SS304 Lap Joint Stub End, Butt Weld Pipe Fitting for Corrosive Resistant Piping

Product Specification

SS304 Lap Joint Stub End, Butt Weld Pipe Fitting for Corrosive Resistant Piping

1. Product Description

SS304 Lap Joint Stub End, Butt Weld Pipe Fitting for Corrosive Resistant Piping is a high-quality butt-weld pipe fitting designed for use with lap joint flanges. Also commonly known as a lap joint stub end, this fitting features one flared end that seats against the flange face and one plain beveled end for butt welding to the pipeline . Manufactured from premium SS304 stainless steel, this stub end offers excellent corrosion resistance and durability for demanding industrial applications. Type A configuration with long taper ensures smooth flow transition and is compatible with standard lap joint flanges .

2. Key Specifications

3. Applications

The SS304 Stub End is widely used in piping systems across multiple industries:

• Oil & Gas – pipeline connections and refineries

• Petrochemical & Chemical Processing – corrosive media handling

• Food & Beverage – sanitary piping systems

• Pharmaceutical – clean and sterile environments

• Water Treatment & HVAC – general industrial piping

• Power Generation – steam and cooling water systems

4. Product Advantages

• Cost-Effective Solution – Only the stub end needs to match the pipe alloy; the lap joint flange can be carbon steel, significantly reducing material costs, especially for large-diameter systems

• Easy Maintenance – The lap joint flange can slide freely over the stub end and be removed without cutting welds, allowing quick inspection, cleaning, or system modification

• Flexible Installation – The flange rotates 360° around the stub end, making bolt-hole alignment simple and eliminating alignment issues common with weld neck flanges

• Corrosion Resistant – SS304 material provides excellent resistance to oxidation and various corrosive media, ensuring long service life

• Dimensional Accuracy – Manufactured per ASME B16.9 with strict tolerances, ensuring perfect compatibility with standard lap joint flanges

5. Product Functions

• Creates a flanged connection that allows for easy disassembly without cutting pipe welds

• Provides a smooth, continuous sealing surface that matches the lap joint flange face

• Accommodates thermal expansion and pipe movement without stressing the joint

• Enables use of lower-grade backing flanges while maintaining corrosion resistance at the seal face

6. Installation Instructions

1. Slide the lap joint flange over the pipe or stub end before welding

2. Butt weld the plain (beveled) end of the stub end to the pipeline using qualified welding procedures

3. Ensure the flared end (lap) is precisely aligned to the pipe terminus

4. Slide the lap joint flange over the stub end, seating it against the back of the flare

5. Align the flange bolt holes with the mating flange and bolt together

6. The gasket seals between the flared end and the mating flange face

Note: For Type A (Long Pattern) stub ends, the lap thickness shall not be less than the nominal wall thickness of the connecting pipe .

7. Precautions

• Ensure pipe schedule matches the stub end wall thickness for proper fit

• Verify that the stub end material is compatible with the service fluid and temperature

• Do not weld the lap joint flange directly to the pipe – the flange must remain free to rotate

• Use appropriate welding procedures (WPS qualified) for butt weld connections

• For high-pressure applications, confirm pressure rating matches system requirements

• Inspect the lap face for scratches or damage before installation to ensure proper sealing

8. Shipping & Delivery

9. Payment Terms

10. Packaging

Standard Export Packaging:

• Each stub end individually wrapped with anti-rust oil coating

• Packed in nylon bags or plastic wrap to prevent moisture

• Secured in wooden cases or pallets for sea-worthy transport

• Custom packaging available upon request

11. Returns, Exchanges & After-Sales

• Quality Guarantee – 100% inspection before shipment; all products conform to ASME B16.9 standards

• Return Policy – Returns accepted within 30 days for manufacturing defects (subject to inspection)

• Exchange – Free replacement for any non-conforming products confirmed by third-party inspection

• Sample Policy – Free samples available; buyer covers freight cost

• Technical Support – 24-hour response to all technical inquiries

• Custom Orders – Custom sizes, materials, and finishes available upon request