Reliability in Low-Temperature Applications: Haihao Group Dispatches Major Flange Order to Indonesia
Securing long-term joint integrity in critical energy and processing facilities requires exact alignment between material toughness, pressure ratings, and forging standards. Haihao Group has successfully completed fabrication, testing, and dispatch of a multi-specification shipment of forged flanges and specialized hub connections bound for an offshore/onshore pipeline expansion project in Indonesia.
This shipment consists of 42 high-pressure components engineered for both ambient and cryogenic or sub-zero operational environments. The core of the shipment features ASTM A350 LF2 low temperature steel flanges, alongside high-pressure stainless steel long weld neck fittings.
Technical Order Summary & Material Categorization
The order covers a broad spectrum of pipe diameters ranging from 2″ up to 24″, with pressure classes spanning Class 150, Class 300, Class 600, up to Class 1500, featuring heavy-wall schedules (SCH XS, SCH 60, SCH 80, SCH 120, SCH 160).
To ensure complete traceability and easy site installation, the shipment was categorized into three primary structural groups:
1. Low-Temperature Carbon Steel Weld Neck (WN) & Blind Flanges
High-yield carbon steel forged to ASTM A350 LF2 Class 1 provides exceptional Charpy V-notch impact toughness, making these components ideal for low-temperature fluid handling across Indonesian processing facilities.
| Item Description | Nominal Size | Pressure Class / Wall Thickness | Material Specification |
| Weld Neck Flange (WN) | 24″ | Class 150 / SCH 60 | ASTM A350 LF2 CL1 |
| Weld Neck Flange (WN) | 24″ | Class 300 / SCH 60 | ASTM A350 LF2 CL1 |
| Weld Neck Flange (WN) | 24″ | Class 150 / SCH XS | ASTM A350 LF2 CL1 |
| Weld Neck Flange (WN) | 16″ | Class 300 / SCH XS | ASTM A350 LF2 CL1 |
| Weld Neck Flange (WN) | 14″ | Class 300 / SCH XS | ASTM A350 LF2 CL1 |
| Weld Neck Flange (WN) | 12″ | Class 300 / SCH XS | ASTM A350 LF2 CL1 |
| Weld Neck Flange (WN) | 8″ | Class 300 / SCH 60 | ASTM A350 LF2 CL1 |
| Weld Neck Flange (WN) | 6″ | Class 300 / SCH 80 | ASTM A350 LF2 CL1 |
| Weld Neck Flange (WN) | 6″ | Class 300 / SCH 120 | ASTM A350 LF2 CL1 |
| Weld Neck Flange (WN) | 4″ | Class 300 / SCH 120 (×2) | ASTM A350 LF2 CL1 |
| Weld Neck Flange (WN) | 4″ | Class 150 / SCH 160 | ASTM A350 LF2 CL1 |
| Weld Neck Flange (WN) | 3″ | Class 300 / SCH 160 (×2) | ASTM A350 LF2 CL1 |
| Weld Neck Flange (WN) | 2″ | Class 300 / SCH 160 | ASTM A350 LF2 CL1 |
| Blind Flange | 24″ | Class 150 (×2) | ASTM A350 LF2 CL1 |
| Blind Flange | 24″ | Class 300 | ASTM A350 LF2 CL1 |
| Blind Flange | 3″ | Class 300 | ASTM A350 LF2 CL1 |
| Blind Flange | 2″ | Class 300 (×2) | ASTM A350 LF2 CL1 |
| Blind Flange | 2″ | Class 150 | ASTM A350 LF2 CL1 |
2. Specialized High-Integrity Forged Hubs & FVC Connectors
For high-vibration sections and heavy nozzle connections on pressure vessels, custom heavy-wall forged hubs and FVC-HUB connectors were supplied to meet specific project dimensions.
| Item Description | Nominal Size | Rating / Wall Thickness | Material Grade |
| Heavy Forged HUB | 24″ | 70 mm Thickness | ASTM A350 LF2 CL1 |
| Heavy Forged HUB | 10″ | 40 mm Thickness (×2) | ASTM A350 LF2 CL1 |
| Heavy Forged HUB | 8″ | 40 mm Thickness | ASTM A350 LF2 CL1 |
| FVC-HUB Connector | 2″ | Class 300 (×3) | ASTM A350 LF2 CL1 |
3. Long Weld Neck (LWN) Flanges (Carbon & Stainless Steel)
Long weld neck flanges act as extended nozzles for pressure vessels and boilers, eliminating the need for separate pipe stubs and extra weld inspection points.
| Item Description | Nominal Size | Pressure Rating | Material Grade |
| Long Weld Neck Flange | 2″ | Class 150 (×1) | ASTM A350 LF2 CL1 |
| Long Weld Neck Flange | 2″ | Class 300 (×9) | ASTM A350 LF2 CL1 |
| Long Weld Neck Flange | 2″ | Class 600 (×2) | ASTM A182 F316/316L Dual Grade |
| Long Weld Neck Flange | 2″ | Class 1500 (×1) | ASTM A182 F316/316L Dual Grade |
Engineering Superiority: Why Low-Temp Impact Toughness Matters
In demanding oil, gas, and chemical processing setups, elevated pressure alone is not the only stress factor—extreme thermal drops can cause conventional carbon steel to exhibit brittle transition behavior.
Impact Energy Compliance: Utilizing ASTM A350 LF2 low temperature steel flanges guarantees that each forging maintains minimum Charpy impact energy requirements down to -46°C (-50°F).
Seamless Grain Alignment: Through precision hot forging and normalized heat treatment, Haihao Group achieves uniform grain refinement, ensuring consistent yield strength across heavy-wall flange necks (such as SCH 160 and 70mm thick hubs).
Dual-Certified Stainless Components: The Class 600 and Class 1500 LWN flanges manufactured in ASTM A182 F316/316L dual grade provide superior intergranular corrosion resistance while maintaining low carbon limits for high-pressure service.
Comprehensive Quality Control & Export Packaging
Prior to export shipment to South East Asia, every flange in this order underwent strict Quality Assurance (QA) verification:
Dimensional Precision Inspection: Flange face dimensions, bolt hole alignments, and hub wall thicknesses were verified against ASME B16.5 and ASME B16.47 standards.
Non-Destructive Testing (NDT): Ultrasonic Testing (UT) was conducted on thick-wall hubs, and Magnetic Particle Testing (MT) was performed on weld ends.
Surface Protection & Marking: Beveled ends were protected with heavy-duty end covers, surfaces were treated with rust-preventative oil, and all pieces received clear hard-stamping matching Material Test Reports (MTRs according to EN 10204 3.1).
Partner with Haihao Group for International Piping Projects
As a certified global manufacturer holding ISO, API, ABS, BV, CE, and EAC certificates, Haihao Group continues to deliver customized flange, pipe, and fitting solutions to major infrastructure developers across Southeast Asia, the Middle East, and worldwide.
Planning a pipeline or refinery project in Indonesia or Southeast Asia?
Contact Haihao Group’s engineering support team today to receive instant pricing, technical drawings, and comprehensive project consultation.


