scope:

General Application

Coverage

This inspection code covers the in-service inspection, repair, alteration, and rerating activities for pressure vessels and the pressure-relieving devices protecting these vessels. This inspection code applies to all refining and chemical process vessels that have been placed in service unless specifically excluded per 1.2.2. This includes:

a. vessels constructed in accordance with an applicable construction code

b. vessels constructed without a construction code (non-code)-A vessel not fabricated to a recognized construction code and meeting no known recognized standard

c. vessels constructed and approved as jurisdictional special based upon jurisdiction acceptance of particular design, fabrication, inspection, testing, and installation

d. non-standard vessels-A vessel fabricated to a recognized construction code but has lost it's nameplate or stamping.

The ASME Code and other construction codes are written for new construction; however, most of the technical requirements for design, welding, NDE, and materials can be applied to the inspection, rerating, repair, and alteration of in-service pressure vessels. If an item cannot follow the ASME Code because of its new construction orientation, requirements for design, material, fabrication, and inspection shall conform to API 510 rather than to the ASME Code. If in-service vessels are covered by requirements in the ASME Code and API 510 or if there is a conflict between the two codes, the requirements of API 510 shall take precedence. As an example of the intent of API 510, the phrase "applicable requirements of the ASME Code" has been used in API 510 instead of the phrase "in accordance with the ASME Code."

Intent

The application of this inspection code is restricted to owner/users that employ or have access to the following technically qualified individuals and organizations:

a. An authorized inspection agency;

b. A repair organization;

c. An engineer;

d. An inspector; and,

e. Examiners.

Inspectors are to be certified as stated in this inspection code (see Appendix B). Since other codes covering specific industries and general service applications already exist (e.g. NB-23), the refining and petrochemical industry has developed this inspection code to fulfill their own specific requirements for vessels and pressure-relieving devices that fit within the restrictions listed in the scope.

Limitations

Adoption and use of this inspection code does not permit its use in conflict with any prevailing regulatory requirements. However, if the requirements of this code are more stringent than the requirements of the regulation, then the requirements of this code shall govern.

Specific Applications

Exploration and Production Vessels

All pressure vessels used for Exploration and Production (E&P) service [for example, drilling, producing, gathering, transporting, lease processing, and treating liquid petroleum, natural gas, and associated salt water (brine)] may be inspected under the alternative rules set forth in Section 9. Except for Section 6, all of the sections in this inspection code are applicable to pressure vessels in E&P service. The alternative rules in Section 9 are intended for services that may be regulated under safety, spill, emission, or transportation controls by the U.S. Coast Guard; the Office of Hazardous Materials Transportation of the U.S. Department of Transportation (DOT) and other units of DOT; the Minerals Management Service of the U.S. Department of the Interior; state and local oil and gas agencies; or any other regulatory commission.

Excluded and Optional Services

The following are excluded from the specific requirements of this inspection code:

a. Pressure vessels on movable structures covered by other jurisdictional regulations (see Appendix A (a)).

b. All classes of containers listed for exemption in the scope of the applicable construction code (see Appendix A (b)).

c. Pressure vessels that do not exceed the volumes and pressures listed in Appendix A (c).

Recognized Technical Concepts

This inspection code recognizes fitness-for-service concepts for evaluating in-service damage of pressure-containing components. API 579 provides detailed assessment procedures for specific types of damage that are referenced in this code.

This inspection code recognizes risk-based inspection (RBI) concepts for determining inspection intervals. API 580 provides guidelines for conducting a risk-based assessment.