P265GH–TC2 Omega Shape Tube for Water Wall Panels
Omega Shape Tube (Ω Tube) is a special profiled seamless pressure tube, characterized by integrated side flanges with a cross-section like the Greek letter Omega (Ω). Multiple Omega tubes can be joined by continuous welding along their integrated side flanges to form integrated water-cooled panel walls.
P265GH–TC2 Omega Tube refers to Omega profiled tubes manufactured from seamless EN 10216-2 P265GH base tube under Test Category 2. Fully compliant with EU PED 2014/68/EU, it is the preferred water wall tube for metallurgical furnaces, waste heat boilers and vapor cooling systems.
Material Standard & TC2 Definition
P265GH (1.0425)
Standard: EN 10216-2 P265GH tube — Seamless steel tubes for pressure purposes with specified elevated temperature properties.
P Pressure service; 265 minimum yield strength ≥ 265 MPa; GH symbols for elevated temperature properties.
Chemical composition (ladle analysis, wt.%): C ≤0.20; Si ≤0.40; Mn 0.80–1.40; P ≤0.025; S ≤0.015; Al ≥0.020.
Mechanical properties: Tensile strength 410–570 MPa; minimum yield strength ≥265 MPa; minimum elongation ≥23% for longitudinal specimens. Its fine-grained microstructure delivers favourable resistance to creep and thermal fatigue, with minor performance degradation during long-term continuous service up to 400°C.
TC2 – Test Category 2 per EN 10216-2: TC1: ultrasonic testing only on tube ends; TC2: 100% full-length ultrasonic inspection (UT) on every tube, plus batch impact test and full dimensional verification. TC2 is mandatory for critical furnace water wall projects, required by third-party supervision such as Intertek and SGS.
Technical Advantages of Omega Profile
Assembly efficiency
Integrated straight flanges enable continuous welding into large water-cooled panels without additional flat bars or fins, reducing welding quantity and site construction period.
Fully sealed heating surface
Closely connected tube profiles eliminate flue gas bypass, improve waste heat recovery and protect outer casing from high-temperature radiation.
Structural rigidity
Ω geometry combines circular pressure-bearing capacity and planar support, offering better bending resistance against thermal deformation than bare round tube panels.
Stable fluid circulation
Smooth seamless circular bore minimizes scaling risk; cooling water removes furnace radiant heat for vapor cooling.
Convenient maintenance
Single tube replacement is achievable without dismantling the entire panel, cutting downtime loss.
Main Applications
- Flash furnaces, smelting furnaces & converters in non-ferrous metallurgy
- Water-cooled radiation flues of waste heat boilers, waste incineration boilers
- Water cooling frames for electric furnaces and submerged arc furnaces
- Industrial furnace EPC projects complying with PED regulation
Typical operating conditions: Feed water / saturated steam; working pressure 6–8 MPa; design temperature up to 345 ℃.
Manufacturing & Inspection Scope
- Raw material: EN 10216-2 seamless tube P265GH
- Forming: Precision hot or cold forming to create Omega flanges, controlled uniform wall thickness
- Heat treatment: Normalized to eliminate forming residual stress
- TC2 mandatory tests: Spectro chemical analysis; Tensile & Charpy impact test; 100% full-length ultrasonic testing EN 10228‑1; Full dimensional & contour inspection per drawing; Hydrostatic test upon request
- Documentation: EN 10204 Type 3.1 / Type 3.2 inspection certificates, NDT reports and heat treatment records available for customer inspection.
Key Selection Guidelines
- Clearly specify TC2 instead of TC1 for furnace water walls. Mix-up is not permitted.
- Omega tubes are non-standard customized products. Final dimension drawing including flange width, arc radius and nominal wall thickness must be confirmed in advance.
- Matching welding consumables for P265GH are required with proper preheating to avoid cold cracking.
- External high-temperature coating is optional for flue gas service with sulfur content.
Conclusion
P265GH–TC2 Omega Shape Tube integrates high-temperature pressure steel, full-length non-destructive testing and high-efficiency profiled geometry. Compared with conventional round tube water walls, it delivers superior tightness, heat transfer efficiency, faster erection and reliable long-term operation. It is an optimal technical solution for metallurgical and waste heat EPC projects.