EN 10216-1 Seamless Steel Tubes for Pressure Purposes
Overview
EN 10216-1 is the European standard for seamless steel tubes for pressure purposes - Part 1: Non-alloy steel tubes with specified room temperature properties. It covers seamless carbon steel tubes designed for the conveyance of water, steam, gas, and other pressurized fluids at ambient temperature service.
Steel Grades & Designations
EN 10216-1 defines grades based on minimum yield strength:
| Grade Designation | Minimum Yield Strength (ReH), MPa | Minimum Tensile Strength (Rm), MPa | Comparable Standards |
|---|---|---|---|
| P195TR1/TR2 | 195 | 320-480 | ASTM A53 Gr. A, DIN 1629 St 35.0 |
| P235TR1/TR2 | 235 | 360-510 | ASTM A53 Gr. B, DIN 1629 St 35.4 |
| P265TR1/TR2 | 265 | 410-570 | - |
| P295TR1/TR2 | 295 | 440-600 | - |
Nomenclature:
P = Pressure purpose
Number = Minimum yield strength in MPa
TR1 = Suitable for service up to 300°C
TR2 = Suitable for service up to 450°C
TR designation refers to "temperature-rated" – tubes guaranteed to maintain specified mechanical properties at elevated temperatures.
Mechanical Properties (Room Temperature)
| Grade | Yield Strength (ReH) Min, MPa | Tensile Strength (Rm) Range, MPa | Min Elongation (A), % |
|---|---|---|---|
| P195TR1/TR2 | 195 | 320 - 480 | 25 |
| P235TR1/TR2 | 235 | 360 - 510 | 23 |
| P265TR1/TR2 | 265 | 410 - 570 | 22 |
| P295TR1/TR2 | 295 | 440 - 600 | 21 |
Note: Tensile strength is specified as a range, not just a minimum, ensuring optimal strength-ductility balance.
Chemical Composition (Maximum %)
| Grade | C | Si | Mn | P | S | Al total |
|---|---|---|---|---|---|---|
| P195TR1 | 0.13 | 0.35 | 0.70 | 0.025 | 0.020 | ≥0.020 |
| P195TR2 | 0.16 | 0.35 | 0.70 | 0.025 | 0.020 | ≥0.020 |
| P235TR1 | 0.16 | 0.35 | 0.80 | 0.025 | 0.020 | ≥0.020 |
| P235TR2 | 0.20 | 0.35 | 0.80 | 0.025 | 0.020 | ≥0.020 |
| P265TR1/TR2 | 0.20 | 0.35 | 1.20 | 0.025 | 0.020 | ≥0.020 |
| P295TR1/TR2 | 0.20 | 0.35 | 1.20 | 0.025 | 0.020 | ≥0.020 |
Key Features:
Fine grain steel: Aluminum killed for grain refinement
Low sulfur: ≤0.020% for better weldability and formability
Phosphorus control: ≤0.025% for improved toughness
Manufacturing Process
Seamless Tube Production:
Steel Making: Basic oxygen or electric arc furnace with secondary refining
Continuous Casting: Fine grain practice with controlled cooling
Hot Working: Mannesmann process (rotary piercing) or extrusion
Finishing: Sizing, straightening, cutting
Heat Treatment: Typically normalized (mandatory for certain applications)
Testing: Full compliance with standard requirements
Size Range:
Outside Diameter: 10.2 mm to 711 mm (≈ ⅜" to 28")
Wall Thickness: 1.0 mm to 80.0 mm
Length: Typically 6-12m; up to 18m available
Heat Treatment Requirements
| Condition | Symbol | Application |
|---|---|---|
| Normalized | +N | Standard delivery for most applications |
| Normalized & Tempered | +NT | For thicker walls or special requirements |
| As-rolled (hot finished) | +AR | By agreement, for certain sizes |
| Annealed | +A | For maximum ductility |
Note: For TR2 grades and tubes with wall thickness > 25 mm, normalization is generally mandatory.
Testing & Inspection Requirements
| Test | EN Standard Reference | Key Requirements |
|---|---|---|
| Hydrostatic Test | EN 10216-1 Clause 8 | Pressure = 20×S×tDD20×S×t (bar) S = 0.8 × ReH Duration ≥ 10 seconds |
| Tensile Test | EN ISO 6892-1 | Transverse specimens for D ≥ 40 mm |
| Flattening Test | EN ISO 8492 | For D ≤ 50 mm and t/D ≤ 0.1 |
| Bend Test | EN ISO 8491 | Alternative to flattening test |
| Nondestructive Test | EN 10246 series | Optional, by agreement (UT, ET) |
| Hardness Test | EN ISO 6506-1 | Optional, often specified |
| Visual Inspection | EN 10216-1 | 100% visual examination |
Dimensional Tolerances
| Parameter | Tolerance per EN 10216-1 |
|---|---|
| Outside Diameter (D) | D ≤ 101.6 mm: ±0.5 mm or ±0.75% (greater) 101.6 < D ≤ 406.4 mm: ±0.75% D > 406.4 mm: ±1.0% |
| Wall Thickness (t) | +15%, -10% of nominal |
| Eccentricity | ≤ 10% of nominal wall thickness |
| Length | Fixed length: +10 mm, 0 mm |
| Straightness | ≤ 0.15% of total length |
| Weight | ±10% of theoretical weight per single tube |
Applications
Primary Industries:
Power Generation: Feedwater lines, auxiliary steam systems
Oil & Gas: Process piping, utility lines
Chemical Industry: Process and service piping
Construction: Building service piping (HVAC, plumbing)
Industrial: Compressed air, steam, water systems
Typical Service Conditions:
Pressure: Moderate to high pressure systems
Temperature: Up to 450°C (for TR2 grades)
Media: Water, steam, air, non-corrosive gases/liquids
Environment: Primarily indoor/industrial applications
Comparison with Other Standards
| Parameter | EN 10216-1 P235TR2 | ASTM A106 Grade B | DIN 1629 St 35.4 |
|---|---|---|---|
| Yield Strength Min | 235 MPa | 240 MPa | 235 MPa |
| Tensile Range | 360-510 MPa | ≥415 MPa | 360-510 MPa |
| Carbon Max | 0.20% | 0.30% | 0.17% |
