BS 6990 covers operations relating to and involving arc welding on ferritic steel and austenitic
stainless steel land or offshore pipelines and process plant pipework which contains or has contained a process fluid and which is at least 5 mm thick. BS 6990 gives details of procedures prior to, during and after all these operations.
BS 6990 covers manual, semi-automatic and mechanized arc welding by the following processes or combination of processes:
It is essential to fully document and follow the items listed in clause 3.
Note 1: Welding on pipes of thickness below 5 mm is not covered by BS 6990 although it can be undertaken.
Note 2: The titles of the publications referred to in BS 6990 are listed on the inside back cover.
Note 3: Welding operations needing post-weld heat treatment for adequate weld quality are not within the scope of BS 6990.
Note 4: BS 6990 is not applicable to a pipeline or pipework that has been fully isolated and decontaminated or has not been commissioned.
Note 5: BS 6990 does not relate to a pipeline or pipework containing a process fluid or its residuals that will become explosively unstable upon the application of heat or will affect the pipe material by rendering it susceptible to ignition, stress corrosion cracking or embrittlement.
BS EN BS 6990 on the code of practice for welding is useful for:
Welding is a fabrication process that at first uses high heat to melt parts of metals or thermoplastics and then allows those parts to cool and join, causing fusion.
BS 6990 discusses definitions and general information that depict a user-friendly idea of the welding process. BS 6990 also provides users with welding materials and methods that contribute to the performance characteristics of steel piping systems ensuring their reliability. The guidelines in BS 6990 help you perceive the code of practice for welding that enables you to provide a superior quality product to your customers.