FOREWORD
THIS SECOND, completely-revised, edition of Pipeline Pigging Technology is essentially a compilation of selected papers presented at the conferences organized by Pipes & Pipelines International and Pipe Line Industry
in the UK and the USA between 1988 and 1991. The book is thus a successor
to the first edition, published in 1987, and brings readers up-to-date with the
rapidly-developing technology of pipeline pigging.
Although the international pigging industry has unquestionably made
major advances in its scope and expertise over the intervening years, it is
nevertheless apparent that the comment made in the earlier book - that there
is a general lack of knowledge about the use of pipeline pigs of all kinds - is
still relevant today. Not only have the conferences at which these papers were
presented produced questions such as 'How do I interpret the results of this
intelligent pigging inspection?', but they also continue to produce the most
basic of pigging questions such as 'Should I use discs or cups?' or 'Will foam
pigs or rigid pigs work the best in this application?'.
It cannot be claimed that this book will provide readers with the answers
to all their questions; indeed, many such answers remain in the experimental
field of 'try it and see'. Nevertheless, we have gathered together in this edition
a collection of 33 papers which give a comprehensive overview of the current
situation, written by respected authors, from whom further information can
undoubtedly be readily obtained by seriously-interested readers and organizations.
It is significant to note that, in early October, 1991, the first-ever major
research project into the performance of 'conventional' pigs was entering its
second phase. At the same time, the Pigging Products and Services Association
was developing into a healthy organization with increasing membership,
while the world's first long-distance gas pipeline designed with a total
commitment to intelligent pigging was being constructed in the North Sea.
These three discrete activities show that the hydrocarbons pipeline industry
is paying increasing interest to pigging, which is seen, more-and-more widely,
as an important aspect of future pipeline operations.
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Readers will find in this book papers that cover subjects more diverse than
simply the practicalities of pigging. I make no apology for this, as the basic
requirements for pigging have now to be seen in a wider context, the
boundaries of which are increasingly being set by legislation. Concepts such
as 'fitness-for-purpose' and 'integrity management', the practical development of which will allow an operator to manage his pipeline with greater
precision and safety, will nevertheless be based on data obtained from
successful pigging operations.
On page xii will be found a list of the contributors, together with
references to the conferences at which their papers were originally presented. I am greatly indebted to all these authors, both for their willingness
to participate in the conferences, and for their agreement to allow their
papers to be published in this book.
It should be explained that, although edited as far as possible into a uniform
appearance, the papers appear here in the same form as that in which they
were originally presented. Any errors are, of course, my own.
John Tiratsoo, October, 1991
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