Carbon Steel Flanges · SAEP-347 Compatible
ASTM A105 and A105N carbon steel flanges to ASME B16.5 and B16.47. SAEP-347 Annex 4 compatible. Weld neck, slip-on, blind, socket weld, and threaded types. EN 10204 3.1 MTCs on every order. In-stock at our Jeddah warehouse.
Urgent supply? WhatsApp: +966 55 098 8062 — 2-hour response.
Gulf Union Ozone Trading Co. supplies carbon steel flanges from our Jeddah warehouse to Aramco contractors and EPC firms across all 18 administrative regions of Saudi Arabia. Every flange order ships with an original EN 10204 3.1 mill test certificate traceable to the producing mill. We stock flanges compatible with the SAEP-347 Annex 4 material numbers for carbon steel — see the full 59 SAEP-347 material numbers for the complete list. ISO 9001:2015 certified, CR 4030570569.
Carbon steel flanges in Saudi Arabia are forged or plate-cut piping components used to connect pipe sections, valves, pumps, and pressure vessels in process piping systems. They are the most widely used flange material type in the oil and gas, petrochemical, power, and water treatment sectors across the Kingdom due to their combination of mechanical strength, weldability, and cost efficiency.
In Saudi Aramco facilities, carbon steel flanges are governed by material specifications such as ASTM A105 (forgings for ambient and elevated temperature service), ASTM A181 (flanges for general-purpose piping), and ASTM A182 (alloy and stainless steel — separate from carbon steel but often specified alongside). The flanges are manufactured to dimensional standards — primarily ASME B16.5 for sizes NPS ½ to NPS 24, and ASME B16.47 (Series A or B) for large bore sizes NPS 26 and above.
Carbon steel's metallurgy — maximum 0.35% carbon, Manganese 0.60–1.05% — makes it suitable for service temperatures from −20°F (−29°C) to 450°F (232°C), covering the majority of process piping applications in Saudi upstream, midstream, and downstream facilities. For sour service (H₂S environments), additional requirements apply under NACE MR0175/ISO 15156.
Carbon steel flanges for Saudi Aramco projects are manufactured to three ASTM specifications. ASTM A105N, forged and normalized, is the primary grade for ASME B16.5 Class 150 through Class 2500 weld neck, blind, socket weld, and threaded flanges. ASTM A181 Grade 70 covers general-purpose slip-on and threaded flanges in lower-pressure service. ASTM A516 Grade 70 plate material is used for special large-bore blind flanges fabricated from plate rather than forgings. SAEP-347 Annex 4 contains 15 carbon steel flange material numbers, covering ASME B16.5 sizes from NPS ½ to NPS 24 across all standard pressure classes. For large-bore flanges NPS 26 through NPS 60, the dimensional standard is ASME B16.47 Series A or Series B. Every carbon steel flange supplied under SAEP-347 must carry an original EN 10204 3.1 mill test certificate from the producing mill, traceable by heat number to the item markings, with actual chemical analysis and mechanical test results confirmed. Gulf Union Ozone provides original 3.1 MTCs on every flange order.
For Saudi Aramco projects, ASTM A105 is the dominant carbon steel flange grade — it is explicitly referenced in SAEP-347 Annex 4 material numbers for forged carbon steel flanges. Understanding the difference between A105, A105N, A181, and A182 helps procurement engineers confirm the right specification before submitting an RFQ.
| Property | ASTM A105 | ASTM A105N | ASTM A181 | ASTM A182 F11 |
|---|---|---|---|---|
| Material class | Carbon steel (forged) | Carbon steel (forged, normalized) | Carbon steel (general purpose) | Alloy steel (Cr-Mo) |
| Min yield strength | 250 MPa (36 ksi) | 250 MPa (36 ksi) | 250 MPa (36 ksi) | 310 MPa (45 ksi) |
| Min tensile strength | 485 MPa (70 ksi) | 485 MPa (70 ksi) | 485 MPa (70 ksi) | 515 MPa (75 ksi) |
| Heat treatment | As-forged or annealed | Normalized | As-rolled / normalized | Normalized + tempered |
| Temp range (service) | −29°C to 538°C | −29°C to 538°C | −29°C to 538°C | −29°C to 593°C |
| Aramco SAEP-347 use | Primary grade (Annex 4) | Primary grade — specify when normalized required | General purpose — confirm Annex 4 number | Alloy — high-temp or chromium service |
Normalized vs. as-forged for Aramco projects: Aramco engineers frequently specify A105N (normalized) over standard A105 for flanges on sour or high-fatigue service lines. Normalization refines the austenitic grain, improves impact toughness, and reduces forging residual stresses. When in doubt, specify A105N — it meets all requirements of A105 and is accepted wherever A105 is called out. Gulf Union Ozone can confirm the heat treatment condition from the MTC before dispatch.
