Threaded Flange

A Threaded Flange is a type of flange that has threads on its inner bore, allowing it to be screwed onto a threaded pipe or fitting. It is commonly used in piping systems where disassembly or maintenance may be required, as it provides an easy way to connect and disconnect components without welding. Threaded flanges are available in various sizes and pressure ratings to suit different applications, and they are often used in low-pressure and non-critical piping systems.

Material Grades

Stainless Steel: ASTM / ASME SA403 GR WP “S” / “W” / “WX” 304, 304L, 304H, 309, 310H, 316L, 316H, 317, 317L, 321, 321H, 904, 904L, 347, 347H.

Duplex Steel: ASTM / ASME SA815 UNS NO. S31803, S32205, S32550, S32750, S32760.

Carbon Steel: ASTM / ASME A234 WPB, WPC, ASTM / ASME A860 WHY42, WHY46, WHY52, WH60, WPHY65 & WPHY70

Alloy Steel : ASTM / ASME A234 WP1, WP5, WP9, WP11, WP 12, WP22, WP23, WP91

Sizes

Threaded flanges are typically available in a range of sizes to suit various piping requirements:

• Nominal Pipe Size (NPS): Generally ranges from ½ inch to 24 inches.
• Diameter and Thickness: The outside diameter (OD) and thickness of the flange vary according to the pressure class and nominal size. The dimensions follow the standard specifications provided by ASME/ANSI.

Pressure Ratings

Threaded flanges are designed to handle various pressure ratings, indicating the maximum pressure they can withstand at a given temperature. The common pressure classes include:

• Class 150 (PN 20)
• Class 300 (PN 50)
• Class 400 (PN 64)
• Class 600 (PN 100)
• Class 900 (PN 150)
• Class 1500 (PN 250)
• Class 2500 (PN 420)

Conclusion

When selecting a threaded flange, it’s important to consider the nominal pipe size, pressure class, and specific application requirements. Ensuring adherence to standards such as ASME/ANSI B16.5 is crucial for compatibility and safety. Threaded flanges offer ease of installation and maintenance, making them suitable for low-pressure, non-cyclic applications where welding is not feasible.