What Is ASTM A671 CC65 Class 40 Pipe?
ASTM A671 CC65 Class 40 pipe is an electric-fusion-welded (EFW) steel pipe produced from pressure-vessel-quality plate and completed with a filler-metal longitudinal seam. It belongs to ASTM A671/A671M, the specification for EFW pipe in atmospheric and lower-temperature service, and it is ordered where a cold-side line needs large diameter or a heavy wall that is impractical in seamless form.
The 65 in the grade is the minimum tensile strength level in ksi (448 MPa), higher than the 60 level and therefore useful where design pressure or support spacing favours a stronger plate. CC is the grade letter group that defines the heat-treatment and impact-testing route, and Class 40 is the plate material and test condition chosen from the ordering table of the specification.
In cold-side process service the pipe must keep its notch toughness at the design metal temperature, so the impact test temperature stated on the order is as important as the grade itself.
Grade, Class and Test Requirements
| Item | Requirement |
|---|---|
| Specification | ASTM A671/A671M, EFW pipe for atmospheric and lower temperatures |
| Grade | CC65, grade letter group CC with a 65 ksi (448 MPa) minimum tensile level |
| Class | Class 40, plate material and test condition from the A671 ordering table |
| Seam | Longitudinal seam welded with filler metal, single or double welded |
| Toughness | Charpy V-notch impact test at the ordered test temperature |
| Weld examination | Radiographic or ultrasonic examination of the full seam |
| Pressure test | Hydrostatic test per the specification unless otherwise ordered |
| Heat treatment | As-welded, stress-relieved or normalized as ordered |
The acceptance package combines chemical analysis of the plate, tensile results at the 65 ksi level, impact energy at the ordered temperature, the seam examination record and the hydrostatic test result. Where the pipe is to be welded on site, this data set is normally the basis for procedure qualification and for the client's receiving inspection.
Forming, Welding and Quality Control
Plate is cut to size and rolled to the ordered diameter; edges are prepared and the seam is welded with filler metal under a qualified procedure. Weld consumables are matched to the 65 ksi plate so that the seam reaches the strength required of the pipe body.
Radiographic or ultrasonic examination of the full seam documents weld soundness, and any repair is confined by the specification and re-examined to the same standard. Heat treatment follows where ordered, and the delivered condition is stated together with the test results so that the pipe can be matched to the design requirement.
Cold-Side Process Piping Applications
CC65 Class 40 pipe is used for cold-side process lines in gas treatment, liquefied gas handling, refrigeration and low-temperature sections of chemical and petrochemical plants, and for equipment connections and headers where long welded runs are preferred.
The 65 ksi plate level gives a useful margin over the basic carbon steel grades for pressure duty, while the welded format keeps diameter and wall options flexible and provides documented seam quality in place of field reliance on visual inspection.
Ordering, Inspection and Handling Notes
Quote specification, grade, class, size, wall thickness, length and impact test temperature together.
Match weld consumables and procedure qualification to the 65 ksi plate level.
Request full-seam weld examination records and hydrostatic test data with the shipment.
Check heat numbers against the marking, the test report and the plate certificate at receiving.
Protect beveled ends and store clear of mud, water and carbon steel offcuts.
FAQ
Q: What is the tensile level of CC65 pipe?
The number in the grade is the minimum tensile strength in ksi, so CC65 pipe is produced to a 65 ksi (448 MPa) minimum tensile level.
Q: How does Class 40 affect the product?
It selects the plate material and test condition from the ordering table of ASTM A671, and it is always quoted together with the grade, size and wall.
Q: Is the pipe impact tested?
Yes, where ordered for low-temperature service: Charpy V-notch testing is performed at the test temperature stated on the purchase order.
Q: What weld inspection applies?
The longitudinal seam is examined by radiographic or ultrasonic methods over its full length, and the finished pipe is hydrostatically tested.
Q: Where is this pipe normally used?
Cold-side process lines, gas treatment and liquefied gas systems, refrigeration circuits and low-temperature equipment connections.
