Gulf Union Ozone sources ASME B16.47 large bore flanges to order for Saudi Arabia projects. Series A (based on MSS SP-44) and Series B (based on API 605). Blind, weld neck, and slip-on ring flange types in carbon steel, alloy steel, and stainless steel. EN 10204 3.1 mill test certificates supplied. Lead time 6–14 weeks depending on size and material. Submit RFQ with size, series, class, material, and quantity.

ASME B16.47 (Large Diameter Steel Flanges: NPS 26 Through NPS 60) is the ASME standard governing steel flanges for pipe sizes above the NPS 24 limit of ASME B16.5. It covers two dimensional series — Series A (formerly MSS SP-44) and Series B (formerly API 605) — for pressure classes 75 through 900. Large diameter flanges under B16.47 are used in transmission pipelines, mainline process headers, large vessel nozzles, offshore platform piping, and any application where the process line diameter exceeds NPS 24.
In Saudi Arabia, ASME B16.47 large diameter flanges appear on Saudi Aramco crude oil trunk lines, natural gas transmission systems, refinery and NGL main headers, SABIC petrochemical plant large-bore sections, and major water injection pipeline flanges. The SAEP-347 piping material standard does not explicitly enumerate B16.47 flange material numbers in the same way as B16.5 flanges, so project material engineers must confirm the appropriate material class and heat treatment requirement for each application.
Series A and Series B flanges are NOT interchangeable. They share the same pressure class names and the same ASME standard but have different outside diameters, bolt circle diameters, and bolt hole counts. A Series A flange bolted to a Series B counterpart will not align. Always verify the series required by your project piping specification before ordering.
| Feature | Series A (MSS SP-44) | Series B (API 605) |
|---|---|---|
| Origin standard | MSS SP-44 (Manufacturers Standardization Society) | API 605 (now withdrawn, dimensions preserved) |
| Typical use sector | Refinery / petrochemical / process plant | Transmission pipeline / offshore |
| Outside diameter | Larger OD for same NPS/class | Smaller OD — more compact |
| Bolt circle diameter | Different from Series B | Different from Series A |
| Pressure classes | 150, 300, 400, 600, 900 | 75, 150, 300, 400, 600, 900 |
| Class 75 available? | No | Yes |
| Interchangeable with each other? | NO — completely different bolt circle and OD. Do not mix. | |
| Material | Spec | Temperature Range | Typical Application | Lead Time |
|---|---|---|---|---|
| ASTM A105N (Normalised CS) | ASME B16.47 A or B | −29°C to 538°C | General carbon steel, low-temp service | 8–12 wks |
| ASTM A516 Gr.70 (Plate-derived) | ASME B16.47 A or B | −50°C to 343°C | Vessel nozzle flanges, low-temperature | 8–12 wks |
| ASTM A182 F11 (1¼Cr½Mo) | ASME B16.47 A or B | −29°C to 593°C | High-temperature process, refinery heaters | 10–14 wks |
| ASTM A182 F22 (2¼Cr1Mo) | ASME B16.47 A or B | −29°C to 649°C | HP steam, high-temp hydrocracking | 10–14 wks |
| ASTM A182 F304L | ASME B16.47 A or B | −196°C to 399°C | Cryogenic, corrosive service | 10–14 wks |
| ASTM A182 F316L | ASME B16.47 A or B | −196°C to 399°C | Seawater, chloride-bearing service | 10–14 wks |
Lead times are indicative from mill order placement. Actual lead time depends on foundry loading, NPS size, and heat treatment requirements. Confirm with Gulf Union Ozone at RFQ stage.
| Criterion | ASME B16.5 | ASME B16.47 |
|---|---|---|
| Size range | NPS ½" to NPS 24" | NPS 26" to NPS 60" |
| Pressure classes | 150, 300, 600, 900, 1500, 2500 | 75, 150, 300, 400, 600, 900 (Series B); 150, 300, 400, 600, 900 (Series A) |
| Maximum pressure class | 2500 | 900 (limited by practical flange size) |
| Ex-stock availability | Yes — NPS ½ to 24" in A105 | No — all sizes fabricated/sourced to order |
| Gulf Union Ozone stock | Ex-stock (blind, WN, SO in A105) | Sourced to order — RFQ required |
| Saudi Aramco use | Process piping (SAES-L-108) | Trunk lines, large-bore headers, vessel nozzles NPS 26+ |
Carbon steel sizes NPS 26–36 in Class 150 and 300 typically ship in 6–8 weeks. Larger sizes (NPS 42–60), higher classes (Class 600–900), and alloy/stainless grades are 10–14 weeks. Plan B16.47 flanges at the earliest stage of project procurement — they are not standard stock items anywhere in Saudi Arabia.
Series A is derived from MSS SP-44 and is commonly used in refinery and petrochemical piping. Series B is derived from the now-withdrawn API 605 standard and is used in pipeline and offshore applications. The two series are not interchangeable — they have different outside diameters, bolt circle diameters, and bolt hole counts for the same NPS and pressure class. A mismatch cannot be corrected in the field. Always confirm the required series from your project piping specification or piping material class (PMC) document before ordering.
For ASTM A105 carbon steel flanges in sizes and wall thicknesses above certain limits, ASME B16.47 requires normalising (N) heat treatment. A105N denotes a normalised forging — this is common for larger bore flanges where the through-wall thickness is such that the as-forged properties may not meet impact or toughness requirements. For Saudi Aramco projects, the project piping specification or SAES-H-001 may impose additional heat treatment requirements beyond the base standard. Always confirm the heat treatment requirement with your material engineer before ordering.
Yes. Gulf Union Ozone sources ASME B16.47 Series A and Series B flanges to order from qualified mills supplying EN 10204 3.1 mill test certificates, dimensional inspection reports, and ISO 9001:2015 compliant quality documentation packages. As a Saudi LLC registered under CR 4030570569 with Jeddah warehouse operations, all commercial documentation complies with Saudi VAT and SAEP-347 project commercial requirements. Submit your RFQ with the full specification (series, NPS, class, material, facing, quantity, delivery date) for a lead time and price indication.
Gulf Union Ozone sources ASME B16.47 Series A and Series B flanges to order from Jeddah. Include series, NPS, pressure class, flange type, material grade, facing, and quantity in your RFQ. EN 10204 3.1 MTCs and full quality documentation supplied with every order. Lead time and price indication provided within 2 business days of RFQ receipt.
Gulf Union Ozone Trading Co. supplies ASME B16.47 Large Diameter Flanges to industrial customers across Saudi Arabia with delivery from our Jeddah warehouse — all products ship with original Mill Test Certificates and Certificates of Conformance.
ASME B16.47 Large Diameter Flanges from Gulf Union Ozone serves Saudi Aramco SAEP-347 projects, SABIC, SADARA, SEC utilities, NEOM mega-projects, and industrial facilities across the Kingdom — our inventory covers the most common material grades and pressure ratings.
Gulf Union Ozone stocks a wide range of ASME B16.47 Large Diameter Flanges including various grades, sizes, and pressure classes — contact us on WhatsApp for immediate availability confirmation and a quotation with full MTC documentation.
For urgent ASME B16.47 Large Diameter Flanges procurement in Saudi Arabia, WhatsApp +966 55 098 8062 — our procurement team confirms stock availability within the hour and provides competitive quotations with full compliance documentation for Aramco, SABIC, SEC, and government projects.