ASTM A672 GR C60 CLASE 12 Welded Pipe – Complete Guide
Overview
ASTM A672 is a standard specification for electric-fusion-welded steel pipes designed for high-pressure service at moderate and low temperatures. The Grade C60 Class 12 designation indicates a carbon steel pipe with a minimum yield strength of 60 ksi (415 MPa) and a wall thickness classification (Class 12). These pipes are commonly used in power plants, petrochemical industries, and gas transmission systems where high strength and weldability are required.
Key Features of ASTM A672 GR C60 CLASE 12
1. Material & Manufacturing
– Base Metal: Carbon steel with controlled chemical composition for weldability and strength.
– Welding Process: Electric fusion welding (EFW) with filler metal addition.
– Heat Treatment: Stress-relieved or normalized to enhance mechanical properties.
2. Pressure & Temperature Suitability
– Designed for moderate to high-pressure applications.
– Suitable for low-temperature service (impact testing may be required for sub-zero conditions).
3. Dimensions & Tolerances
– Wall Thickness (Class 12): Typically corresponds to Schedule 80 or heavier, depending on diameter.
– Sizes: Available in NPS 16″ (DN 400) and larger, with some manufacturers offering smaller diameters.
4. Standards Compliance
– ASTM A672: Standard specification for EFW pipes for high-pressure service.
– ASME B36.10M: Covers dimensions and weights.
– ASME B31.3: Process piping code for pressure applications.
Mechanical Properties (ASTM A672 GR C60)
| Property | Value |
|—————————-|——————————-|
| Tensile Strength (Rm) | ≥ 75 ksi (515 MPa) |
| Yield Strength (Rp0.2) | ≥ 60 ksi (415 MPa) |
| Elongation (A5) | ≥ 20% |
| Impact Test (if required) | Min. 20 ft-lb @ -50°F (-45°C) |
Chemical Composition (Typical)
| Element | Composition (%) |
|————–|———————|
| Carbon (C) | ≤ 0.20 |
| Manganese (Mn)* | 0.90–1.50 |
| Phosphorus (P) | ≤ 0.025 |
| Sulfur (S) | ≤ 0.025 |
| Silicon (Si) | 0.15–0.40 |
Applications
– Power Plants: High-pressure steam and water lines.
– Oil & Gas: Gas transmission pipelines, refinery piping.
– Petrochemical: Process piping for corrosive and high-pressure fluids.
– Cryogenic Services: When impact-tested, suitable for low-temperature use.
Testing & Inspection Requirements
1. Hydrostatic Testing – Mandatory (test pressure calculated per ASTM A672).
2. Non-Destructive Testing (NDT) – Radiography (RT) or ultrasonic testing (UT) for weld integrity.
3. Mechanical Testing – Tensile, bend, and impact tests (if specified).
4. Visual & Dimensional Inspection – Ensures compliance with tolerances.
Comparison with Similar Pipes
| Parameter | A672 GR C60 CL1 | API 5L X60 | A106 GR B |
|———————-|———————-|—————-|—————|
| Standard | ASTM A672 | API 5L | ASTM A106 |
| Process | EFW | Seamless/Welded | Seamless |
| Yield Strength | 60 ksi (415 MPa) | 60 ksi (415 MPa)| 35 ksi (240 MPa)|
| Primary Use | High-pressure pipes | Oil/Gas pipelines | High-temp steam |
Advantages of ASTM A672 GR C60 CLASE 12 Pipes
✔ High Strength – Suitable for demanding pressure applications.
✔ Weldability – Electric fusion welding ensures strong joints.
✔ Cost-Effective – More economical than seamless pipes for large diameters.
✔ Customizable – Available in various lengths, diameters, and wall thicknesses.
Ordering & Fabrication Notes
– Specify heat treatment condition (stress-relieved/normalized).
– If used in low-temperature service, require **impact testing.
– Galvanizing or coating can be applied for corrosion resistance.
ASTM A672 GR C60 CLASE 12 welded pipes are a high-strength, cost-effective solution for high-pressure and low-temperature applications in power, oil & gas, and chemical industries. Their electric-fusion-welded construction ensures reliability, while Class 12 thickness provides durability. When ordering, ensure compliance with ASTM A672 standards and specify any additional testing or coatings required for your application.
