In industrial piping systems, stainless steel flexible joints play a core role in absorbing vibrations, compensating for thermal expansion, and protecting critical equipment. However, to ensure precise installation and safe operation, selecting the correct flange connection standard is vital. This article provides a comprehensive overview of the common flange standards currently used in the fabrication and welding of flexible joints.
Why Choose the Right Flange Standard? The Importance of Proper Specification
Stainless steel flexible joints are typically constructed from high-strength, pressure-resistant materials such as SUS304 or SUS316. Depending on the stringent requirements of various industries—ranging from oil and gas to steam and wastewater—the flange fittings are engineered to provide superior sealing capabilities and withstand temperatures of up to 350°C.
Choosing an incorrect flange standard can result in misaligned bolt holes, leading to severe pressure leaks and system failure. Below are the most widely recognized global flange standards applied in the industry today:
BS 4504 Flange Standard
This is a well-established flange standard, most commonly utilized in the form of Raised Face Slip-on Flanges (Type 101 - RF).
- Size Range: Offers a diverse range of dimensions from DN10 to DN600 (equivalent to 3/8" – 24").
- Pressure Ratings: Designed to withstand flexible system pressures, including PN6, PN10, PN16, PN25, and PN40.
- Materials: Available in Carbon Steel or Stainless Steel.
JIS B2220 Flange Standard
The Japanese Industrial Standard (JIS) for flanges is highly favored across the Asian market. For expansion joints and corrugated metal hoses, the JIS B2220 Flat Face (FF) type is exceptionally widely applied.
- Size Range: Provides an extensive scale of sizes, catering to requirements from DN10 up to DN1500.
- Pressure Classes: Categorized into various load-bearing levels, such as 5K, 10K, 16K, 20K, 30K, 40K, and reaching up to 60K.
- Materials: Manufactured from high-grade Carbon Steel or Stainless Steel.
ANSI B16.5 Flange Standard
Developed by the American National Standards Institute (ANSI), this standard is a global benchmark. In the fabrication of flexible hoses, ANSI flanges are most commonly utilized in the Slip-On configuration.
- Size Range: Covers a broad spectrum from 1/2" to 24" (equivalent to DN10 – DN600).
- Pressure Ratings: Specifically engineered for systems requiring Class 150 and Class 300 ratings.
- Materials: Available in Carbon Steel or Stainless Steel.
DIN and EN 1092-1 Flange Standards
These two European standards are closely aligned and often used interchangeably. Notably, the EN 1092-1 (Type 01, FF) standard differs from the BS (British Standard) primarily in its flange thickness specifications.
DIN Standard System
- DIN System: Provides customized designs based on pressure requirements, such as DIN 2573 (PN6), DIN 2576 (PN10), DIN 2502 (PN16), DIN 2503 (PN25), and DIN 2545 (PN40).
- Standard Pressure Ratings: PN6, PN10, PN16, PN25, and PN40.
- Size Range: From 3/8" to 24" (equivalent to DN10 – DN600).
- Materials: High-quality Carbon Steel or Stainless Steel.
EN Standard System
The EN system features distinct classifications with higher load-bearing capacities, such as PN63 and PN100.
- Pressure Ratings: PN6, PN10, PN16, PN25, PN40, PN63, and PN100.
- Size Range: 3/8" – 24" (Equivalent to DN10 – DN600).
- Materials: Carbon Steel / Stainless Steel.
Sanitary Flange Standards (SMS or DIN)
Exclusively designed for environments demanding absolute hygiene, sanitary flanges feature a specialized groove for silicon gasket placement. The sealing system utilizes a heavy-duty clamp to compress two flange faces, enabling quick assembly and disassembly while withstanding temperatures up to 200°C.
- Materials: Stainless Steel 304, Stainless Steel 316.
- Gasket Materials: Silicon, EPDM, PTFE.
- Available Sizes: ø12.7 – ø324.
- Operating Temperature: -180°C – 280°C.
- Working Pressure: 16 bar.
KF Vacuum Flange Standard
- Configuration: The assembly consists of two symmetrical flanges, a centering ring with an O-ring gasket, and an external wing nut clamp.
- Standard Sizes: KF10, KF16, KF25, KF40, and KF50.
- Applications: Ideal for cleanroom environments, gas delivery systems in semiconductor manufacturing, food processing, and laboratory analytical equipment.
Comprehensive Piping Solutions at Vietnam Hydraulic Equipment (VHE)
The selection of a compatible flange design is the deciding factor in the integrity and performance of a flexible joint assembly. At Vietnam Hydraulic Equipment Joint Stock Company, our technical consultancy and fabrication processes are executed with absolute precision, ensuring maximum safety for your systems.
We maintain a robust inventory of standard flanges at our warehouses, including:
- Stainless Steel Slip-on Flange (BS PN16): DN15 (1/2”) – SKU: WSS-BS PN16-015
- Stainless Steel Slip-on Flange (BS PN16): DN20 (3/4”) – SKU: WSS-BS PN16-020
- Stainless Steel Slip-on Flange (BS PN16): DN25 (1”) – SKU: WSS-BS PN16-025
- Stainless Steel Slip-on Flange (JIS 10K): DN15 (1/2”) – SKU: WSS-JIS10K-015
- Stainless Steel Slip-on Flange (JIS 10K): DN20 (3/4”) – SKU: WSS-JIS10K-020
- Carbon Steel Slip-on Flange (BS PN16): DN15 (1/2”) – SKU: WCS-PN16-015
- Carbon Steel Slip-on Flange (JIS 10K): DN20 (3/4”) – SKU: WCS-10K-020
Contact Vina Hydraulic Equipment Joint Stock Company today for a detailed quotation and expert consultation on the most suitable flange standards for your piping infrastructure!
Contact Information:
- Technical Support & Inquiries: 0903 067 588
- Email Support: [email protected]
- Head Office: 31 D20 Street, Phuoc Long Ward, Ho Chi Minh City, Vietnam.
- HCMC Warehouse: Street No. 10, Song Than Industrial Park, Di An Ward, Ho Chi Minh City, Vietnam.
- Hanoi Warehouse: Km28, Highway 6A, Dong De Industrial Park, Phu Nghia Commune, Hanoi, Vietnam.
