Oil & Gas · Petro-Chemical
Piping for Sour Service and High‑Pressure Refining
Stainless, chrome-moly, and corrosion-resistant alloy piping for refineries, upgraders, SAGD operations, and midstream facilities across Canada — supplied with full MTR traceability and vendor compliance documentation.
316 · 316L · 317L · 321 · 347 · 2205 · 6Mo · Monel · Inconel 625 P5 · P9 · P11 · P22 · P91
ASME B31.3 · ASME B31.1 NACE MR0175 / ISO 15156 · ASTM A312 · A182 · A403 Avetta #18115 · ISN #400-209938
Sector Overview
Canada's Oil & Gas Supply Chain Demands More Than Standard Stock
Upstream, midstream, and downstream oil and gas operations put piping materials under conditions that quickly expose undifferentiated stainless steel. Sour gas fields require NACE MR0175-compliant alloys. SAGD wellpads cycle between high-pressure steam and bitumen emulsion. Refinery processing units face naphthenic acid corrosion, polythionic acid stress corrosion cracking, and chloride-rich cooling water in the same facility.
Unified Alloys has been supplying the western Canadian energy sector since 1976. Our Edmonton branch stocks the pressure ratings, alloy grades, and documentation your procurement team and inspection department require — including MTRs, material certifications, and active vendor compliance accounts on the platforms your operators use to pre-qualify suppliers.
Whether you’re specifying for a refinery turnaround, a capital project on a SAGD wellpad, or ongoing MRO at a midstream compressor station, our technical sales team can match materials to service conditions and get stock moving quickly.
All stainless and CRA materials supplied with Mill Test Reports. Vendor compliance accounts active on Avetta, ISNetworld, and ComplyWorks for rapid pre-qualification.
Facilities We Supply
- SAGD wellpads and central processing facilities
- Crude distillation and coking units
- Hydrotreating and hydrocracking units
- Gas plants, amine treating, and sulphur recovery
- Midstream pipeline and compressor stations
- Petrochemical and ethylene processing facilities
Service Conditions
What You're Actually Specifying Against
Oil and gas piping failures are rarely a surprise — they're the predictable result of wrong alloy selection for a known corrosion mechanism. These are the service conditions our team specifies for most often.
Sour Service — H₂S Environments
Where H₂S partial pressure requires NACE MR0175 / ISO 15156 compliance, alloy selection is governed by hardness limits and resistance to sulphide stress cracking. Standard austenitic grades often qualify with appropriate heat treatment documentation; for more aggressive sour service, duplex and nickel alloys are specified.
Typical Grades
316L · 2205 · Alloy 825 · Inconel 625
Polythionic Acid SCC
Sensitized austenitic stainless is vulnerable to polythionic acid stress corrosion cracking during hydrotreater and coker shutdowns. Stabilized grades — 321 and 347 — resist sensitization during welding and elevated-temperature service, reducing SCC risk in hydrotreating, reforming, and delayed coking units.
Typical Grades
321 · 321H · 347 · 347H
Naphthenic Acid Corrosion
High total acid number (TAN) crude fractions corrode carbon steel aggressively in crude distillation units. Higher-alloy grades with elevated molybdenum content — 316, 317, and their stabilized variants — provide resistance in atmospheric and vacuum distillation where naphthenic acid corrosion is the primary concern.
Typical Grades
316 · 316L · 317 · 317L
High-Temperature Process Piping
Steam piping, fired heater tubes, and high-temperature process lines require creep-resistant alloys rather than austenitic stainless. Chrome-moly grades P11 and P22 cover the majority of elevated-temperature applications; P91 is specified for higher-stress, higher-temperature service such as main steam lines and superheater headers.
Typical Grades
P5 · P9 · P11 · P22 · P91
SAGD & Steam Injection
SAGD wellpad piping operates under high-pressure steam injection above 200°C and cycles through repeated pressure and temperature swings in bitumen, water, and sand emulsion service. Correct pressure class selection, ASME B31.3 compliance, and documented material traceability are baseline requirements for Alberta oil sands operations.
Typical Grades
316L · P11 · P22 · Carbon Steel
Instrumentation & Small-Bore Tubing
Control lines, instrument connections, and small-bore process connections on sour and corrosive services require the same NACE compliance as mainline piping. Instrumentation tubing in 316 SS covers most general service; Alloy 825 and 625 are specified for sour or halide-rich environments where 316 is marginal.
Typical Grades
316 SS · 2205 · Alloy 825 · Alloy 625
Materials & Grades
What We Stock for Oil & Gas
Our stocking programme covers the alloy families most commonly specified in upstream, midstream, and downstream oil and gas service. All materials supplied with Mill Test Reports. Special alloys and non-stocked grades available on request.
The primary stainless family for general process service, cooling water, and most refinery applications. 316L for general corrosion resistance; 321 and 347 for high-temperature and polythionic SCC resistance.
304 · 304L · 316 · 316L · 317L · 321 · 321H · 347 · 347H
Creep-resistant alloys for elevated-temperature and high-pressure steam service. Specified to ASTM A335 for pipe, A182 for fittings and flanges. P91 for critical service; P11 and P22 for the majority of steam piping applications.
P5 · P9 · P11 · P22 · P91
CRA options for sour service, aggressive acid environments, and high-chloride conditions where austenitic stainless is marginal. Available on request with full traceability documentation.
Duplex 2205 · 6Mo / 254SMo · Monel · Inconel 625 · Alloy 825
Ready to Order or Need Help Sizing?
Our technical sales team can help you select the right size, material, and configuration for your application.