Description
Product Detail
AL6XN lap joint flanges are backing flanges designed to work with lap joint stub ends, allowing the flange to rotate freely for easy bolt alignment during installation. Manufactured in high-alloy 6-moly super austenitic stainless steel, they are widely used in seawater, brine, flue gas desulfurization, pulp and paper, offshore and chemical processing systems where superior resistance to pitting, crevice corrosion and chloride stress corrosion cracking is required.
SASA FLANGE supplies AL6XN lap joint flanges in standard and custom sizes to ASME, EN, DIN, JIS and GB dimensions. Each batch can be provided with chemical analysis, mechanical testing, dimensional inspection and PMI verification. We also offer machining to suit matching stub ends, with EN 10204 3.1 certificate, clear heat number identification and full material traceability for critical industrial projects.
- ✓Product Name: AL6XN Lap Joint Flange
- ✓Material Grade: AL-6XN / UNS N08367 super austenitic stainless steel
- ✓Product Type: Loose lap joint backing flange for use with stub end
- ✓Main Feature: Excellent pitting and crevice corrosion resistance with easy alignment and maintenance
- ✓Applications: Seawater systems, chemical processing, offshore piping, desalination, power and water treatment
Product Parameters
| Product Name | AL6XN Lap Joint Flange |
| Material Grade | AL-6XN / UNS N08367, 6Mo super austenitic stainless steel |
| Material Type | High-alloy corrosion-resistant stainless steel forging or plate-machined material |
| Product Form | Lap Joint Flange / Loose Backing Flange |
| Size Range | DN15 – DN600 (1/2 inch – 24 inch) |
| Pressure Class | Class 150 – 600 / PN10 – PN40 |
| Sealing Face | Flat face lap joint type, used with raised face or lap joint stub end sealing surface |
| Surface Treatment | Pickling, passivation, machined finish, protective oil on machined surfaces |
| Standard | ASME B16.5, EN 1092-1, DIN, JIS B2220, GB/T 9119 or customer specification |
| Inspection | Chemical Analysis, Mechanical Test, PMI Test, Dimensional, Visual and Surface Inspection |
| Certificate | EN 10204 3.1 Material Certificate available |
| Processing Service | Cutting, CNC Machining, Custom Drilling, Custom Size Processing |
Chemical Composition
The following AL6XN chemical composition is for general reference for UNS N08367 material used in lap joint flanges and matching stub ends. Exact composition may vary slightly by melt practice, product form and applicable material standard. Final supplied chemistry shall conform to the relevant specification and the values shown on the mill test certificate.
| Element | C | Si | Mn | P | S | Cr | Ni | Mo | Other |
|---|---|---|---|---|---|---|---|---|---|
| Content % | 0.03 max | 1.00 max | 2.00 max | 0.040 max | 0.030 max | 20.0 – 22.0 | 23.5 – 25.5 | 6.0 – 7.0 | N 0.18 – 0.25, Cu 0.75 max |
Mechanical Properties
Mechanical properties for AL6XN lap joint flanges depend on product form, solution annealing condition, section thickness and the governing material specification. The values below are typical reference data used for engineering review. Final mechanical properties of supplied flanges shall be confirmed by the applicable material standard and certified test results.
