methods for reduction in exposure time.