Slip on Flange

Description

Slip-on flanges provide an economical and efficient connection method for low to medium pressure piping systems where frequent disassembly is not required. Characterized by their simple design with a bore slightly larger than the pipe’s outside diameter, these flanges slide over the pipe and are welded both internally and externally, creating a reliable connection that balances performance with installation efficiency.

Technical Specifications & Standards:

Material Grades:

• Carbon Steel: ASTM A105 (Forged), A350 LF2 (Low Temperature), A36 (Plate)

• Stainless Steel: ASTM A182 F304/304L, F316/316L, F321

• Alloy Steel: ASTM A182 F11, F22 (available upon request)

• Special Materials: Duplex, Nickel alloys (typically made from plate)

Design & Manufacturing Standards:

• Dimensional Standards: ASME B16.5 (1/2″-24″), MSS SP-44 (26″-60″)

• Pressure Classes: 150#, 300#, 600#, 900# (150# and 300# most common)

• Facing Types: Raised Face (RF), Flat Face (FF)

• Hub Configuration: Short hub design with controlled wall thickness

• Bore Dimensions: Slightly larger than pipe OD for easy slip-on fit

Critical Design Features:

• Double-Weld Construction: Fillet weld on hub exterior + optional internal weld

• Cost-Effective Design: Less material than weld neck, simpler machining

• Easy Alignment: Can be rotated for bolt hole positioning before final welding

• Reduced Weight: Approximately 1/3 lighter than equivalent weld neck flanges

• Standard Dimensions: Compatible with all standard bolt patterns and gaskets

Manufacturing Processes:

• Plate Cutting: CNC plasma/oxy-fuel from certified plate material

• Forging Option: ASTM A105 forged slip-ons for higher integrity

• Machining: CNC turning for facing and bore, drilling for bolt holes

• Quality Control: Dimensional verification to ASME tolerances

Performance Characteristics:

• Pressure Rating: Suitable for low to medium pressure applications

• Temperature Range: Typically -20°F to 750°F depending on material

• Fatigue Resistance: Lower than weld neck but adequate for static systems

• Installation Speed: Faster installation than weld neck flanges

• Cost Efficiency: Significant savings on material and installation labor

Quality Assurance Protocol:

• Material Certification: MTRs for all plate or forged materials

• Dimensional Verification: 100% inspection to ASME B16.5 tolerances

• Surface Inspection: Visual examination per MSS SP-55

• Welding Compatibility: Proper bevel preparation for fillet welding