Codes Standards and Recommended Practices. What’s the difference?

First, it’s all about standardisation

The idea of published technical documents in the integrity industry, in general, is that they should encourage standardisation of technical approach to things. This infers that multiple parties are involved, all adding their viewpoint, with some system of balloting and adjudication to reach a consensus. Many get confused at the different terms, so let’s clear it up now with Codes Standards and Recommended Practices. What’s the difference?

Standards

Standards are voluntary guidelines produced by professional Institutions or organizations which are nearly always committee-led. This (in theory) results in documents which contain requirements which are robust enough to be mandatory. The general idea is that Standards are generally not the law but do represent a proven way of doing things. Standards compliance can also form the basis of a contract between seller and purchaser if both agree to adopt it.

Codes

A document that has the status of a Code has been adopted by a legal ‘jurisdiction’ and made into law, so is legally binding. The technical scope can be the same as a standard (pipework, pressure vessels etc.) and commonly covers a raft of activities such as design, fabrication, inspection and installation making it ‘all-encompassing’. Codes contain clear sets of requirements, rather than technical discussions about the subject.

Recommended Practices (RPs)

RPs are documents containing technical information and recommendations that are not suitable to be included in a code. They indicate good engineering practices but are optional. In many cases, they are produced by Institutions and standards bodies to accompany codes. They may also be developed by commercial companies to reflect their own way of doing things. In some countries, RPs may be called PDs (Published Documents) or Guides but the principle is the same.

A typical document set

Each country has its own Codes and Standards. A good example of the document types is in the USA which has a well-developed structure involving many organizations. Legal requirements vary between states but a typical situation is;

For pressure vessels:

• ASME VIII-I Rules for Construction of Pressure Vessels is the construction standard
• API 510 Pressure Vessel Inspection Code: In-Service Inspection, Rating, Repair, and Alteration is the code
• Recommended Practices accompanying API 510 are;

API RP 572 Inspection of Pressure Vessels

API RP 579 Fitness for Service

API RP 571 Damage Mechanisms

Similar schedules of documents exist for pipework, pipelines, storage tanks, valves and other types of fixed equipment.

We cover many of these Codes, Standards and RPs in many of our API and ASME Plant Inspector training courses.

When undertaking the API ICP Certification exams, the ‘Body of Knowledge’ details the examinable subjects contained within the vast array of the available Standards and Codes which are listed in the API Examination Effectivity Sheet. You can download these from the API website, or directly below here.

• API 510 Pressure Vessel Inspector Certification – 
• API 570 Process Pipework Inspector Certification –
• API 653 Above Ground Storage Tank Inspector Certification – Body of Knowledge –