| Grade | Tensile Strength | Yield Strength | Elongation | Hardness | Density |
|---|---|---|---|---|---|
| AL-6XN / UNS N08367 | 690 MPa min | 310 MPa min | 35% min | 95 HRB max | 8.24 g/cm3 |
| AL-6XN Solution Annealed | 720 MPa typical | 345 MPa typical | 40% typical | 220 HB max | 8.24 g/cm3 |
Common Size Table
| Size Range | Pressure Class | Sealing Face | Material | Availability |
|---|---|---|---|---|
| DN15 – DN50 | Class 150 – 300 | Lap Joint | AL-6XN / UNS N08367 | Stock / Production |
| DN65 – DN300 | Class 150 – 600 | Lap Joint | AL-6XN / UNS N08367 | Stock / Production |
| DN350 – DN600 | Class 150 – 600 | Lap Joint | AL-6XN / UNS N08367 | Production |
| DN15 – DN600 | PN10 – PN40 | Lap Joint | AL-6XN / UNS N08367 | Made to Order |
Different Specifications Comparison
| Type | Description | Typical Use |
|---|---|---|
| ASME Lap Joint Flange | Loose backing flange per ASME B16.5 used with lap joint stub end | Process piping in chemical, offshore and desalination plants |
| EN Lap Joint Flange | Lap joint backing flange to EN 1092-1 with matching collar or stub end | European standard pipelines for water, chemical and utility systems |
| Plate-Machined AL6XN Lap Joint Flange | Machined from corrosion-resistant plate for special dimensions or low volume orders | Custom projects and non-standard piping systems |
| Forged AL6XN Lap Joint Flange | Produced from forged or rolled ring material for improved structure and strength | Critical corrosive service and higher reliability installations |
Equivalent Standards and International Names
Lap joint flange dimensions are governed by international flange standards, while AL6XN is a proprietary 6-moly super austenitic stainless steel commonly designated as UNS N08367. Equivalent naming may vary by region, but project documents usually specify UNS N08367, AL-6XN or 6Mo stainless. Dimensional standards should always be confirmed separately from the alloy grade designation.
| Standard / Region | Standard Code | Typical Grade / Equivalent |
|---|---|---|
| USA | ASME B16.5 | AL-6XN / UNS N08367 lap joint flange |
| Europe | EN 1092-1 | 6Mo / UNS N08367 equivalent project-specified material |
| Germany | DIN 2527 / 2566 | Special alloy lap joint flange in 6Mo super austenitic stainless |
| Japan | JIS B2220 | Equivalent high-alloy stainless lap joint flange by customer specification |
| China | GB/T 9119 | UNS N08367 / AL-6XN equivalent custom material |
Production Process Flow
SASA FLANGE applies controlled manufacturing and inspection procedures for AL6XN lap joint flanges to maintain corrosion resistance, dimensional accuracy and material traceability throughout production.
- 1. Raw Material Selection
- 2. Forging / Cutting
- 3. Heat Treatment
- 4. Rough Machining
- 5. Finish Machining
- 6. Drilling
- 7. Surface Treatment
- 8. Inspection
- 9. Marking
- 10. Packing
- 11. Delivery
| Process Step | Description | Quality Control Point |
|---|---|---|
| Raw Material | Select certified forging billets or plates | Material certificate and traceability |
| Forging | Hot forging to achieve required shape | Forging temperature and reduction ratio |
| Heat Treatment | Solution annealing as required for AL6XN material | Temperature and holding time control |
| Machining | Seating dimensions, bore, bolt holes and outside diameter | Dimensional accuracy and surface finish |
| Inspection | Final inspection before shipment | Dimension, surface, PMI and marking verification |
Product Inspection
1. Chemical Composition Inspection
Chemical analysis is carried out to verify that the AL6XN material meets UNS N08367 composition requirements, especially chromium, nickel, molybdenum and nitrogen content. This is essential for confirming corrosion resistance in chloride service. Test results are reviewed against the applicable material standard and recorded on the mill test certificate for full traceability.
2. Mechanical Properties Testing
Mechanical testing is performed to confirm tensile strength, yield strength, elongation and hardness of the supplied AL6XN flange material. These checks help ensure the flange can withstand installation loads and operating conditions. Where required, test reports are linked to the heat number so the buyer can verify compliance with project specifications.
3. Dimensional Inspection
Each lap joint flange is inspected for outside diameter, thickness, bore, bolt circle, bolt hole quantity and hole diameter according to ASME, EN or customer drawings. The lap joint seating dimensions are also checked to ensure proper fit with the stub end. Accurate dimensions are critical for smooth assembly and leak-free service.
4. PMI Testing and Hydrostatic Testing
Positive Material Identification is available to confirm the supplied flange is genuine AL6XN / UNS N08367 and not substituted with lower alloy stainless steel. As lap joint flanges themselves are non-pressure-containing loose backing components, hydrostatic testing typically applies to the assembled piping system or matching stub end arrangement. EN 10204 3.1 certificate is provided on request.
