Anti-HIC Pipe Fittings: What Gulf EPC Contractors Need to Know

Hydrogen Induced Cracking (HIC) remains one of the primary failure modes in Gulf sour gas piping. This guide explains what Anti-HIC fittings are, why ADNOC and Saudi Aramco mandate them, and what documentation to request from your supplier.

What is Hydrogen Induced Cracking (HIC)?

Hydrogen Induced Cracking occurs when atomic hydrogen — produced by corrosion in the presence of hydrogen sulfide (H₂S) — diffuses into steel and recombines at internal defects, generating internal pressure that creates planar cracks parallel to the steel surface.

In the Gulf's sour gas fields, where H₂S concentrations can exceed 10%, HIC is not theoretical — it is a documented, service-proven failure mechanism that has caused catastrophic pipeline failures. ADNOC, Saudi Aramco, and Kuwait Petroleum Corporation all mandate HIC-resistant materials for wet sour service.

How Anti-HIC Fittings Are Made

Anti-HIC pipe fittings are manufactured from specially controlled steel with:

• ✦Low sulfur content (≤0.003% S) — sulfide inclusions are the primary HIC nucleation sites
• ✦Controlled carbon equivalent — limits susceptibility to hydrogen embrittlement
• ✦Clean steel melting practices — vacuum degassing, ladle refining to minimize inclusions
• ✦Calcium treatment — shapes remaining sulfide inclusions to reduce HIC susceptibility
• ✦Controlled rolling — limits centerline segregation in the final product

The finished fittings are tested per NACE TM0284 (HIC resistance) and NACE TM0177 (SSC resistance) at accredited third-party laboratories. Test results — including CLR, CTR, and CSR values — form part of the material test certificate (MTC) package.

ADNOC Requirements

• ✦H₂S partial pressure exceeds 0.0003 MPa, OR
• ✦pH is below 6.5 in aqueous environments

ADNOC Vendor Code 20013477 (Kaiyuan Pipeline) covers Anti-HIC seamless fittings, induction bends, and flanges that have been supplied directly to ADNOC gas processing facilities since 2020.

Documentation Checklist for Anti-HIC Fittings

When procuring Anti-HIC fittings, require your supplier to provide:

1. MTC EN 10204 Type 3.1 — heat/lot-specific chemical and mechanical test results 2. HIC test certificate — per NACE TM0284, including CLR, CTR, CSR values 3. SSC test certificate — per NACE TM0177 Method A or C (as specified) 4. Heat treatment record — normalizing or quench-and-temper parameters 5. Dimensional inspection report — per ASME B16.9 6. NDE reports — UT, MT or PT as specified 7. Certificate of Conformity — referencing applicable project specification

Kaiyuan Pipeline: Gulf's Preferred Anti-HIC Supplier

Kaiyuan Pipeline (Henan Xinkaiyuan Petrochemical Pipeline Co., Ltd.) has been manufacturing Anti-HIC pipe fittings since the 1990s. With API Q1 registration, ASME PP certification, and ADNOC Vendor Code 20013477, they represent the standard for Gulf Anti-HIC supply.

Orient Bridge Trading is the exclusive Gulf representative. Contact us for specifications, pricing, and documentation samples.