Saudi Aramco Engineering Procedure SAEP-347 defines a set of "stockable" piping material numbers — called 9COMS — that Aramco-approved contractors can procure from qualified stockists rather than directly from OEMs. The list is published in SAEP-347 Annex 4 and includes specific material numbers for carbon steel flanges in ASME B16.5 classes and sizes.
To purchase carbon steel flanges under SAEP-347, procurement engineers must:
Gulf Union Ozone stocks products compatible with the carbon steel flange material numbers in SAEP-347 Annex 4. When submitting an RFQ, include the Aramco material number from your project BOM — this ensures we quote against the exact Annex 4 specification rather than a generic equivalent. See our EPC contractor procurement guide for the complete 5-step workflow from BOM to Aramco Goods Receipt.
Long tapered hub provides reinforcement and reduces stress concentration. Standard choice for high-pressure service. ASME B16.5 class 150–2500. ASTM A105/A105N.
Slips over the pipe and is double-fillet welded. Lower cost and easier to align. Suitable for lower-pressure service. ASME B16.5 class 150–600. ASTM A105.
Solid plate used to close the end of a pipe, valve, or pressure vessel. Pressure rated to class 2500. ASME B16.5. ASTM A105/A105N.
For small-bore piping NPS ½ to 3. Pipe inserted into socket bore and fillet welded. Good for high-pressure small lines. ASME B16.5. ASTM A105.
NPT internal thread — no welding required. Limited to non-critical low-pressure lines where welding is restricted. ASME B16.5. ASTM A105.
Used with a stub end — allows flange rotation for bolt-hole alignment. Typical in lines with frequent dismantling requirements. ASME B16.5. ASTM A105.
Saudi Aramco's Goods Receipt process requires EN 10204 3.1 mill test certificates (MTCs) for all SAEP-347 materials. A 3.1 certificate is validated and signed by the manufacturer's own qualified 3.1 inspection representative — not a third party, and not the stockist. Gulf Union Ozone forwards original 3.1 MTCs from the producing mill with every carbon steel flange order.
Aramco EPC projects involve multiple flange material types across different service lines. The table below provides a quick reference for the most common flange material selection decisions in Saudi industrial applications.
| Service Condition | Recommended Grade | Standard |
|---|---|---|
| Standard hydrocarbons, utilities, steam (non-sour) | Carbon steel A105/A105N | ASME B16.5 |
| Sour service — H₂S environments (NACE MR0175) | A105N (hardness ≤22 HRC) or low alloy with HIC test | NACE MR0175/ISO 15156 |
| High temperature above 260°C, creep-resistant service | Alloy steel A182 F11 (Cr-Mo) or F22 | ASME B16.5 |
| Chloride-containing environments, seawater cooling | Stainless steel A182 F316/F316L | ASME B16.5 |
| Cryogenic service (LNG/LPG) below −50°C | Stainless steel A182 F304L or nickel alloy | ASME B31.3 |
| General Aramco process piping — SAEP-347 9COM | Carbon steel A105/A105N (dominant Annex 4 grade) | SAEP-347 Annex 4 |
Gulf Union Ozone stocks carbon steel, stainless steel (304/316/316L), and selected alloy steel flanges. For full flange range including duplex stainless and high-nickel alloys, see our complete flanges product page.
