Explore our primary inventory of ASME/ANSI, EN, and custom-engineered blind and pipe flanges manufactured by Shanxi Yuxin Casting & Forging Co., Ltd.
Established in 1992 in Dingxiang County, Shanxi—recognized globally as China’s "Hometown of Forging"—Shanxi Yuxin Casting & Forging Co., Ltd. delivers vertically integrated forging excellence. Every blind flange is heated, forged, heat-treated, CNC-machined, and inspected in-house.
A definitive technical breakdown of blind flange structural mechanics, pressure boundaries, facing geometry, and material specifications for EPC procurement teams and piping engineers.
Unlike standard slip-on or weld neck flanges, a blind flange (BLFF / BLRF) contains no center bore. It functions as a removable pressure-retaining disk designed to seal line terminations, pressure vessel nozzles, and future extension tie-ins. The structural design must withstand maximal bending stress at the center of the plate, induced by internal hydrostatic pressure load combined with high bolt-tightening preloads.
We manufacture blind flanges adhering strictly to global standards including ASME B16.5 (NPS 1/2" to 24"), ASME B16.47 Series A & B (NPS 26" to 60"), EN 1092-1 Type 05 (DN10 to DN4000), DIN 2527, JIS B2220, and GOST 12836. Pressure ratings range from Class 150 to Class 2500, and PN6 to PN400.
Sealing performance relies on exact surface finish matching. We supply Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ), Male & Female (M&F), and Tongue & Groove (T&G). Stock finishes are machined with spiral or concentric serrations at 125–250 µin AARH (3.2–6.3 µm Ra) for standard gaskets, or smooth finishes (< 63 µin AARH) for metallic O-rings.
| Standard | Flange Type | Nominal Size Envelope | Pressure Ratings | Primary Material Alloys Available |
|---|---|---|---|---|
| ASME B16.5 | Blind (BL), Hubbed Blind | NPS 1/2" – 24" (DN15 – DN600) | Class 150, 300, 400, 600, 900, 1500, 2500 | ASTM A105, A350 LF2, A182 F304/L, F316/L, F51, F53 |
| ASME B16.47 Ser. A/B | Large Diameter Blind Flange | NPS 26" – 60" (DN650 – DN1500) | Class 75, 150, 300, 400, 600, 900 | ASTM A105N, A350 LF2 Class 1, A182 F11/F22/F316L |
| EN 1092-1 | Type 05 (Blind Flange) | DN10 – DN3000 | PN6, PN10, PN16, PN25, PN40, PN63, PN100 | P245GH, P280GH, P250GH, 1.4404, 1.4462, S235JR |
| DIN 2527 | Blind Flanges (Blindflansche) | DN10 – DN1000 | PN6 to PN100 | RSt37-2, C22.8, 1.4301, 1.4571 (316Ti) |
| JIS B2220 | Blind Flange (BL-FF / BL-RF) | 10A – 1500A | 5K, 10K, 16K, 20K, 30K | SFVC2A, SS400, SUS304, SUS316, SUS316L |
Analyzing global buyer search intent across energy, chemical processing, offshore marine, and renewable infrastructure to deliver specialized industrial flange configurations.
Intent Focus: High pressure isolation, NACE MR0175 compliance, RTJ facing integrity.
Wellhead Christmas trees, manifold lines, and high-pressure gas gathering networks require blind flanges capable of handling cyclic stress and sour gas containment. Shanxi Yuxin supplies heavy-wall forged blind flanges in ASTM A350 LF2 (low temperature) and ASTM A182 F51 Duplex steel with 100% NACE hardness testing guarantees.
Intent Focus: High temperature resistance, aggressive corrosion allowance, custom tapped bosses.
Refinery distillation columns and hydrocrackers utilize blind flanges with integrated tapped holes (1/2" or 3/4" NPT) for pressure testing, venting, or drain valve tie-ins. Materials like ASTM A182 F11/F22 chrome-moly steel ensure long-term thermal creep resistance up to 600°C.
Intent Focus: Ultra-low temperature toughness (-196°C), zero-leakage gas tightness.
Cryogenic LNG storage tanks and high-pressure hydrogen transport lines mandate tight grain structure and Charpy V-notch impact testing down to -196°C. Our forged austenitic stainless steel (ASTM A182 F316L/1.4404) blind flanges pass helium leak testing and strict grain-size verification.
