Certified steel plate & flat welding flanges engineered for low-temperature operating environments and heavy-duty industrial connections.
As the undisputed industrial and economic powerhouse of Central Asia, Kazakhstan is undergoing a massive modernization of its energy extraction networks, mineral processing plants, and urban infrastructure. With key oil & gas megaprojects situated in the Caspian basin—such as the expansion of the Tengiz field (Future Growth Project-Wellhead Pressure Management Project), Kashagan offshore production, and Karachaganak condensate processing—the demand for standardized, reliable flange connections has reached an unprecedented scale.
A plain flange (frequently referred to as a plate flange, flat flange, or slip-on welding plate flange) serves as an indispensable connecting element across these pipeline networks. Unlike high-pressure weld neck flanges reserved for severe cyclic loading, plain flanges provide an exceptional balance of structural rigidity, ease of field installation, and cost efficiency in low-to-medium pressure applications (PN6 to PN40 / Class 150 to Class 300).
Information Gain Insight: Operating pipelines in Kazakhstan requires overcoming extreme continental environmental challenges. Temperatures in northern regions like Astana and Kostanay plunge below -40°C to -50°C in winter, while western desert zones experience intense summer heat exceeding +40°C. Standard carbon steel plate flanges often fail under thermal shock or low-temperature brittle fractures unless manufactured with strict grain-refinement heat treatments and impact-tested steel grades such as 09G2S (09Г2С) or ASTM A350 LF2 Class 1.
The procurement profile for plain flanges in Kazakhstan spans across five core industrial pillars:
Gathering lines, low-pressure separators, produced water treatment systems, and auxiliary utility piping at Atyrau, Aktau, and Tengiz processing facilities.
Municipal combined heat and power (CHP) modernization projects in Astana, Almaty, and Karaganda requiring GOST 12820-80 flat welded flanges for hot water distribution.
Heavy slurry pipelines, copper leach systems, and tailing transport lines operated by industry giants in Balkhash, Jezkazgan, and East Kazakhstan.
A comprehensive technical matrix comparing international plate flange standards commonly specified in Kazakhstan engineering projects.
| Standard Ref. | Flange Type Description | Nominal Size (DN / NPS) | Pressure Class | Common Metallurgical Grades | Sub-Zero Impact Compliance |
|---|---|---|---|---|---|
| GOST 12820-80 | Flat Welded Steel Flanges | DN 15 – DN 2400 | PN 1.0 to PN 25 bar (0.1–2.5 MPa) | St3sp, 20, 09G2S (09Г2С), 12X18H10T | 09G2S tested at -50°C (Charpy-V ≥ 27J) |
| EN 1092-1 Type 01 | Plate Flange for Welding | DN 10 – DN 2000 | PN 2.5 to PN 40 | P245GH, P280GH, S235JR, 1.4404 / 316L | Option sub-zero testing down to -40°C |
| ASME B16.5 Plate/SO | Slip-On Plain / Plate Flange | 1/2" – 24" (Up to 60" B16.47) | Class 150 to Class 300 | ASTM A105, A350 LF2, A182 F304/F316L | A350 LF2 Class 1 certified for -46°C |
| DIN 2576 / DIN 2502 | Flat Flanges for Welding | DN 10 – DN 1000 | PN 10 (DIN 2576) / PN 16 (DIN 2502) | RSt 37-2, C22.8, 1.4301 | Standard ambient to -20°C |
Established in 1992 in Dingxiang County, Shanxi—globally recognized as the official "Hometown of Forging in China"—Shanxi Yuxin Casting & Forging Co., Ltd. operates a fully integrated manufacturing facility spanning forging, heat treatment, precision CNC machining, and automated metallurgical testing.
Our Industry 4.0 Smart Production Line ensures that every plain flange exported to Kazakhstan possesses structural uniformity, zero internal porosity, and exact dimensional compliance. By utilizing closed-die forging and ring-rolling technology rather than cheap flame-cut plate metal, our plain flanges deliver superior mechanical properties under high pressure and thermal cycling.
Direct freight train loading from Shanxi to Almaty, Khorgos, and Atyrau, reducing transit times to just 7–12 days compared to 40+ days via maritime freight.
100% heat number mapping with Mill Test Certificates covering spectrographic chemical analysis, mechanical tensile/yield testing, and sub-zero impact reports.
