API Publ 938-B is a technical document for the use of 9Cr-1Mo-V (Grade 91) steel in the oil refining industry, helping professionals assess where this material may be appropriate in refinery applications. For buyers evaluating material references, the document provides a focused basis for engineering review, procurement planning, and technical alignment around a specific high-temperature steel grade. API Publ 938-B is especially relevant when teams need a dependable industry reference for selecting or reviewing material use in refining service, with attention to reliability, consistency, and documentation.

API Publ 938-B standard overview

API Publ 938-B, first issued in 2008, is an API document centered on the use of 9Cr-1Mo-V (Grade 91) steel in oil refining service. As a technical reference, it supports informed decision-making by providing recognized industry guidance around a specific alloy family rather than broad general practice. The combined standard name and official title make its purpose clear: it is intended for professionals who need a practical benchmark for material selection, review, and specification work connected to refinery equipment and related projects.

Where is API Publ 938-B used?

API Publ 938-B is commonly used in oil refining environments where Grade 91 steel may be considered for equipment, components, or project specifications involving high-temperature service. It may be consulted by engineering, procurement, inspection, maintenance, and quality teams when reviewing material suitability or documenting technical choices. In practice, it can support refinery project work, fabrication review, maintenance planning, and internal technical documentation where a consistent API reference is needed for this specific steel grade.

Practical importance of API Publ 938-B

API Publ 938-B matters because it helps teams work from a shared technical reference when evaluating a specialized material in refining service. That can improve procurement clarity, reduce ambiguity in engineering reviews, and support more consistent inspection and quality decisions. For operations and maintenance teams, it may also help align material-related planning with refinery service expectations. API Publ 938-B is useful when organizations want a controlled, industry-recognized document to support reliable use of Grade 91 steel in technical workflows.

• Grade 91 steel in refinery service
• Engineering and material reference
• Procurement and specification support
• Inspection and QA/QC alignment
• Maintenance and reliability planning
• API document for oil refining use