Published: September 10, 2026 | Category: Standard Guide · Procurement Tips
Introduction
Across European and global boiler, heat exchanger, pressure vessel and petrochemical process piping sectors, EN 10216 is the most widely applied harmonized European standard for seamless steel pipes for pressure purposes. Among all grades, P235GH and P265GH — the two dominant non-alloy high-temperature grades — deliver similar but distinctly graded performance. Incorrect grade selection directly impacts project cost and operational safety.
As a professional stockist of industrial steel pipes, SANONPIPE maintains a full inventory of EN 10216 series seamless pipes covering all non-alloy and alloy grades. This article breaks down the core differences between P235GH and P265GH, and outlines key procurement checkpoints to provide clear selection guidance for engineering and procurement teams.
Overview of EN 10216 Standard
EN 10216 Seamless steel tubes for pressure purposes is a unified European standard specifying technical delivery conditions for seamless pressure pipes across different temperature ranges. It is structured into several parts:
- EN 10216-1: Non-alloy steel tubes with specified room-temperature properties, TR1/TR2 quality levels, for general pressure applications
- EN 10216-2: Non-alloy and alloy steel tubes for high-temperature service, GH quality class, for boilers, heat exchangers and elevated-temperature applications
- EN 10216-3: Fine grain steel tubes for low-temperature service
- EN 10216-4: Alloy steel tubes
GH grades (high-temperature class) are engineered for continuous elevated-temperature service. They require killed steel melting and normalizing heat treatment, with guaranteed high-temperature strength and creep properties, making them the standard choice for boiler tubes, exchanger tubes and pressure vessel shells.
Core Grade Comparison: P235GH vs P265GH
Both P235GH and P265GH are non-alloy high-temperature grades under EN 10216-2. The numbers indicate minimum yield strength in MPa. The two grades present clear gradients in chemistry, performance and application.
1. Chemical Composition Comparison
| Element | P235GH Limit | P265GH Limit | Key Difference |
|---|---|---|---|
| Carbon (C) | ≤0.16% | ≤0.20% | Higher carbon in P265GH delivers higher strength but slightly reduced weldability |
| Silicon (Si) | ≤0.35% | ≤0.40% | Both are fully killed; slightly higher Si in P265GH improves high-temperature oxidation resistance |
| Manganese (Mn) | ≤1.20% | ≤1.40% | Higher Mn in P265GH boosts strength via solid solution strengthening |
| Phosphorus / Sulfur (P/S) | ≤0.025% / ≤0.010% | ≤0.025% / ≤0.010% | Tight residual limits in both grades ensure high-temperature toughness and temper resistance |
| Residuals (Cr+Cu+Mo+Ni) | ≤0.70% | ≤0.70% | Unified residual control for consistent material quality |
2. Mechanical Properties Comparison (Room Temperature, t ≤ 16 mm)
| Property | P235GH | P265GH | Impact on Application |
|---|---|---|---|
| Min. Yield Strength | 235 MPa | 265 MPa | P265GH delivers ~13% higher yield, enabling thinner wall design at equal pressure |
| Tensile Strength Range | 360 – 500 MPa | 410 – 570 MPa | P265GH has an overall upward-shifted strength band with larger safety margin |
| Min. Elongation | 25% | 23% | P235GH offers better ductility for cold bending, expanding and tube forming |
| Min. Charpy Impact at 0°C | 27 J | 27 J | Equal low-temperature toughness, both meet standard boiler impact requirements |
| Max. Continuous Service Temp | ~400°C | ~425°C | P265GH retains strength at ~25°C higher metal temperature |
3. Application Scenarios & Selection Guide
| Dimension | Prefer P235GH | Prefer P265GH |
|---|---|---|
| Operating Temperature | ≤400°C low-to-medium temperature boilers, low-pressure exchangers | 400–425°C medium-high temperature service, medium-pressure main steam lines |
| Pressure Level | Low-to-medium pressure systems, auxiliary piping | Medium-high pressure mains, pressure vessel shells and headers |
| Fabrication | Tube bundles requiring extensive cold bending, expanding or flaring | Mostly straight welded runs where strength is the priority |
| Cost Focus | General projects prioritizing cost efficiency | High-parameter projects prioritizing strength and safety margin |
| Typical Uses | Boiler water walls, economizer tubes, low-pressure heat exchanger bundles | Boiler superheater sections, main steam headers, petrochemical medium-pressure process piping |
Core selection rule: Choose P235GH for temperatures ≤400°C and high forming requirements; choose P265GH for higher pressure, higher temperature and primarily welded construction. The cost difference is approximately 5–8%, and should be evaluated together with wall thickness optimization.
