Threaded Flange Standard
Threaded Flange Standard
Threaded flange standards in different countries and industries differ in terms of dimensions, pressure ratings, material requirements, and so on. For example, American and European standards differ in details such as the form of sealing surface of flanges and the distribution of bolt holes. In the petrochemical field, the internationally recognized ASME B16.5 standard is often adopted due to its high requirements on the safety and stability of piping systems. In some regional small projects, local national standards or industry standards may be preferred to reduce costs and facilitate procurement.EATHU explains the many standards of threaded flanges for your purchasing choices.
（Ⅰ）Chemical Industry Standards
HG/T 20598 - 2009 "Steel Pipe Flanges (European System)":
Nominal Pressure: PN0.6, PN1.0, PN1.6, PN2.5, PN4.0.
Size Specifications: DN10 - DN150. For example, when DN10 is at PN0.6, the outer diameter of the flange is 75mm; when DN150 is at PN4.0, the outer diameter of the flange is 285mm.
Sealing Surface Forms: Raised Face (RF), Male and Female Face (MFM), Tongue and Groove Face (TG), etc. Different pressure levels correspond to different choices of sealing surface forms.
HG/T 20620 - 2009 "Steel Pipe Flanges (American System)":
Nominal Pressure: PN2.5 (Class150), PN5.0 (Class300).
Size Specifications: DN15 - DN150. For example, when DN15 is at PN2.5 (Class150), the outer diameter of the flange is 90mm; when DN150 is at PN5.0 (Class300), the outer diameter of the flange is 280mm.
Sealing Surface Forms: Raised Face (RF), Ring Joint Face (RJ), etc.
(Ⅱ) National Standards of China
GB/T 9114 - 2010 "Threaded Neck - Type Steel Pipe Flanges":
Nominal Pressure: PN5, PN10, PN16, PN25, PN40, PN63, PN100; as well as Class150, Class300, Class600, Class900, Class1500, Class2500.
Size Specifications: DN10 - DN600 (corresponding to different pressure levels, specific size values are specified. For example, when DN10 is at PN5, the outer diameter of the flange is 90mm, etc.).
Technical Requirements: There are strict regulations on the flange materials, machining accuracy, thread specifications, etc. The materials are usually carbon steel, alloy steel, etc., and the threads need to meet the corresponding accuracy grades.
Marking Example: Taking a threaded neck - type steel pipe flange with a nominal size of DN50 and a nominal pressure of PN16 as an example, the marking is: Flange GB/T 9114 - 2010 DN50 - PN16.
(III) Machinery Industry Standards
JB/T 2769 - 1992 "Threaded Flanges":
Nominal Pressure: PN16.0, PN22.0, PN25.0, PN32.0.
Size Specifications: DN3 - DN200. For example, when DN3 is at PN16.0, the outer diameter of the flange is 55mm; when DN200 is at PN25.0, the outer diameter of the flange is 375mm.
Material Requirements: High - quality carbon steel, alloy steel, etc. are mostly used to meet the requirements of high - pressure environments.
(IV) American Standards
ASME B16.5:
Pressure Ratings: Class150, Class300, Class400, Class600, Class900, Class1500, Class2500.
Size Specifications: 1/2" - 24". For example, when 1/2" is at Class150, the outer diameter of the flange is 89mm; when 24" is at Class2500, the outer diameter of the flange is 762mm.
Sealing Surface Forms: Raised Face (RF), Male and Female Face (MFM), Tongue and Groove Face (TG), Ring Joint Face (RJ), etc. There are various forms that can be selected according to different working conditions.
(V) Japanese Standards
JIS B2220:
Pressure Ratings: 5K, 10K, 16K, 20K.
Size Specifications: Corresponding to different nominal sizes. For example, when 10A (approximately equal to DN10) is at 5K, the outer diameter of the flange is 75mm; when 200A (approximately equal to DN200) is at 16K, the outer diameter of the flange is 340mm.
Sealing Surface Forms: Flat Face (FF), Raised Face (RF), etc.
(VI) German Standards
Taking DIN2527 as an example (one of many standards containing relevant content of threaded flanges):
Pressure Ratings: Covering multiple grades, such as PN6, PN10, PN16, etc.
Size Specifications: Different nominal sizes correspond to different outer diameters of the flange, the number and diameter of bolt holes, etc. For example, when DN50 is at PN10, the outer diameter of the flange is 165mm, the number of bolt holes is 4, and the diameter of the bolt holes is 18mm.
Sealing Surface Forms: Flat Face (FF), Raised Face (RF), etc.
(VII) British Standards
BS 4504, 4506:
Pressure Ratings: There are various pressure rating divisions corresponding to different working pressure ranges.
Size Specifications: The flange parameters for different nominal sizes are specified, such as the outer diameter of the flange, thickness, bolt hole distribution, etc.
Technical Requirements: There are detailed regulations on the chemical composition and mechanical properties of the materials, as well as the manufacturing process and inspection methods of the flanges.
When it comes to reliable threaded flange solutions, EATHU Company stands out. With years of experience in the industry, EATHU is committed to providing high - quality threaded flanges that strictly comply with various international and national standards. Our advanced manufacturing facilities and a team of skilled professionals ensure precision in every product. Whether you need flanges for a small - scale project or a large - scale industrial application, EATHU offers a wide range of products to meet your specific needs. We pride ourselves on our excellent customer service, providing timely technical support and after - sales service. Choose EATHU for all your threaded flange requirements and experience the difference of quality and reliability.
Threaded flange standards are important specifications in the field of industrial pipeline connections. Only by deeply understanding and reasonably applying these standards can practitioners ensure project quality and promote international cooperation and communication in their work.