Flanges Standards

A flange standard lays down the dimensions, surface finish, facing type, marking, material and technical specifications for flanges.

ASME B16.5 flange

ASME B16.47 flange

• ASME B16.47 Series A Class 150 Blind flange
• ASME B16.47 Series A Class 300 Blind flange
• ASME B16.47 Series A Class 400 Blind flange
• ASME B16.47 Series A Class 600 Blind flange
• ASME B16.47 Series A Class 900 Blind flange
• ASME B16.47 Series A Class 150 Weld Neck flange
• ASME B16.47 Series A Class 300 Weld Neck flange
• ASME B16.47 Series A Class 400 Weld Neck flange
• ASME B16.47 Series A Class 600 Weld Neck flange
• ASME B16.47 Series A Class 900 Weld Neck flange
• ASME B16.47 Series B Class 150 Blind flange
• ASME B16.47 Series B Class 300 Blind flange
• ASME B16.47 Series B Class 400 Blind flange
• ASME B16.47 Series B Class 600 Blind flange
• ASME B16.47 Series B Class 900 Blind flange
• ASME B16.47 Series B Class 150 Weld Neck flange
• ASME B16.47 Series B Class 300 Weld Neck flange
• ASME B16.47 Series B Class 400 Weld Neck flange
• ASME B16.47 Series B Class 600 Weld Neck flange
• ASME B16.47 Series B Class 900 Weld Neck flange

ASME B16.36

• ASME B16.36 Class 300 Orifice flange
• ASME B16.36 Class 600 Orifice flange
• ASME B16.36 Class 900 Orifice flange
• ASME B16.36 Class 1500 Orifice flange
• ASME B16.36 Class 2500 Orifice flange
• ASME B16.36 Class 600 RTJ Orifice flange
• ASME B16.36 Class 900 RTJ Orifice flange
• ASME B16.36 Class 1500 RTJ Orifice flange
• ASME B16.36 Class 2500 RTJ Orifice flange

BS 3293

• BS 3293 Class 150 Slip On flange
• BS 3293 Class 300 Slip On flange
• BS 3293 Class 400 Slip On flange
• BS 3293 Class 600 Slip On flange
• BS 3293 Class 150 Weld Neck flange
• BS 3293 Class 300 Weld Neck flange
• BS 3293 Class 400 Weld Neck flange
• BS 3293 Class 600 Weld Neck flange

Weld neck flange Dimensions

• Class 150 weld neck flange
• Class 300 weld neck flange
• Class 400 weld neck flange
• Class 600 weld neck flange
• Class 900 weld neck flange
• Class 1500 weld neck flange
• Class 2500 weld neck flange

DIN Standards

Other standards

What is the flange standard?

Flanges are typical components used in many industrial applications to connect pipes with mechanical devices. A flange code standard specifies the dimensions, finish, markings, facing type, and material. It also decides any other technical specifications. Flange standards differ across geographical regions. In Europe, the EN 1092 series is popular. It includes the Din flange standard and gets employed by many national bodies. For example, you can use DIN EN 1092 and NF EN 1092. The numerical value represents the maximum applicable pressure at a reference temperature of 20 degrees Celsius. You can find definitions for cast iron, copper, aluminium, and steel. The ISO 7005 standard is also internationally accepted. It covers DIN and ASME flanges, specifying the DN and PN designations for the latter. A Sae flange designed by the Society of Automotive Engineers conforms to SAE J518 standards.

What is the difference between ASME and DIN?

The American National Standards Institute laid down ANSI specifications. An Asme flange, designed by the American Society of Mechanical Engineers, meets the process requirements of ANSI. It uses millimetres and inches. The ASME B16.5 specification includes sizes up to 24″. You can refer to ASME B16.47 for components over 24″. In contrast, the Deutsches Institut für Normung (German Institute for Standardization) designed DIN specifications. DIN uses sizes in millimetres only. Usually, DIN mandates stricter tolerance compared to ANSI. The two standards also differ in tolerance levels and diameter sizes. The above differences result in variations across many other areas, like the equipment required for processing, the weight of the manufacturing material, and overall production processes. ASME is also called an Asa flange and is the most commonly referred standard across industries, along with DIN.

What is the nominal size of the flange?

When you take measurements for a flange, the nominal size is critical. It refers to the bore size of the component. A European flange standard and specifics from America use the nominal pipe size or NPS. The bottom line is it should match the bore size of the pipe. Based on this metric, you can find the specifications for your requirement. Most standard charts by manufacturers cover the bolt diameter, the number of bolts, and the bolt length for a pressure class based on the NPS. So, this definition will help you adapt the dimensions to low-pressure applications if you use an Awwa flange designed by the American Water Works Association. You can also use the nominal pipe size to assess the outer diameter of the component and the thickness. For instance, an Api flange, which adheres to standards developed by the American Petroleum Institute, is available in sizes up to 24″. The NPS also helps you understand the weight of the weld neck.