Providing clear information gain: Detailed forging ratios, heat treatment control, and non-destructive examination protocols for quality assurance.
Every blind flange is produced from fully killed steel billets subjected to a minimum forging reduction ratio of 4:1. Hydraulic pressing and ring rolling align the internal metal grain flow along the circumferential contour of the flange face, yielding far superior impact toughness and fatigue resistance compared to plate-cut disks.
To eliminate internal stresses and homogenize mechanical properties, all carbon steel forgings undergo Normalized heat treatment. Alloy and stainless steel blind flanges undergo Solution Annealing (1050°C+ rapid water quench) or Tempering per ASTM A961/A961M specifications, ensuring optimal corrosion resistance and ductile-to-brittle transition control.
100% of high-pressure blind flanges (Class 600 and above) undergo non-destructive examination (NDE). Ultrasonic Testing (UT per ASTM A388) verifies volumetric sound integrity, while Magnetic Particle Testing (MT) or Liquid Penetrant Testing (PT) guarantees surface defect-free condition prior to anti-rust coating.
| Material Grade | UNS / EN Standard | Yield Strength (MPa) | Tensile Strength (MPa) | Impact Test Requirements | Target Application |
|---|---|---|---|---|---|
| ASTM A105 | K03504 / Carbon Steel | ≥ 250 | 485 – 655 | 27J at 0°C (when normalized) | General ambient industrial piping & steam lines |
| ASTM A350 LF2 Cl.1 | K03011 / LTCS | ≥ 250 | 485 – 655 | ≥ 20J at -46°C | Low-temperature gas processing & Arctic projects |
| ASTM A182 F316L | S31603 / 1.4404 | ≥ 170 | ≥ 485 | ≥ 60J at -196°C | Acid processing, marine, chemical & LNG headers |
| ASTM A182 F51 | S31803 / 1.4462 Duplex | ≥ 450 | 620 – 880 | ≥ 80J at -40°C | High-salinity offshore, subsea & sour oil wells |
| ASTM A182 F11 Cl.2 | K11572 / Alloy Steel | ≥ 275 | 485 – 655 | Per project requirement | High-temperature power plants & boilers |
Adapting next-generation intelligent manufacturing, automated dimensional verification, and green heating technology to redefine international flange export quality.
Our machine shop utilizes multi-axis CNC vertical turning lathes (VTL) equipped with real-time laser tool setters. Bolt hole pitch circles (PCD) and flange face concentricity are machined to tolerances tighter than ASME B16.5 standards (+/- 0.5mm), eliminating bolt binding during field alignment.
To withstand long sea-freight transport and harsh atmospheric storage, we apply customized surface protection including clear anti-rust oil, yellow transparent varnish, black rust-inhibiting paint, hot-dip galvanizing (HDG per ASTM A153), or fusion-bonded epoxy (FBE) coatings.
Transitioning from coal to medium-frequency electric induction billet heaters has reduced carbon emissions per ton of forging by over 35%. Precise temperature control prevents billet overheating and decarbonization, ensuring consistent raw structural density.
Comprehensive certification compliance tailored for European, North American, Middle Eastern, and Asian EPC project requirements.
Shanxi Yuxin Casting & Forging Co., Ltd. operates under an audited quality management system compliant with ISO 9001:2015, European Pressure Equipment Directive PED 2014/68/EU, and AD 2000-Merkblatt W0 / TRD 100. Our products carry CE marking where mandated.
Every single shipment is accompanied by a certified EN 10204 3.1 Mill Test Certificate (MTC) detailing chemical heat analysis, mechanical yield/tensile/elongation values, hardness, impact test data, and heat treatment batch details. Independent third-party inspection (TVI via SGS, BV, TÜV, DNV) for EN 10204 3.2 certification is regularly arranged.
To eliminate damage during international ocean transport, flanges are protected with plastic end-caps, interleaved with moisture barrier paper, and packed inside heavy-duty, fumigation-free ISPM-15 compliant plywood cases or reinforced steel-frame pallets.
Review our companion line of ASME B16.47 weld neck flanges, reducer flanges, stub ends, and CNC-drilled heat exchanger tube sheets.
Engineering answers to critical procurement, manufacturing capability, and specification questions regarding blind flanges and forged pipe fittings.
