What is the Difference between Code, Standard and Specification?

The difference between Code, Standard and Specification is very important.

What is Standard?  

Follow TWI:


Below maybe easy understand:

Standard can define as a set of technical definitions and guidelines – or simply a “how to” instructions for designers and manufacturers. It gives all the necessary requirements for the product, service, and operation.

A designer will use the standard to design the product, and a manufacturer will use the standard for the manufacturing of the product.

Standard serves as a common language for defining quality and establishing safety criteria for the product. ASTM, API, ISO are some examples of the standard. ASTM has more than 12000 standards they cover all most everything.

What is Code?

When governmental bodies adopt the standard and become legally enforceable, or when it has been incorporated into a business contract, the standard will become a code.

ASME Codes are legally enforceable in many US state. Whereas, in the other part of the world they are not legally enforceable but such countries have their own similar codes.

Please note that requirements mentioned in the code will only be mandatory requirements if

  • The Code is adopted as law by a regulatory body
  • It is a part of the business contract

Otherwise, Code will serve as generally accepted guidelines for design, fabrication, construction, and installation,

However, all most all process facility follows various American code and Standard in addition to their national standard.

  • Examples of the codes are ASME Boiler and Pressure Vessel Code, BS, DIN, etc.

What is Specification?


Specifications provide specific/additional requirements for the materials, components or services that are beyond the code or standard requirements

  • For Example, if you want A106 Gr B pipe with Maximum carbon of 0.23% against standard requirements of 0.3% Max, you have to specify your requirement in your specification or Purchase Order.
  • Specification is generated by private companies to address additional requirements applicable to a specific product or application.

Difference Between Code, Standard and Specification in Piping.

Documents for reference:

+ Learn about what is the difference between Piping and pipeline.


+ TWI training

Thank a lot!

One thought on “What is the Difference between Code, Standard and Specification?

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s