Lap Joint Flange (Loose Flange)
Yunming Metal supplies stainless steel lap joint flanges (loose flanges) in sizes DN15–DN3000. Designed for removable pipeline systems using stub ends, they comply with ANSI, EN, and JIS standards and are available in 304, 316L, 321, and duplex steel.
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Product Overview
Lap joint flanges, also known as loose flanges, are designed to be used with stub ends and allow easy alignment and rotation after welding. Since the flange is not welded directly to the pipe, it is especially suitable for applications requiring frequent disassembly, inspection, or alignment. Stainless steel lap joint flanges are corrosion-resistant and easy to install, making them ideal for non-critical, low to medium pressure piping systems. Available in sizes DN15 to DN3000 and compatible with ANSI, EN, and JIS standards.
Application Areas
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Chemical and pharmaceutical processing
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Food and beverage manufacturing
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Water treatment and environmental systems
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Marine and shipbuilding pipelines
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Tank nozzles and heat exchanger connections
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Hygienic or clean-in-place (CIP) systems requiring frequent inspection
Product Features
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Used with short or long stub ends for detachable pipe connections
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Allows free rotation for easy bolt alignment
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Ideal for non-welded joints in corrosive or vibrating environments
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Suitable for Class 150 to 2500 and PN6 to PN100 pressure ratings
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Manufactured in 304, 316L, 321, 310S, 904L, duplex, and other grades
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Available in raised face (RF) or flat face (FF)
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Complies with ANSI B16.5, EN 1092-1, JIS B2220, DIN, and ISO standards
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Smooth CNC-machined surface for gasket sealing
Technical Specifications
| Parameter | Range |
|---|---|
| Nominal Size (DN) | DN15 – DN3000 |
| Outside Diameter (OD) | 34 mm – 3200 mm (approx. 1⁵⁄₁₆″ – 126″) |
| Thickness (T) | 9 mm – 120 mm (approx. ³⁄₈″ – 4¾″) |
| Stub End Type | Short stub end / Long stub end / Custom sizes |
| Pressure Ratings | Class 150 – Class 2500 / PN6 – PN100 |
| Material Grades | ASTM A182 F304 / F316 / F316L / F321 / 904L / 2205 etc. |
| Standards | ANSI B16.5, EN 1092-1, JIS B2220, DIN, BS, ISO |
| Type | Lap Joint Flange (Loose Flange), RF or FF face |
| Connection Type | Slide-on and rotate over stub end |
| Surface Finish | CNC machined, anti-rust oil coating |
| Application | Piping systems requiring removable and adjustable connections |
Manufacturing Process
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Raw Material Preparation – Cut stainless steel plates or billets to size
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Forging or Machining – Form flange rings through hot forging or turning
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CNC Machining – Drill bolt holes, gasket surfaces, and inner bore
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Surface Finishing – Apply anti-rust treatment and optional polishing
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Inspection & Marking – Check dimensions, flatness, and mark per standard
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Packaging – Pack with moisture protection for safe international delivery
FAQ
Q1: What’s the benefit of lap joint flanges over weld neck flanges?
A: They are not welded to the pipe, allowing rotation for easier bolt hole alignment and disassembly.
Q2: Can lap joint flanges handle high pressure?
A: They are mainly used for low to medium pressure systems. For high pressure, use weld neck types.
Q3: Do you provide matching stub ends?
A: Yes. We supply short and long stub ends matched to lap joint flanges.
Q4: What sizes and standards are available?
A: Sizes range from DN15 to DN3000. Standards include ANSI B16.5, EN 1092-1, JIS B2220, and ISO.
Q5: What materials are suitable for corrosive environments?
A: Grades like 316L, 904L, and duplex 2205 are ideal for corrosive applications.
Still have questions?
Feel free to contact us for more details or to discuss your custom stainless steel loose flange requirements. Our technical support team is ready to assist with specifications, certifications, and delivery.
