Plate Flange

A plate flange is a type of flange that is typically used to connect pipes or valves. These bolt holes are used to attach the flange to another flange or to the equipment. Plate flanges are often used in applications where welding is not possible or not desired, as they can be easily bolted together.

Plate flanges come in various sizes and materials to suit different applications and working conditions. They are commonly made from materials such as carbon steel, stainless steel, and alloy steel, depending on the requirements of the application.

Plate flanges are widely used in industries such as petrochemical, oil and gas, water treatment, and industrial processing. They provide a strong and secure connection between pipes or equipment, allowing for easy installation, maintenance, and repair.

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

Plate flanges come in various sizes to accommodate different piping requirements:

• Nominal Pipe Size (NPS): Typically ranges from ½ inch to 24 inches. Custom sizes can be fabricated for specific needs.
• Diameter and Thickness: The outside diameter (OD) and thickness of the flange depend on the pressure rating and the nominal size. Plate flanges are usually thinner compared to other types of flanges, which contributes to their cost-effectiveness.

Pressure Ratings

Plate flanges are generally used in low-pressure applications. The pressure ratings for plate flanges usually correspond to the following classes:

• Class 150 (PN 20)
• Class 300 (PN 50)
• Class 400 (PN 64)
• Class 600 (PN 100)

It is uncommon to find plate flanges used in higher pressure classes (e.g., Class 900, 1500, or 2500) due to their fabrication method and material properties.

Conclusion

When selecting a plate flange, it is important to consider the nominal pipe size, pressure class, material, and specific application requirements. Plate flanges are a cost-effective solution for low-pressure systems and offer the flexibility of easy fabrication and customization. Adherence to standards such as ASME/ANSI, DIN, or EN ensures compatibility and safety in piping systems.