Api Steel Casing Pipe
API steel casing pipe manufactured for structural integrity and corrosion resistance, designed to meet strict mechanical and dimensional requirements for oil, gas, and infrastructure applications.
Manufacturing
API steel casing pipes are produced from steel smelted in electric furnaces, treated with synthetic slag, and cast using continuous casting methods. This process ensures low phosphorus and sulfur content, resulting in chemically clean steel with high ductility, malleability, and corrosion resistance. Controlled steel grades and heat-treatment regimes enable the production of high-strength casing pipes suitable for low-temperature and corrosive environments.
Specifications
Steel casing pipes are manufactured with a minimum yield strength of 35,000 psi. Pipes are produced with smooth internal walls and precise straightness and roundness. Uniform wall thickness across the pipe body and joints helps prevent leakage and ensures structural reliability. Outside diameter, size, and wall thickness conform to ASTM Designation A252.
- Smooth, straight, and round pipe geometry
- Uniform wall thickness for casing and joints
- Compatibility with pull-on or wrap-around rubber casing end seals
- Exterior corrosion protection using water-based coating for shipping and storage
Quality Control
All welding operations are performed by qualified operators in accordance with ANSI/AWS D1.1 requirements. Mechanical testing includes reduced-section tensile testing for each production lot. Connections are visually inspected to ensure freedom from injurious defects prior to shipment.
- Qualified welding in compliance with ANSI/AWS D1.1
- Tensile strength verification per production lot
- No hydrostatic testing required
- Inspection and repair of any defective sections prior to shipment
Production Standards & Grades
| Standard | Grades / Steel Numbers |
|---|---|
| API 5L PSL 1 | L175 / A25, L210 / A, L245 / B, L290 / X42, L320 / X46, L360 / X52, L485 / X70 |
| API 5L PSL 2 | L245R / BR, L290N / X42N, L320N / X46N, L360N / X52N, L415 / X60N |
| API 5CT | PSL 1, PSL 2, PSL 3, H40, J55, K55, N80 |
| GB/T 9711.1 | L175, L210, L245, L290, L320, L360 |
| GB/T 9711.2 | L245NB, L290NB, L360NB |
| GB/T 9711.3 | L245NC, L290NC, L360NC |
Typical Applications
API steel casing pipes are widely used in oil and gas wells, foundation and piling systems, underground structures, and other applications requiring durable, straight, and corrosion-resistant steel casing solutions.