CTOD Testing as per API 1104 – Pipeline Weld and Fracture-Toughness Qualification
Qualitest Canada provides specialized CTOD (Crack Tip Opening Displacement) Testing services in full compliance with API Standard 1104: Welding of Pipelines and Related Facilities, including Annex A.3.4.3 Fracture-Toughness Testing.
Our ISO/IEC 17025–accredited laboratories and experienced fracture-mechanics engineers deliver precise CTOD data supporting pipeline weld procedure qualification, engineering critical assessments (ECA), and fitness-for-service evaluations.
We proudly serve clients across Canada — including Toronto, Halifax, Nisku, Calgary, Red Deer, Grande Prairie, Fort McMurray, Regina, Saskatoon, Vancouver, Surrey, Burnaby, Kamloops, Kelowna, Mississauga, Hamilton, Sarnia, Ottawa, London, Windsor, and Sudbury — as well as international pipeline operators and EPC firms.
Understanding CTOD Testing per API 1104
- CTOD testing measures the fracture-toughness and crack-propagation resistance of weld metal and heat-affected zones (HAZ) in pipeline steels.
- Under API 1104 Annex A.3.4.3, each welding procedure requires CTOD tests on both the weld metal and the HAZ, using at least three valid specimens per location — typically at the 12 o’clock, 3 o’clock (or 9 o’clock), and 6 o’clock positions on the test weld.
- Specimens are oriented parallel to the pipe axis (through-thickness crack direction) and tested at or below the minimum design temperature.
- API 1104 specifies that BS EN ISO 15653 criteria be applied for geometry and crack-front straightness, with valid δ-values (δc, δu, or δm) reported per ISO definitions
CTOD Specimen Orientation and Preparation
- Specimen geometry: Preferred B × 2B (single-edge notched bend SENB) configuration
- Orientation: Length parallel to pipe axis, crack tip through thickness
- Weld metal tests: Notch and fatigue crack tip located centrally in the weld
- HAZ tests: Pre-cracks aimed at coarse-grain HAZ within the central 70 % of thickness
- Minimum valid CTOD: 0.002 in (0.05 mm) for acceptance of procedure qualification
Applicable Codes and Standards
- API Standard 1104 – Welding of Pipelines and Related Facilities (Annex A.3.4.3 Fracture-Toughness Testing)
- BS EN ISO 15653 – Fracture-Toughness Testing of Welds (CTOD Method)
- ASTM E1820 / E1290 – J-Integral and CTOD Measurement Methods
- CSA Z662 Annex K – Correlative guidance for FAD/ECA assessment (using API 1104 formulation)
Why Choose Qualitest Canada
- ISO/IEC 17025–accredited facilities with sub-zero testing capability (–100 °C to +25 °C)
- Servo-hydraulic CTOD frames with high-resolution clip-on COD/CMOD gauges
- Expertise in API 1104, BS EN ISO 15653, and ASTM E1820 fracture-mechanics methods
- Comprehensive reporting including load–CMOD curves, fracture photographs, and δ value classification
Our CTOD Testing Capabilities
- Specimens: B × 2B or B × B SENB; extracted from 12 o’clock position
- Pre-crack: Fatigue extension ≥ 1.3 mm or ao/2; crack-front straightness per BS EN ISO 15653
- Temperature: At or below minimum design temperature
- Measurement: Synchronized load and CMOD acquisition
- Reporting: δc, δu, or δm values with fracture surface records and photographs
Benefits of CTOD Testing per API 1104
- Ensures fracture-toughness qualification of pipeline weld metal and HAZ
- Supports WPS/PQR approvals and fitness-for-purpose evaluations
- Provides data for ECA and FAD analysis of imperfections (A.5.1.2 – Options 1 & 2)
- Minimizes repairs by allowing toughness-based acceptance criteria
- Enhances reliability in low-temperature and high-stress pipeline service
Industries We Serve
- Pipeline Construction and Transmission
- Oil & Gas and Energy Infrastructure
- Offshore and Subsea Pipeline Projects
- Pressure-Piping and Process Facilities
- Engineering Design and Failure-Analysis Consultancies
Other Qualitest Services
- Charpy Impact & Fracture Toughness Testing (K_IC / J)
- WPS/PQR Qualification & Welder Certification (API 1104 / CSA Z662)
- Metallography & Hardness Mapping
- Chemical Analysis (OES, ICP-OES)
- NDT (UT, MT, PT, RT, AE, GPR)
- Concrete, Asphalt & Aggregate Testing
- Geotechnical & Environmental Investigations
Contact Us
📧 Email: admin@qualitests.com
- Ontario Office: 5, 760 Laurentian Dr, Burlington, ON L7N 3V6 | ☎ (647) 464-9480
- Alberta Office (Nisku): 702 – 23 Ave, Nisku, AB T9E 7Y6 | ☎ (780) 851-2020
- Alberta Office (Calgary): Calgary, AB T2G-3K6 | ☎ (587) 747-3787
- British Columbia Office: 112, 13085 115 Ave, Surrey, BC V3R 0C3 | ☎ (778) 381-7376