Full support for EAC documentation, GOST-R compliance, and GOST 12820 dimensional standards required across the Eurasian Economic Union.
Field-proven plain flange deployments engineered for extreme environmental operational conditions.
Operating Conditions: Operating temperatures reaching 130°C hot water/steam at PN10 to PN25 pressures, with external winter air temperatures dropping to -45°C.
Engineering Solution: GOST 12820-80 flat welded plain flanges forged from normalized 09G2S (09Г2С) alloy steel. Each flange features a rust-inhibitive yellow or black anti-corrosion varnish coating to prevent moisture degradation during seasonal shut-downs.
Operating Conditions: Low-pressure gas separation lines, flare utility systems, and hydrocarbon storage tank flanges exposed to saline marine winds and H2S traces.
Engineering Solution: Plain flanges compliant with ASME B16.5 Class 150/300 forged from ASTM A350 LF2 Class 1 steel with full NACE MR0175 / ISO 15156 sour service compliance and 100% Ultrasonic Testing (UT) to prevent Hydrogen-Induced Cracking (HIC).
Operating Conditions: High velocity, abrasive mineral slurries requiring fast line dismounting for liner inspection and flange cleaning.
Engineering Solution: Heavy-wall EN 1092-1 Type 01 plain plate flanges manufactured with customized inner bore dimensions to accommodate internal rubber or polyurethane protective liners without restricting slurry flow dynamics.
Operating Conditions: Corrosive chemical reagents, acidic fluid transfer, and high purity nitrogen purge lines.
Engineering Solution: Dual-certified SS304/304L and SS316/316L plain flanges machined with precision serrated Raised Face (RF) finish (125-250 AARH) for optimal gasket sealing and zero leak rate compliance.
Explore our complete inventory of forged flanges, tube sheets, and specialized piping components available for direct overland shipment to Central Asia.
Technical guidance, logistics clarifications, and standard compatibility details for engineers and procurement managers.
We manufacture plain/flat flanges fully compliant with GOST 12820-80 (Flat Welded Flanges) as well as GOST 33259-2015. Dimensions, bolt hole pitch circles, and facing heights strictly match GOST specifications. Furthermore, we supply equivalent steel grades such as 09G2S (09Г2С) for low-temperature applications and St3sp / Steel 20 for standard utility piping, accompanied by EAC certificates and EN 10204 3.1 material documentation.
For operating environments where ambient temperatures fall below -20°C (such as in Astana, Pavlodar, or Kostanay), standard carbon steel like A105 or Q235B is susceptible to embrittlement. We strongly specify normalized low-alloy steels such as 09G2S (09Г2С) or ASTM A350 LF2 Class 1. These grades undergo Charpy V-Notch impact testing at -46°C to -50°C, guaranteeing minimum impact energy absorption of ≥27 Joules.
Thanks to direct overland rail connections via the Horgos and Alashankou land ports, shipments from our Shanxi forging plant reach major Kazakhstan hubs (such as Khorgos, Almaty, Shymkent, and Atyrau) within 7 to 12 days post-customs dispatch. This provides a significant timeline advantage over sea shipments which typically take 35–45 days.
Yes. In addition to standard GOST, EN 1092-1, ASME B16.5, and DIN plain flanges, our CNC machining center manufactures custom non-standard plate flanges up to 3,000 mm (120 inches) in diameter. Send us your CAD drawings (DWG/STEP/PDF), and our engineering team will provide a comprehensive technical proposal within 24 hours.
Every shipment is backed by a comprehensive EN 10204 3.1 Mill Test Certificate (3.2 third-party inspection available via TÜV, SGS, or Lloyd's Register upon request). The test report bundle includes raw material heat analysis, chemical composition, mechanical tensile/yield/elongation values, hardness tests, Charpy-V impact results, Ultrasonic Inspection (UT) reports, and dimensional inspection sheets.
To withstand humidity and harsh transit conditions, all plain flanges undergo surface passivating treatment, followed by customer-specified anti-corrosion coating: clear rust-preventive oil, yellow varnish, black anti-rust paint, or hot-dip galvanizing. Flange sealing faces are protected with plastic end caps or wooden covers, and packed in fumigation-free ISPM-15 compliant plywood cases or steel crates.
Looking for reliable plain flange manufacturers compliant with GOST & EN standards? Get factory-direct pricing, certified material quality, and rapid rail delivery to Central Asia.
