Difference between Code, Standard, Guide & Specification

Code 

A standard adopted by government bodies (local, state and federal), a standard cited in a contractual agreement, and in force in law.

 

ASME Boiler and Pressure Vessel Code

ASME B31 Piping Code

AWS D1.1 Structural Welding Code - Steel 

BS, DIN, IS Etc.

 

 

 

Standard

A set of technical definitions and guideline developed so that items can be manufactured uniformly and provide for safety and interchangeability.

 

ASME B16 Dimensional Standard

ASTM Material Specification

SAE, ISO Etc.

 

 

 

Guide

A suggested practice, process or method that is not mandatory and may be used as a whole or in part.

 

ASME Code ; Nonmandatory Appendix

ASNT ; SNT-TC-1A Etc.

 

 

 

Specification

A document which has been developed project owner or licenser, containing detial and special requirements.

 

UOP

SHELL DEP

FOST WHEELER

ABB

SABIC Etc.