Industrial Flange Standards Explained: ASME, EN, HG, JIS, GOST Comparison Guide

Understanding Global Flange Standards

Flange standards ensure interchangeability, safety, and performance across piping systems worldwide. As a leading flange manufacturer exporting globally, Songhai produces flanges compliant with all major international standards. This guide helps you navigate the differences and select the right standard for your project.

Major Flange Standards Overview

ASME B16.5 (USA/International)

The most widely recognized flange standard globally, covering pipe flanges and flanged fittings from NPS ½” to 24″.

Key Features:

  • Pressure Classes: 150, 300, 400, 600, 900, 1500, 2500
  • Flange Types: WN, SO, BL, SW, TH, LJ
  • Materials: Carbon steel, stainless steel, alloy steel, duplex
  • Temperature Range: -29°C to +595°C (depending on material)
  • Face Types: RF, FF, RTJ, M/F, T/G

Common Applications:

  • Oil & gas pipelines
  • Power generation
  • Chemical processing
  • International projects

Marking Requirements:

  • Manufacturer’s name or trademark
  • Material designation
  • Pressure class
  • Size (NPS)
  • Heat number or code

EN 1092-1 (Europe)

European standard for steel flanges and their products, widely used in EU and countries following European norms.

Key Features:

  • Pressure Ratings: PN 2.5, 6, 10, 16, 25, 40, 63, 100
  • Flange Types: Type 01-14 (covering all common types)
  • DN Range: DN 10 to DN 4000
  • Materials: P235GH to high-alloy steels

Type Designations:

Type Description
Type 01 Plate flange
Type 02 Loose plate flange
Type 04 Loose hubbed plate flange
Type 05 Blank flange
Type 11 Weld neck flange
Type 12 Hubbed slip-on flange
Type 13 Hubbed threaded flange
Type 21 Integral flange

Common Applications:

  • European industrial plants
  • Water treatment facilities
  • Food & beverage processing
  • HVAC systems

HG/T 20592-2009 (China)

Chinese chemical industry standard for steel pipe flanges, widely used in domestic and Asian markets.

Key Features:

  • Pressure Ratings: PN 2.5, 6, 10, 16, 25, 40, 63, 100, 160
  • Size Range: DN 10 to DN 2000
  • Series: Series A (international) and Series B (domestic)
  • Flange Types: PL, SO, WN, BL, SW, TH

Material Grades:

  • Carbon steel: Q235, 20#, 16Mn
  • Stainless steel: 06Cr19Ni10 (304), 06Cr17Ni12Mo2 (316)
  • Alloy steel: 15CrMo, 12Cr1MoV

Common Applications:

  • Chinese domestic projects
  • Chemical industry
  • Petrochemical refineries
  • Export to Asia/Middle East

JIS B2220 (Japan)

Japanese Industrial Standard for steel pipe flanges, commonly used in Japan and Southeast Asia.

Key Features:

  • Pressure Classes: 5K, 10K, 16K, 20K, 30K, 40K, 63K
  • Size Range: 10A to 1500A
  • Flange Types: So, Wn, Bl, Sw, Th

K Rating System:

  • 5K: Low pressure (similar to PN10)
  • 10K: Standard pressure (similar to PN16)
  • 16K-20K: Medium-high pressure
  • 30K-63K: High pressure applications

Common Applications:

  • Japanese industrial facilities
  • Shipbuilding
  • Power plants
  • Semiconductor manufacturing

GOST 33259-2015 (Russia/CIS)

Russian national standard for steel flanges, used in Russia and Commonwealth of Independent States.

Key Features:

  • Pressure Ratings: PN 0.1 to PN 200
  • Size Range: DN 10 to DN 2400
  • Flange Types: 1-13 (comprehensive coverage)
  • Execution: 1-7 (face types and configurations)

Material Designations:

  • Carbon steel: St20, St25, 09G2S
  • Stainless: 12X18H10T (321), 10X17H13M2T (316Ti)
  • Alloy: 15X5M, 12X1MF

Common Applications:

  • Russian oil & gas projects
  • CIS region infrastructure
  • Central heating systems
  • Heavy industry

