Direct-factory pricing on ISO 9001 and PED 2014/68/EU certified forged flanges engineered for high-pressure, critical fluid measurement and piping isolation.
An exhaustive analysis of differential pressure metering geometry, stress distribution, tap hole machining tolerances, and ASME B16.36 specifications.
Orifice weld neck flanges feature paired differential pressure taps (typically 1/2" NPT or socket weld) drilled directly through the flange ring at exact 1-inch (25.4 mm) distances from the flange face, eliminating pipeline tapping errors and ensuring compliance with ISO 5167 and AGA-3.
Designed with machined jack-screw slots and heavy hex jack bolts. This allows plant technicians to easily separate the flange pair during maintenance routines for orifice plate replacement, inspection, or cleaning without risking damage to the gasket sealing surfaces.
The long, gradual taper from the flange hub down to the pipe weld bevel reduces stress concentration at the joint root. This structural neck transfers mechanical strain into the pipe wall, mitigating thermal fatigue and vibration damage in high-pressure loops.
According to ASME B16.36, the internal bore of an Orifice Weld Neck Flange must match the exact inner diameter (ID) of the adjacent pipe schedule (e.g., Sch 40, Sch 80, Sch 160, XXS). Any step discontinuity between the flange bore and pipe bore creates turbulent eddies, distorting the flow profile and compromising differential pressure (ΔP) flowmeter calculation accuracy. Our CNC machining process maintains bore tolerance within ±0.127 mm (±0.005 in).
| Specification Parameter | ASME B16.36 Class 300 / 600 | ASME B16.36 Class 900 / 1500 / 2500 | EN 1092-1 / DIN Equivalent |
|---|---|---|---|
| Nominal Size Range | 1" to 24" (DN25 – DN600) | 1" to 12" (DN25 – DN300) | DN15 to DN1000 |
| Pressure Tap Type | 1/2" NPT Female Threaded or Socket Weld | 1/2" NPT Female / High-Pressure Autoclave | Corner Taps or Annular Chamber Taps |
| Facing Options | Raised Face (RF), Flat Face (FF) | Ring Type Joint (RTJ - R, RX, BX) | Type B1 / B2 Facing, Type D Groove |
| Flange Face Finish | Serrated Concentric / Spiral (125–250 AARH) | Smooth Finish (<63 AARH) for RTJ Gaskets | Ra 3.2 to 6.3 μm (Custom Available) |
| Standard Materials | ASTM A105, A350 LF2, A182 F304/F316L | ASTM A182 F11, F22, F51, F53, Inconel 625 | P250GH, 1.4404, 1.4462 Duplex Steel |
Leveraging the manufacturing scale of Dingxiang, Shanxi — China's premier forging capital — to deliver wholesale discount flange solutions with uncompromised quality control.
Our facility houses 5,000-ton and 10,000-ton hydraulic forging presses paired with CNC ring-rolling mills. Closed-die forging shapes refined grain structures that align perfectly with the contour of the flange neck. This optimal grain orientation eliminates internal porosity, dramatically increasing tensile yield strength and fatigue limits under cyclical thermal stress.
Every single batch of discount flange orifice welding neck products undergoes non-destructive testing (NDT), including Ultrasonic Testing (UT per SEP 1921 / ASME Sec V) to detect internal lamination defects, Magnetic Particle Inspection (MT), Positive Material Identification (PMI spectrometry), and 3D Optical CMM dimensional verification prior to surface coating.
Engineered for extreme operating environments across energy, petrochemical, marine, and power generation infrastructure worldwide.
Specified for high-pressure natural gas custody transfer and crude oil metering. Supplied with NACE MR0175 / ISO 15156 H2S resistance and low-temperature impact testing down to -46°C (ASTM A350 LF2 Class 1).
Resistant to high-temperature hydrocarbon cracking and aggressive acids. Material options include ASTM A182 F11, F22 chrome-moly alloys and F316L stainless steel engineered for long-term corrosion allowance.
