1.1 Introduction

Compliance to a code generally is mandatory, imposed by regulatory and enforcement agencies or their representatives. Also, the insurance company for the facility requires the owner to comply with the requirements of the relevant code or codes to ensure the safety of the workers and the general public. Compliance to standards normally is required by the rules of the applicable code or the purchaser’s specification.

A vast majority of these codes, standards, and specifications have their origins in the United States, because initially this is where the most oil and gas activity was based. This is not likely to change in the near future; however, in recent years, there has been an increase in the alignment with ISO, and this is likely to increase.

Despite the strength of U.S. codes, standards, and specifications, similar documents from other engineering centers should not be ignored, like British standards (UK), DIN (Germany), AFNOR (France), JIS (Japan), and others.

1.2 Definitions

A code identifies the general requirements for the design, materials, fabrication, erection, test, and inspection of process piping systems. For example, ASME B31.3—Process Piping is classified as a design code. This is the most commonly used international design code for process plants.

A standard contains more-detailed design and construction parameters and standard dimensional and tolerance requirements for individual piping components, such as various types of valves, pipe, tee, flanges, and other in-line items to complete a piping system. For example, ASME B16.5, Pipe Flanges and Flanged Fittings, is classified as a dimensional standard, but it also references ASTM material specifications.

A specification, as the word implies, gives more specific information and data on the component; and ASTM’s are considered to be material specifications, although they sometimes are ambiguously called standard specifications. ASTM A105 is the “standard specification for carbon steel forgings for piping applications.”

To conclude and combine these definitions, ASME B31.3 is a design code, with flanges designed to the ASME B16.5 standard, which are constructed to the material specification ASTM A105.

It is not uncommon for even experienced personnel to get the definitions of these three types of document mixed up, and it is important to comprehend the distinct differences.

1.3 Codes

A regulatory organization imposes mandatory compliance to a code, from the basic design through to mechanical completion and eventual hand-over of a plant to the operator. For example, ASME B31. 3, Process Piping, is the refinery code. The insurer of the plant will make this a contractual requirement to ensure safety for personnel and plant during construction, commissioning, and ongoing operation.

The codes, standards, and specifications that relate to piping systems and piping components are published by various organizations. These organizations have committees comprising representatives from industry associations, manufacturers, EPC contractors, end users/operators, government bodies, insurance companies, and other interested groups.

A committee is responsible for maintaining, updating, and revising the codes, standards, and specifications, taking into consideration all technological developments, research, experience feedback from end users, and any changes in referenced codes, standards, specifications, or regulations.

The oil and gas industry has been established for many years, and changes to industry codes are generally negligible. Periodically, revisions are published, listing amendments that have been made to the document. It is essential that engineers and designers who work regularly with the document use the latest edition.

With regard to referencing a particular edition, issue, addendum, or revision of a code or standard, the piping engineer must be aware of the national, state, provincial, and local laws and regulations governing its interpretation in addition to the commitments made by the owner and the limitations delineated in the code or standard.