ASME B31.3 is the internationally recognised code for process piping - the pipework that carries chemicals, gases, steam and process fluids in refineries, petrochemical plants, and industrial facilities. On virtually every serious industrial project in Qatar, from Ras Laffan to Mesaieed, compliance with ASME B31.3 is a contractual requirement, not an optional extra.
What ASME B31.3 actually covers
The code sets the rules for the design, materials, fabrication, examination, inspection and testing of process piping. In practice that means it governs how pipe wall thickness is calculated for pressure and temperature, which materials are acceptable for a given service, how welds must be made and qualified, and how the finished system is inspected and pressure-tested before it is handed over.
The key requirements in plain terms
Design: pipe and components are sized for the maximum design pressure and temperature, with corrosion allowance. Materials: every material must be traceable to a Mill Test Certificate (EN 10204 3.1) and verified - we PMI-check alloys on site. Welding: welds follow qualified Welding Procedure Specifications (WPS) with supporting Procedure Qualification Records (PQR), and welders are qualified to ASME Section IX (typically 6G). Examination: welds are inspected visually and by NDT - radiography (RT), dye penetrant (PT), magnetic particle (MT) or ultrasonic (UT) - to the percentage the code and client require. Testing: completed systems are hydrostatically or pneumatically tested, usually to 1.5x design pressure.
ASME B31.3 vs B31.1
The two are often confused. B31.3 (Process Piping) applies to chemical, petrochemical and process plants; B31.1 (Power Piping) applies to power-station boiler and steam systems. Many Qatar industrial sites need both, so we qualify our procedures and welders across the relevant codes.
How it applies in Qatar
On Qatari projects, ASME B31.3 sits alongside Qatar Construction Specifications (QCS 2014) and client or QatarEnergy project specifications. As a mechanical subcontractor we deliver code-compliant piping with the full paper trail - Inspection and Test Plans (ITPs), WPS/PQR, NDT reports and test records - so main contractors and inspectors can sign off smoothly.
Planning an industrial package? See our industrial & petrochemical piping service, or our contractor pages for Ras Laffan and Mesaieed.
Need ASME B31.3-Compliant Piping?
Our ASME-certified crews deliver code-compliant process piping with full documentation across Qatar. Request a technical review.
ASME B31.3 FAQs
Common questions on process piping code compliance in Qatar.
Is ASME B31.3 mandatory for piping in Qatar?
For process, petrochemical and industrial piping it is effectively mandatory - it is written into client and QatarEnergy specifications and QCS 2014 references it. Compliance is required for inspection sign-off and handover.
What is the difference between ASME B31.3 and B31.1?
B31.3 covers process piping in chemical and petrochemical plants; B31.1 covers power piping such as boiler and steam systems in power stations. Many Qatar sites require both.
How do you prove ASME B31.3 compliance?
Through qualified WPS/PQR, ASME Section IX-qualified welders, EN 10204 3.1 material certificates, PMI verification, NDT reports (RT/PT/MT/UT) and pressure-test records, all compiled in an ITP documentation package.
Are your welders qualified for ASME B31.3 work?
Yes - our welders hold ASME Section IX qualifications, typically in the 6G position, working to approved procedures for each project.