Lap Joint Pipe Flange
Material: Carbon Steel,stainless steel, alloy steel
Pressure Ratings: Class 150, 300, 400, 600, 900, 1500, 2500.
Size Range: 1/2" – 24" (DN15 – DN600) | Larger sizes available on request.
Facing: Flat Face (FF) – Typical for Lap Joint designs to ensure a smooth backing surface for the stub end.
Surface Finish: Anti-rust Oil, Black Paint, Hot-Dipped Galvanized, or Cold Galvanized.
Application: oil, gas,water/wastewater treatment, industry pipeline,etc.
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- 24/7 Customer Service
Product Introduction
Lap Joint Pipe Flange Manufacturer
Hebei Jinsheng Pipe Fitting Manufacturing Co., Ltd. conveys premium lap joint pipe flange arrangements with over 40 a long time of fabricating greatness. Our cutting edge 7,000+ square meter office produces high-quality spines assembly ASME B16.5 measures from 1/2" to 60" distances across. With demonstrated capacity of 100+ million RMB yearly deals and 50+ holder month to month shipments, we serve worldwide vitality companies over 30+ nations. Our two-component lap joint gatherings highlight precision-machined bore sweep and Course 150-2500 weight evaluations for ideal performance.
Lap Joint Pipe Flange Overview
You'll discover our carbon steel lap joint spines are built as flexible two-component congregations comprising of a free backing flange and coordinating stub conclusion. Not at all like conventional spines, these units slip over your pipe and turn unreservedly, making them idealize when you require visit destroying for cleaning or inspection.
The one of a kind flat-face plan implies the rib doesn't weld straightforwardly to your pipeline. Instep, it sits behind the butt-welded stub conclusion, making a adaptable association that disentangles bolt-hole arrangement in indeed the most challenging installations.


Key Features & Advantages
Fast Jolt Gap Arrangement: Your establishment group will appreciate how our ribs turn unreservedly since they're not welded to the pipe. This include drastically decreases labor hours when adjusting jolt gaps in complex channeling layouts.
Simplified Upkeep Get to: When your framework requires customary inner cleaning or review, you can rapidly dismantle associations without cutting or re-welding the fundamental pipeline.
Superior Push Administration: Our two-piece plan successfully assimilates warm development and vibration stresses way better than unbending choices, expanding your connection's lifecycle in cycling temperature systems.
Economic Adaptability: Since the flange never contacts the liquid, you can utilize our solid carbon steel backing spines with stainless stub closes for destructive media applications.
Reusable Components: Amid framework retrofits, you can evacuate and reuse the backing spine on modern pipe segments, giving long-term operational investment funds.
Technical Specifications
| Parameter | Specification |
|---|---|
| Standards | ASME/ANSI B16.5 (1/2" to 24"), ASME B16.47 (26" to 60") |
| Pressure Ratings | Class 150, 300, 600, 900, 1500, 2500 |
| Face Type | Flat Face (FF) |
| Bore Feature | Precision-machined radius at bore/face intersection |
| Material | Carbon Steel A105, A350 LF2 |
| Temperature Range | -29°C to +427°C (depending on class rating) |
| Surface Finish | Black lacquer, rust-preventative oil, hot-dip galvanized |
Standards & Certifications
Our manufacturing processes strictly adhere to international standards including ASME/ANSI B16.5, ASTM A105, and MSS SP-44. We maintain ISO 9001:2015 certification and comply with CE marking requirements for European markets.
All products undergo rigorous testing using advanced spectrometer analysis and non-destructive testing equipment to ensure material integrity and dimensional accuracy.





Chemical Composition & Mechanical Properties
| Element | A105 Composition (%) |
|---|---|
| Carbon | 0.35 max |
| Manganese | 0.60-1.05 |
| Phosphorus | 0.035 max |
| Sulfur | 0.040 max |
| Silicon | 0.10-0.35 |
Mechanical Properties: Tensile Strength: 485 MPa min, Yield Strength: 250 MPa min, Elongation: 22% min
Manufacturing Process
We utilize precision forging and machining processes to create your flanges. Each unit undergoes controlled heating, forming, and stress-relieving treatments. The critical bore radius receives special attention through CNC machining to ensure perfect mating with stub end fillets.
Quality inspections occur at every stage, from raw material verification through final dimensional checking and surface finish validation.

Surface Finish & Coating Options
You can choose from several protective finishes:
- Standard Black Lacquer: Basic corrosion protection for indoor applications
- Rust-Preventative Oil: Enhanced protection during storage and shipping
- Hot-Dip Galvanized: Superior atmospheric corrosion resistance for outdoor installations
Applications
Our lap joint pipe flange excels in these applications:
- Water treatment facilities requiring frequent cleaning access
- Chemical processing plants with regular inspection needs
- Food and pharmaceutical systems demanding sanitary disassembly
- Marine and offshore installations with space constraints
- Pipeline systems with frequent maintenance requirements

Packaging & Delivery
We protect your investment through careful packaging in wooden cases or steel crates with moisture-resistant materials. Standard delivery runs 15-25 days for stock sizes, with expedited options available for urgent requirements.
Our logistics team coordinates worldwide shipping from major Chinese ports, ensuring safe arrival at your destination.
Customization Service
Beyond standard offerings, we provide custom solutions including:
- Special material grades for extreme service conditions
- Modified bore configurations for unique stub end requirements
- Custom pressure ratings for specific applications
- Specialized coatings for harsh environments
Quality Control
Every flange passes through our comprehensive quality system including material traceability, dimensional verification, and pressure testing when required. We maintain detailed quality records and provide complete mill test certificates with each shipment.

FAQ
Q: What's the difference between Slip-On and flange designs?
A: While similar in appearance, Slip-On flanges weld directly to pipes with raised faces. Lap Joint versions remain loose on pipes with flat faces, requiring stub ends for sealing.
Q: Why is the bore radius critical?
A: The machined radius must match your stub end's fillet radius for proper seating. Incorrect radius leads to misalignment and potential joint failure.
Q: Can these handle high-pressure applications?
A: Yes, we manufacture up to Class 2500 ratings. However, they're most common in Class 150-300 systems due to their design characteristics.
Contact Us
Ready to discuss your lap joint pipe flange requirements? Contact our technical team at admin@jsfittings.com for expert guidance and competitive pricing.
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