Gulf Union Ozone's carbon steel flanges are held in stock at our warehouse in Jeddah, Western Region. In-stock items dispatch same-day or next-business-day for orders confirmed before 14:00 AST. Documentation (EN 10204 3.1 MTC + Certificate of Conformance) is prepared in parallel with dispatch preparation — no documentation delays.
| Destination | Transit Time from Jeddah |
|---|---|
| Jeddah (local), Makkah, Madinah, Yanbu | Same day / next day |
| Riyadh, Al Jubail, Dammam, Al Khobar | 24–48 hours |
| Tabuk, Hail, Buraidah (Qassim) | 48–72 hours |
| Abha, Khamis Mushait, Jizan, Najran | 48–96 hours |
| Umluj, NEOM corridor, Tabuk coast (Red Sea Projects) | Same day from Umluj branch (select items) |
Transit times are from order confirmation to arrival at delivery address. Same-day dispatch applies to in-stock items ordered before 14:00 AST. Emergency courier dispatch available for urgent plant shutdowns — WhatsApp +966 55 098 8062. For Eastern Province projects (Dammam, Jubail, Al Khobar), see our Jubail delivery page.
ASTM A105N is the normalized condition of A105 — same specification, different heat treatment. Normalization refines the grain structure, improves impact toughness, and reduces forging residual stresses. Aramco engineers frequently specify A105N for sour or high-fatigue service lines. A105N is accepted wherever A105 is called out. Gulf Union Ozone can confirm heat treatment from the MTC before dispatch.
Yes — original EN 10204 3.1 MTCs from the producing mill are included with every order. The certificate shows actual (not "per spec") chemical analysis and mechanical test values, heat number, and the 3.1 inspector's signed credentials. We do not supply photocopies. See our full EN 10204 3.1 guide for Aramco projects.
Submit an RFQ via contact form, email info@gulfunionozone.com, or WhatsApp +966 55 098 8062. Specify: flange type, ASME class, NPS, material grade, quantity, delivery location, and the Aramco material number from your project BOM if available. We respond within 4 business hours.
We stock ASME B16.5 flanges from NPS ½ through NPS 24 in classes 150#, 300#, 600#, and 900#. Types include weld neck, slip-on, blind, socket weld, and threaded. For large bore NPS 26+ (ASME B16.47 Series A/B), availability is confirmed at quotation stage. Contact us with your size and class for a current stock check.
Weld-neck flanges for high-pressure and high-temperature service at Saudi Aramco refineries and gas plants are the most common SAEP-347 flange type — their bore matches the pipe bore exactly (no step) eliminating turbulence and providing superior fatigue resistance in cyclic thermal service. Gulf Union Ozone supplies ASME B16.5 weld-neck flanges in Class 150 through Class 2500 from ASTM A105 carbon steel forging with RT (radiography test) per ASME VIII for Class 600 and above as required by SAEP-347 Annex 4. Long-weld-neck (LWN) flanges for nozzle connections on Saudi Aramco pressure vessels. Blind flanges in Class 150 through 2500 for pressure testing and future connection isolation. Spectacle blinds and slip blinds for Saudi Aramco isolation procedures during plant shutdown and maintenance. SAEP-347 Annex 4 material number is cross-referenced on every flange quotation for Aramco MR documentation.
For an accurate quotation, specify: flange type (WN / SO / BL / SW / TH), ASME class (150# to 2500#) or PN rating, nominal pipe size (NPS / DN), material grade (ASTM A105 or A105N), quantity, and delivery location. If you have an Aramco material number (6000XXXXXX format) from your project BOM, include it — this ensures we quote the correct Annex 4 specification. We respond within 4 business hours.
Gulf Union Ozone carbon steel flange supply delivers across Saudi Arabia from the Jeddah warehouse: ASME B16.5 flanges in Class 150, 300, 600, 900, 1500, and 2500 from ½" to 24" NB are held in bonded stock; Jubail and Dammam 48–72 hours; Al Khobar 72 hours; Riyadh 72–96 hours; Jeddah same-day. Emergency flange supply for Saudi Aramco turnarounds — including large-diameter Class 600 weld-neck flanges not normally stocked — is sourced on express airfreight from European and Asian manufacturers with 5–7 day lead time. EN 10204 3.1 mill test certificates from approved ASTM A105 forge masters are supplied with every delivery to Saudi Aramco facilities. ASME B16.47 large-diameter flanges (above 24" NB) are sourced on project-order basis with 6–10 weeks lead time.