| Sulfur Max | 0.020% | 0.035% | 0.035% |
| Temperature Rating | Up to 450°C | Up to 400°C | Up to 300°C |
| Grain Refinement | Al-killed (mandatory) | Optional | Al-killed |
Advantages
Temperature Guarantee: TR grades provide guaranteed properties at elevated temperatures
Fine Grain Structure: Aluminum killing ensures consistent properties
Clean Steel: Low sulfur and phosphorus for better weldability
European Compliance: Harmonized standard for PED applications
Quality Assurance: Comprehensive testing requirements
Limitations
Temperature Limit: Maximum 450°C (for higher temps, use EN 10216-2)
Corrosion Resistance: Standard carbon steel - not for corrosive services
Low Temperature: Not suitable for sub-zero without additional testing
Cost: Typically higher than basic ASTM A53 pipe
Material Certification & Traceability
Required Documentation:
EN 10204 3.1 Certificate: Declaration of compliance with the order
EN 10204 3.2 Certificate: Specific inspection certificate (common)
Traceability: Full traceability to melt/heat number
Test Reports: Chemical analysis, mechanical tests, hydrostatic test
Mandatory Marking:
Manufacturer's name/trademark
EN 10216-1 designation
Grade (e.g., P235TR2)
Size (D × t)
Heat number
CE marking (for PED applications)
Heat treatment symbol (if applicable)
Fabrication & Welding
Welding Guidelines:
Preheat: Generally not required for t < 25 mm at ambient temperature
Filler Metals: AWS ER70S-6 or equivalent suitable
Post-Weld Heat Treatment: Optional for stress relief
Procedure Qualification: Per EN ISO 15614-1 or equivalent
Forming & Bending:
Cold Bending: Suitable for moderate radii (typically ≥ 3× D)
Hot Bending: Recommended for tight radii or thick walls
Springback: Account for in tooling design
Ordering Information
Essential Data:
Standard: EN 10216-1
Grade: PXXXTR1/TR2
Heat treatment condition: +N, +NT, etc.
Dimensions: D (mm) × t (mm) × L (mm or m)
Quantity: Number of pieces or total meters
Certification: EN 10204 3.1 or 3.2
Additional tests: NDT, hardness, etc.
End preparation: Plain, beveled, threaded
Sample Order:
text
Seamless tubes to EN 10216-1 Grade: P235TR2 Heat treatment: Normalized (+N) Dimensions: 168.3 × 7.1 × 8000 mm Quantity: 100 pieces Ends: Plain, cut square Certification: EN 10204 3.2 Additional: Hardness test report Marking: Per EN 10216-1 with heat number
Industry Usage & Market Position
European Market:
Standard Choice: For carbon steel pressure piping in EU
PED Compliance: Essential for CE marking of pressure equipment
Quality Perception: Considered premium quality
Price Position: Typically 10-20% above ASTM equivalents
Global Acceptance:
Widely accepted in international projects
Often specified in European-engineered facilities worldwide
Recognized by major oil companies and EPC contractors
Quality Assurance
Key Quality Parameters:
Grain Size: Fine grain structure (ASTM 5 or finer)
Surface Quality: Free of laps, seams, and excessive scale
Dimensional Consistency: Uniform wall thickness
Mechanical Properties: Within specified ranges
Traceability: Complete documentation chain
Common Inspection Methods:
Ultrasonic Testing: For internal defects and wall measurement
Eddy Current: For surface defects
Magnetic Particle: For surface-breaking defects
Positive Material Identification: For grade verification
Equivalent Standards Cross-Reference
| EN 10216-1 Grade | ASTM Equivalent | ISO Equivalent | JIS Equivalent |
|---|---|---|---|
| P235TR2 | A106 Gr. B | ISO 9329-2 P235 | JIS G3454 STPG 410 |
| P265TR2 | - | ISO 9329-2 P265 | - |
| P295TR2 | A106 Gr. C | - | - |
Technical Summary
EN 10216-1 represents the modern European standard for quality seamless carbon steel pressure tubes with guaranteed room and elevated temperature properties. Its key strengths are:
Temperature-Rated Grades: TR1 (300°C) and TR2 (450°C) with guaranteed high-temperature properties
Fine Grain Practice: Aluminum-killed steel for consistent properties
Clean Steel Chemistry: Low sulfur and phosphorus for better performance
Comprehensive Testing: Rigorous quality assurance requirements
PED Compliance: Essential for European pressure equipment market
Selection Guidelines:
For ambient temperature service: P235TR1 or P235TR2
For elevated temperature (≤450°C): P235TR2 or P265TR2
For higher strength: P265TR2 or P295TR2
For maximum availability: P235TR2 (most common grade)
When to Specify EN 10216-1:
Projects in Europe or governed by European standards
Applications requiring guaranteed elevated temperature properties
Critical services where quality assurance is paramount
When CE marking for PED compliance is required
In European-engineered facilities worldwide
The standard provides a reliable, well-documented material choice for pressure piping systems, with the quality controls and traceability expected in modern industrial applications.
*Note: For applications above 450°C or requiring alloy steels, consider EN 10216-2 (alloy steel tubes with specified elevated temperature properties).*