Brief Introduction to Other Common Grades
Non-Alloy High-Temperature Grades
- P195GH: Entry-level high-temperature grade with 195 MPa yield strength. Excellent formability, used for low-pressure boiler auxiliary tubes and smoke tubes; lowest cost option.
- P355GH: High-strength non-alloy grade with 355 MPa yield strength. For heavy-wall pressure vessels and large-diameter boiler headers; upgraded alternative to P265GH.
Alloy High-Temperature Grades
- 16Mo3: Molybdenum-alloy steel with excellent hydrogen attack resistance and creep performance. Used in refinery hydroprocessing units and high-pressure boilers; max service ~500°C.
- 13CrMo4-5: 1.25Cr-0.5Mo chrome-moly steel, equivalent to ASTM P11. Common in medium-temperature hydroprocessing and sulfidic service.
- 10CrMo9-10: 2.25Cr-1Mo chrome-moly steel, equivalent to ASTM P22. Superior creep resistance; industry standard for power plant main steam lines.
Key Procurement Considerations
1. Specify Standard Part & Quality Class Clearly
Always state the full designation such as EN 10216-2 P235GH, not just the grade name. GH grades must be fully killed and normalized (+N). TR (room-temperature) grades must never be substituted for GH service.
2. Wall Thickness & Dimensional Tolerances
EN 10216 default wall tolerance is +12.5% / -10%. For high-precision projects, T2 tolerance (±10%) can be agreed. For large-diameter heavy-wall pipe, specify out-of-roundness requirements to avoid fit-up issues on site.
3. Inspection & Non-Destructive Testing
- Hydrostatic test is mandatory per standard, at pressure values specified or agreed.
- For boiler and pressure vessel service, ultrasonic testing (UT) is recommended to detect internal laminations and cracks.
- For heat exchanger tube bundles, eddy current testing (ET) is advised for surface and near-surface defect detection.
4. Quality Documentation & Traceability
Every batch must be supplied with EN 10204 3.1 Mill Test Certificates covering heat number, chemical composition, mechanical properties, heat treatment records and inspection reports. For EU projects or PED (Pressure Equipment Directive) applications, verify certificate traceability and validity.
5. Confirm Delivery Condition
GH grades are supplied in the normalized (+N) condition by default. For heavy-wall or high-strength requirements, normalized and tempered (+NT) can be agreed. Verify hardness range on receipt to ensure heat treatment was properly performed.
6. Verify High-Temperature Performance
For critical long-term high-temperature service, request high-temperature yield strength or stress rupture data from the mill — not just room-temperature properties — to confirm load-bearing capacity at design temperature.
Conclusion
P235GH and P265GH under EN 10216-2 form the ideal material pair for medium-temperature medium-pressure pressure systems: P235GH balances formability and economy as the workhorse for general exchanger and boiler tube bundles; P265GH delivers higher strength and temperature capability for medium-pressure mains and headers. Accurate grade matching and strict procurement quality control are essential to long-term safe operation of high-temperature pressure systems.
SANONPIPE stocks the full EN 10216 seamless pipe range, from non-alloy P195GH / P235GH / P265GH to chrome-moly alloy grades. With complete 3.1 documentation and customized NDT services, we deliver fast-response supply for boiler, petrochemical and pressure vessel industries.
For detailed stock lists, quotations or technical grade selection support, contact our sales team.
Post time: Sep-10-2026
