Page 124 - Quick Guide to Welding and Weld Inspection by S.E. Hughes, Clifford Matthews

Chapter 8

Codes, Standards and Documentation

Codes and standards
Reference is often made in books (including this one) and
quality documentation to ‘compliance with the relevant
specification, code or standard’ but a common question is
‘what is the difference (if any) between them?’ Unfortunately
there is no universally agreed definition of what specifically
constitutes a code or standard but the following loose
definitions are acceptable.
A code is generally:
. A set of rules that must be followed when providing a
specific product or service.
A standard may:
. refer to standard procedures such as examinations and
tests of materials and personnel;
. be a specification for a material or manufactured product
and may either be written by companies for internal use or
by national and international bodies for public use;
. be a document referred to by a code and contain optional
or mandatory manufacturing, testing or measurement
data. For example, a pressure vessel will be manufactured
to a code using materials meeting the quality levels
contained in a standard. In reality it is often not that
simple because many standards are actually codes in all
but name.
A code of practice is normally legally binding and contains all
the rules required to design, build and test a specific product.
Compliance with the ASME Boiler and Pressure Vessel
(BPV) code, for example, is a legal requirement in most states

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Woodhead Publishing Ltd – A Quick Guide to Welding and Weld Inspection
Data Standards Ltd, Frome, Somerset – 17/9/200908QG Welding chap8.3d Page 108 of 124