custom API 6A High Pressure Blind Flange - Precision Machined
Product Description
1. Product Overview
Blind flange, also named blank flange or blind plate, is a solid circular forged component without central through bore. It is bolted onto matching pipe flanges to fully seal pipeline terminals, wellhead outlets, valve ports and equipment branch openings. It realizes temporary fluid isolation for pipeline maintenance, pressure testing, or permanent system shut-off. Unlike welded pipe caps, bolted blind flanges can be quickly disassembled for pipeline inspection, internal cleaning and system expansion without cutting pipe sectionsMade-in-Ch....
Our blind flanges are integrally forged and precision CNC machined, fully compliant with international industrial standards for oil & gas, chemical and power industries. Multiple material grades, sealing face types and pressure classes are available to match low, medium and ultra-high pressure working media, including corrosive fluid, high-temperature steam and wellhead crude/gas.
2. Core Working Principle
The flat sealing surface of blind flange closely fits standard gaskets (metal spiral, ring joint gasket) under uniform bolt tightening force, forming a fully leak-tight barrier to block internal fluid flow. Even under fluctuating high pressure and temperature, the solid thick forging structure maintains stable sealing without deformation or medium leakage.
3. Application Fields
- Oil & Gas: Wellhead assembly, crude transmission pipeline, refinery, natural gas gathering pipeline, high-pressure manifold
- Petrochemical & Chemical: Corrosive medium pipeline, reactor outlet, chemical storage tank shut-off port
- Power Plant: Steam pipeline, boiler auxiliary pipe, cooling water system isolation
- Water Treatment & HVAC: Municipal pipeline, industrial sewage system, pressure vessel end closure
- Heavy Industry: Mining fluid pipeline, marine offshore piping, hydraulic high-pressure system
Product Features
- One-piece solid forging structure, high tensile strength, anti-deformation under extreme high pressure
- Three universal sealing face designs to adapt all pipeline gasket types, zero leakage sealing performance
- Full range material options, covering anti-low-temperature, anti-acid-corrosion, high-temperature resistant working conditions
- Strict compliance with API 6A & ASME industrial standards, qualified for oilfield wellhead critical equipment
- Uniform bolt hole distribution with precise drilling, consistent bolt pre-tightening force for stable long-term sealing
- Detachable bolted installation, convenient for pipeline maintenance, inspection and system reconstruction
- Complete size & pressure stock, fast delivery for standard models; OEM custom drawing processing available
- Complete material test certificates and third-party inspection reports provided for industrial project bidding
- Strong temperature adaptability: Works steadily from -46℃ low temperature to 550℃ high temperature environment
- Long service life, anti-oxidation and anti-medium erosion, reduces pipeline system maintenance frequency
Product Specifications
| Parameter Category | Specification Item | Available Options / Description |
|---|---|---|
| Manufacturing Standards | Main Compliance | ASME/ANSI B16.5, ASME B16.47 (Series A/B), API 6A, EN 1092-1, DIN, JIS |
| Certifications | ISO 9001, API PR2 Low Temperature Certification, Material Test Report (MTC), Third-Party Inspection | |
| Material Grades | Carbon Steel | A105, A350 LF2 (Low Temperature), A694 F52/F65/F70 |
| Stainless Steel | A182 F304, F304L, F316, F316L, F321 | |
| Duplex Steel | A182 F51 (2205), F53 (2507) | |
| Alloy Steel | A182 F11, F22, F91, Monel 400, Inconel 625 | |
| Nominal Size | Inch (NPS) | 1/2" ~ 48" (Full Standard Range) |
| Metric (DN) | DN15 ~ DN1200 (Full Standard Range) | |
| Customization | Non-standard size, thickness and bolt hole design per client drawings | |
| Pressure Ratings | ASME Class Series | Class 150#, 300#, 600#, 900#, 1500#, 2500# |
| PN Metric Series | PN16, PN25, PN40, PN63, PN100, PN160, PN250, PN420 | |
| API 6A Wellhead Pressure | 2000PSI, 3000PSI, 5000PSI, 10000PSI | |
| Sealing Face Types | RF (Raised Face) | Standard general type, for low & medium pressure applications |
| FF (Flat Face) | For low-pressure non-toxic fluid, matches full-face gaskets | |
| RTJ (Ring Joint Groove) | For high-pressure & high-temperature severe service, API wellhead preferred | |
| Surface Finishes | Standard Machined | CNC machined finish for general industrial use |
| Stainless Steel Options | Mirror polishing, pickling & passivation | |
| Anti-Corrosion Coatings | Black anti-rust primer, epoxy anti-corrosion primer | |
| Machining & Inspection | Precision Tolerance | CNC machining, bolt hole position tolerance ±0.1mm, sealing surface roughness Ra ≤3.2μm |
| Standard Tests | Chemical composition analysis, mechanical tensile/impact test, ultrasonic flaw detection, hardness test, hydraulic leak test |