ISO 27509 Compact WN Flange Delivered to UK Client

Haihao Group has successfully completed the delivery of a compact weld neck (WN) flange to a customer in the United Kingdom. This project involved a high-pressure ISO 27509 compact flange, manufactured strictly in accordance with the client’s technical drawing and international standards, and intended for demanding offshore and oil & gas service conditions.

The supplied flange demonstrates Haihao Group’s capability in producing customized compact flanges with tight tolerances, special materials, and full compliance with sour service requirements.

Product Specification Overview

The delivered product is a compact WN flange designed for high-pressure pipeline systems where space-saving and sealing reliability are critical.

Key specifications:

• Type: Compact Weld Neck (WN) Flange

• Standard: ISO 27509:2020

• Nominal Size: DN100 (4″)

• Pressure Class: Class 2500

• Wall Thickness: SCH XXS (17.12 mm)

• Material: ASTM / ASME SA 182 F51 (Duplex Stainless Steel)

• Flange ID: 80 mm

• Tolerance: +0.0 / –0.6 mm

• Service Compliance: NACE MR0175 / ISO 15156 (latest edition)

Each dimension was carefully controlled to ensure precise fit-up and reliable sealing performance under high-pressure operation.

Advantages of ISO 27509 Compact Flanges

Compared with conventional ASME flanges, ISO 27509 compact WN flanges offer significant technical advantages, especially in offshore and subsea applications:

• Reduced size and weight, saving installation space
• High sealing efficiency under extreme pressure
• Lower bolt load requirements
• Improved performance in high-pressure and cyclic conditions

These features make Class 2500 compact flanges an ideal solution for oil & gas, offshore platforms, and high-integrity piping systems.

Duplex Stainless Steel SA 182 F51 for Sour Service

The flange material SA 182 F51 duplex stainless steel combines high mechanical strength with excellent resistance to pitting, crevice corrosion, and stress corrosion cracking.

For this UK project, the material was confirmed to fully meet the requirements of NACE MR0175 / ISO 15156, ensuring suitability for sour service environments containing H₂S.

Material verification included:

• Chemical composition analysis
• Mechanical property testing
• Dimensional inspection
• Traceability and certification review

Precision Manufacturing and Quality Control

Haihao Group manufactures compact weld neck flanges under a strict quality management system. For this order, particular attention was paid to:

• Machining accuracy of flange ID and sealing profile
• Compliance with ISO 27509 tolerances
• Surface finish and dimensional stability
• Final inspection prior to shipment

This ensures that every compact flange supplied is ready for direct installation without modification.

Trusted Compact Flange Manufacturer for Global Projects

With extensive experience in ISO 27509 compact flanges, duplex stainless steel flanges, and high-pressure WN flanges, Haihao Group supports clients across Europe, the Middle East, and Asia.

From standard specifications to fully customized designs, we provide reliable solutions for critical piping systems where safety and performance are essential.