TABLE OF CONTENTS The techniques for making line pipe and laying pipelines for transporting oil and gas were, for the most part, developed in the USA and the governing codes and standards are US or developments thereof. The code for fabricating pipelines, covering materials, welding, inspection and acceptance levels for welds is API (American Petroleum Institute) 1104. The BS version is BS 4515, which includes provision for underwater welding and for the acceptance of defects either to an arbitrary standard similar to that of API 1104 or by means of an Engineering Critical Analysis (which is discussed in Chapter 6). British Gas has its own requirements embodied in the document PSP2. In the UK there is a Pipeline Inspectorate which is part of the Department of Energy, and to gain approval from this body the line must be designed and constructed to a recognised code. UK design is covered in BS CP 2010.
In the following sections there is a brief description of methods of making line pipe and the materials used for this purpose, welding techniques and the organisation of welding operators, non-destructive testing, corrosion protection and pipe laying undersea and overland.
The API 5L requirements are shown in Table 5.1. It will be seen that these are not detailed as to chemical composition, it being the responsibility of the steel supplier or pipe manufacturer to meet the tensile minima. For the higher tensile grades the designations are 5L 42, 46 etc where 42,...