Product Packaging
- ✓Wooden Case Packaging: Suitable for high-pressure and large-diameter products
- ✓Pallet Packing with Shrink Wrap: Suitable for batch shipments and standard sizes
- ✓Anti-rust Oil Coating + Waterproof Paper: Used for ocean freight protection
- ✓Individual Plastic Bag + Carton: Used for small fittings and threaded products
- ✓Clear Marking: Grade, size, pressure class, heat number and PO number
Applications
AL6XN lap joint flanges are selected for corrosive piping systems where excellent resistance to chloride attack, pitting and crevice corrosion is required together with easy installation and dismantling. They are especially suitable for use with expensive alloy stub ends, because the rotating backing flange simplifies alignment and can reduce total system cost in demanding industrial environments.
| Industry | Typical Applications | Why This Product Is Used |
|---|---|---|
| Oil and Gas | Produced water lines, offshore utility piping, seawater injection and topside corrosive service | Provides high chloride corrosion resistance and easier field alignment with stub ends |
| Chemical Processing | Acid handling systems, chlorides service, bleach plants and specialty chemical piping | AL6XN offers excellent pitting and crevice corrosion resistance in aggressive media |
| Power Generation | FGD units, cooling water lines and high-chloride auxiliary systems | Used where standard stainless grades may fail in wet chloride environments |
| Water Treatment | Desalination skids, brine transfer lines and reverse osmosis support piping | Suitable for seawater and brine service with reliable long-term corrosion performance |
| Marine and Offshore | Shipboard seawater systems, offshore modules and coastal process plants | Combines superior seawater resistance with convenient maintenance and replacement |
Why Choose SASA FLANGE?
- ✓Professional manufacturer of Lap Joint Flange for global industrial projects
- ✓Customized size, pressure class and material grade according to drawings
- ✓Full standard support: ASME, EN, DIN, JIS, GB, GOST and customer specifications
- ✓Material traceability with heat number control and EN 10204 3.1 material certificate
- ✓Chemical analysis, mechanical testing, PMI testing, hydrostatic and dimensional inspection
- ✓Stock availability for standard items, lead time 3-7 days; custom production 15-30 days
- ✓Export-grade packaging for sea, air and land transportation
- ✓15+ years experience supplying 50+ countries worldwide
FAQ
Q: What is an AL6XN lap joint flange?
A: An AL6XN lap joint flange is a loose backing flange manufactured in UNS N08367 super austenitic stainless steel and used together with a lap joint stub end. The flange rotates around the stub end, which makes bolt alignment easier during installation. It is widely used in corrosive piping systems handling seawater, brine and aggressive chemical media.
Q: What materials are available for AL6XN lap joint flanges?
A: The main material is AL-6XN / UNS N08367, a 6-moly super austenitic stainless steel with high resistance to pitting and crevice corrosion. For project comparison or matching components, SASA FLANGE can also supply related high-alloy stainless and nickel alloy flange products on request, including 904L, duplex, super duplex and selected nickel alloys.
Q: What pressure class is supported?
A: For AL6XN lap joint flanges, the common supply range is ASME Class 150, 300 and 600, with EN ratings such as PN10, PN16, PN25 and PN40 depending on size and standard. Higher ratings may be considered for special projects, but lap joint flange dimensions and availability should be confirmed together with the matching stub end design.
Q: Can SASA FLANGE supply custom sizes?
A: Yes. SASA FLANGE can supply custom AL6XN lap joint flanges according to drawings or project specifications. We support custom drilling, non-standard bolt holes, special outside diameters, special thickness, machining to suit matching stub ends and compliance with ASME, EN, DIN, JIS, GB or end-user dimensional requirements for replacement and OEM applications.
Q: What certificate is provided?
A: SASA FLANGE can provide EN 10204 3.1 material certificate with heat number traceability for AL6XN lap joint flanges. Supporting documents may include raw material MTC, chemical analysis, mechanical test results, dimensional inspection records and PMI verification. Additional third-party inspection can also be arranged according to project requirements before shipment.
Contact Us
If you are looking for al6xn lap joint flanges or related custom flange products, please contact SASA FLANGE with your required size, pressure class, material grade, standard, surface treatment, quantity and inspection requirements. Our team will provide professional technical solutions and competitive quotation within 24 hours.
- 📧 Email: sales@sasaflange.com
- 📱 WhatsApp: +86 13764965049
- ☎️ Tel: +86 21 52236361
- 🌐 Website: www.sasaflange.com