How do I know my standard flange?

You can find your standard flange by referring to the manufacturer charts. For instance, a B16.5 flange can range from 1/2″ to 24″ in pressure classes 150 to 2500. Different flange types cater to multiple needs and operate at variable pressures and temperatures. For example, threaded ones are better for low pressures, but you should go for lap joint flanges if you need connections with stub ends. These charts indicate the flange size based on the nominal pipe size and the diameter of the bolt circle. You can assess the diameter of the bolt hole and the inner diameter of the pipe within 1/8″ if you cannot find the exact flange.

How do I check my ANSI standards?

The American Society of Mechanical Engineers (ASME) first developed ANSI, or the American National Standard, for flanges and fittings. These standards cover ratings for pressure and temperature, dimensions, materials, and tolerance levels. The document also covers testing techniques for an Ansi flange. Here, the class depicts the pressure and temperature, like Class 150, 300, and 2500. You can check the corresponding standard from the stamp printed on the flange. Or, you can count the bolt holes if the stamping is unclear. Next, you have to find the diameter of the bolt circle. Once you have these two metrics, you can find the specification in the charts. You can get a list of the standards on the official portal. You can search by the title or the standard number.

International Standards for Flanges

• US Standards: ASME B16.5, ASME B16.47, ASME B16.48, ASME B16.36, AWWA C-207, MSS SP 44, API 605, API 6A.
• DIN Standards: DIN 2527, DIN 2573, DIN 2576, DIN 2502, DIN 2503, DIN 2543, DIN 2544, DIN 2545, DIN 2630, DIN 2631, DIN 2632, DIN 2633, DIN 2634, DIN 2635, DIN 2636, DIN 2637, DIN 2638, DIN 2628, DIN 2629, DIN 2627, DIN 2641, DIN 2642, DIN 2652, DIN 2653, DIN 2655, DIN 2656, DIN 2673, DIN 2674, DIN 2675, DIN 2676, DIN 2558, DIN 2561, DIN 2565, DIN 2566, DIN 2567, DIN 2568, DIN 2569, DIN 28115, DIN 86029, DIN 86030.
• BS Standards: BS 4504, BS 10, BS 3293, BS EN 1092-1.
• Italian Standards: UNI 2276, UNI 2277, UNI 2278, UNI 6083, UNI 6084, UNI 2280, UNI 2281, UNI 2282, UNI 2283, UNI 2284, UNI 2253, UNI 2254, UNI 6091, UNI 6092, UNI 6093, UNI 6094, UNI 6095, UNI 6088, UNI 6089, UNI 6090.
• ISO Standards: ISO 9624, ISO 7005-1.
• Australian Standards: AS/NZS 4331.1, AS 4087, AS 2129 Table D, Table E.
• Norwegian Standards: NS 2545, NS 2546, NS 2547, NS 2525, NS 2526, NS 2527, NS 2529, NS 2537, NS 2538, NS 25239, NS 2542, NORSOK L-005.
• Other Standards: GOST 12820-80, GOST 12821-80, MSZ flange, NFE 29203, VSM 18695, VSM 18696, VSM 18697, VSM 18716, VSM 18718, VSM 18703, JIS B2220, KS B1503, KS D4308, KS D3578, KS B2332, KS B2333, KS B6216, SABS/ SANS 1123.

Flanges are an essential component in the joining of pipes, valves, and other equipment in various industries. There are several manufacturing standards for flanges, each of which specifies the dimensions, materials, and testing requirements for flanges. Some commonly used flange manufacturing standards include:

1. ASME/ANSI B16.5: This standard covers flanges with nominal sizes from 1/2 inch to 24 inches and includes ratings for pressure-temperature, materials, dimensions, and tolerances. It is widely used in the oil and gas, chemical, and power generation industries.
2. ASME B16.47: This standard covers flanges with nominal sizes from 26 inches to 60 inches and includes ratings for pressure-temperature, materials, dimensions, and tolerances. It is commonly used in pipeline applications.
3. ISO 7005: This standard covers flanges with nominal sizes from 10 mm to 4000 mm and includes ratings for pressure-temperature, materials, dimensions, and tolerances. It is widely used in international applications.
4. DIN: This standard covers flanges with nominal sizes from DN 10 to DN 4000 and includes ratings for pressure-temperature, materials, dimensions, and tolerances. It is widely used in Europe.
5. JIS: This standard covers flanges with nominal sizes from 5A to 40K and includes ratings for pressure-temperature, materials, dimensions, and tolerances. It is widely used in Asia.

These are just a few examples of the flange manufacturing standards that exist. Choosing the appropriate standard depends on the specific industry, application, and requirements of the flange.