Utilized in high-pressure steam headers and feed-water loops. Precision bored and heat-treated under normalized, quenched, and tempered cycles to handle intense thermal shock and pressure cycles.
Austenitic stainless steels (F304L, F316L) and nickel alloy forgings designed for sub-zero liquid natural gas transport systems, preserving notch toughness at -196°C temperatures.
Custom low-permeability forged components built to contain volatile hydrogen molecules. Features ultra-fine surface roughness finishes to eliminate micro-leak paths across metallic gaskets.
Compact, high-integrity Ring-Type Joint (RTJ) orifice weld necks certified by DNV, ABS, and Lloyd's Register for space-constrained marine skid systems subjected to wave motion stresses.
Pioneering smart flange assemblies, additive-forging hybrid metallurgy, and computational fluid dynamics (CFD) optimization for Industry 5.0 efficiency.
Development of smart orifice flange assemblies embedded with micro-piezoresistive pressure transducers and IoT wireless telemetry nodes. Enables real-time ΔP monitoring, predictive erosion tracking, and automated leakage detection without external impulse piping.
Utilizing high-speed Laser Cladding Additive Manufacturing (LCAM) to deposit Inconel 625 or Hastelloy C-276 anti-corrosive alloys directly onto low-cost carbon steel forged bases, delivering high alloy performance at a fraction of solid alloy material costs.
Combining finite element analysis (FEA) and computational fluid dynamics (CFD) to optimize internal tap entry radiuses and annular pressure chamber channels, minimizing discharge coefficient uncertainty and extending orifice plate operational life.
Total Cost of Ownership (TCO) optimization, strict quality documentation, and seaworthy packaging protocols tailored for international EPC contractors.
Every steel billet is inspected upon arrival. Low-carbon and alloy heats are verified via optical emission spectrometers. Continuous die-stamping ensures the raw heat number stays visible on the flange outer rim throughout forging, heat treatment, and final machining.
Complete documentation standard for export shipments: chemical ladle analysis, mechanical tension tests (Yield, Tensile, Elongation), Charpy V-Notch impact values at specified sub-zero temperatures, heat treatment charts, and hardness test values (HBW/HRC).
Flange faces receive a heavy application of transparent rust-preventive varnish or rust-inhibitive oil, fitted with plastic end covers for tap protection, wrapped in VCI corrosion-inhibitor film, and packed inside steel-strapped, ISPM-15 compliant fumigation-free plywood cases.
Cross-reference matrix enabling engineering teams to select direct equivalent flange specifications for international projects.
| International Region | Primary Flange Standard | Pressure Ratings Covered | Key Compliance & Regulatory Approvals |
|---|---|---|---|
| North America (US / Canada) | ASME B16.36, ASME B16.5, MSS SP-44 | Class 300, 600, 900, 1500, 2500 | CRN (Canadian Registration Number), API 6A |
| European Union (EU) | EN 1092-1 (Type 11 Weld Neck / Type 05) | PN10, PN16, PN25, PN40, PN63, PN100 | PED 2014/68/EU CE Marking, AD 2000-Merkblatt W0 |
| United Kingdom (UK) | BS 4504 / BS 10 Tables | Table D, E, F, H / PN Equivalent | UKCA Pressure Equipment Safety Regulations |
| Japan & APAC | JIS B2220 / KS B1503 | 10K, 16K, 20K, 30K, 40K, 63K | JIS Mark Certification, ISO 9001:2015 |
| Eurasian Economic Union | GOST 12821-80 / GOST 33259-2015 | PN 1.6 MPa to PN 25.0 MPa | EAC TR CU 032/2013 Compliance Certificate |
Explore our broader spectrum of precision-machined industrial piping components designed for immediate bulk shipment and OEM dynamic customization.
Clear engineering answers regarding orifice flange specification, differential pressure taps, installation standards, and factory direct procurement.