Standard Comparison Table

Feature ASME B16.5 EN 1092-1 HG/T 20592 JIS B2220 GOST 33259
Region USA/Global Europe China Japan/Asia Russia/CIS
Pressure Class 150-2500 PN 2.5-100 PN 2.5-160 5K-63K PN 0.1-200
Size Range ½”-24″ DN 10-4000 DN 10-2000 10A-1500A DN 10-2400
Temperature -29°C to 595°C -60°C to 550°C -40°C to 550°C -29°C to 550°C -70°C to 650°C
Bolt Pattern Imperial Metric Metric Metric Metric

Pressure Class Equivalents

ASME Class EN PN HG PN JIS K GOST PN
150 PN 20 PN 20 10K PN 20
300 PN 50 PN 50 20K PN 50
600 PN 110 PN 110 40K PN 110
900 PN 150 PN 150 – PN 150
1500 PN 260 PN 260 – PN 260
2500 PN 420 PN 420 – PN 420

Face Type Standards

Raised Face (RF)

Most common face type across all standards. Raised surface concentrates gasket pressure.

  • ASME: 1.6mm (Class 150-300), 6.4mm (Class 400+)
  • EN: 2mm standard
  • HG: 2mm standard

Flat Face (FF)

Full face gasket contact, used with cast iron and low-pressure applications.

Ring Type Joint (RTJ)

Metal-to-metal seal for high-pressure/high-temperature service.

  • ASME: R, RX, BX series rings
  • EN: Type K per EN 1092-1

Tongue and Groove (T/G)

Self-aligning faces for critical applications.

Dimensional Differences

While standards aim for interchangeability, key differences exist:

Bolt Hole Diameter

  • ASME: Typically 1/8″ larger than bolt diameter
  • EN/HG/JIS/GOST: 2mm larger than bolt diameter

Flange Thickness

Varies between standards even for equivalent pressure ratings. Always verify dimensions when mixing standards.

Outside Diameter

ASME and EN flanges may have different OD for same nominal size, affecting bolt circle compatibility.

Material Specifications by Standard

ASME Material Grades

  • F304/F304L – Austenitic stainless
  • F316/F316L – Molybdenum austenitic
  • F321 – Titanium stabilized
  • F51 – Duplex 2205
  • F53 – Super duplex 2507

EN Material Numbers

  • 1.4301 – 304 equivalent
  • 1.4307 – 304L equivalent
  • 1.4401 – 316 equivalent
  • 1.4404 – 316L equivalent
  • 1.4462 – 2205 duplex

HG Material Grades

  • 06Cr19Ni10 – 304
  • 06Cr17Ni12Mo2 – 316
  • 022Cr19Ni10 – 304L
  • 022Cr17Ni12Mo2 – 316L

Quality Control Requirements

All standards require:

  • Chemical Analysis: Verification of material composition
  • Mechanical Testing: Tensile, yield, hardness
  • Dimensional Inspection: 100% verification
  • Marking: Permanent identification per standard
  • Documentation: MTC/certificate of conformity

Additional requirements for critical service:

  • Non-destructive testing (PT, MT, UT, RT)
  • Impact testing for low-temperature service
  • PMI (Positive Material Identification)
  • Third-party inspection

Songhai’s Multi-Standard Capability

As an ISO 9001:2008 certified manufacturer with 30+ years experience, Songhai produces flanges to all major standards:

  • ASME B16.5: Full range Class 150-2500
  • EN 1092-1: PN 2.5-100, all types
  • HG/T 20592-2009: Series A & B
  • JIS B2220: 5K-63K
  • GOST 33259-2015: PN 0.1-200
  • GB/T 9112-2010: Chinese national standard
  • NB/T 47021-2012: Pressure vessel flanges

Standard Selection Guide

Choose the right standard based on:

  1. Project Location: Follow local regulations and norms
  2. Existing Infrastructure: Match existing piping systems
  3. Client Requirements: Some EPC contractors specify standards
  4. Industry Practice: Oil & gas often uses ASME, Europe uses EN
  5. Availability: Consider local supplier capabilities

Contact Songhai for Standard-Specific Flanges

Need flanges to specific international standards? Songhai offers:

  • Free standard consultation
  • Cross-standard dimension verification
  • Complete certification packages
  • Fast delivery from stock or custom production
  • Competitive pricing FOB/CIF worldwide

Keywords: flange standards comparison, ASME B16.5, EN 1092-1, HG/T 20592, JIS B2220, GOST 33259, international flange standards, pressure class conversion, flange dimensions, stainless steel flanges manufacturer