API 5L GRB steel pipes are commonly used for oil and gas transportation under medium pressure and temperature conditions, offering good toughness and weldability. The GR.B grade typically utilizes iron components in steelmaking and alloying additives such as copper, chromium, nickel, and titanium to enhance corrosion resistance and thermal performance, ensuring long-term operation in harsh environments.
Chemical Composition API 5L Pipes Grade B in PSL1 Line Pipe
Chemical Composition API 5L Pipes Grade B in PSL2 Line Pipe
API 5L Grade B Line Pipe Physical Properties
API 5L GRB Seamless Pipe Manufacturing Process
Billet Preparation
Solid round steel billets (carbon steel/low-alloy steel) inspected and cut to length.
Piercing & Hot Rolling
Billet heated to 1200°C → Pierced into hollow shell → Continuously rolled for shaping.
Sizing & Cooling
Diameter calibrated by sizing mill → Water quenching or air cooling (material-dependent).
Finishing
Straightening → Eddy current/ultrasonic testing → End facing → Hydrostatic test → Anti-corrosion coating.
Core Feature: Weld-free structure, superior integrity for high-pressure/high-temperature applications (e.g., gas transmission mains).
API 5L GRB Welded Pipe Manufacturing Process
Coil Preparation
Steel strip uncoiled, leveled, and edge-trimmed.
Forming & Welding
ERW (Electric Resistance Welding): Strip formed into tube via rolls → High-frequency current fuses seam → Inner/outer bead removal.
SAW (Submerged Arc Welding): Pre-bent strip welded with dual-sided submerged arc (LSAW/spiral variants).
Post-Weld Treatment
Stress-relieving heat treatment → Sizing → Full-body ultrasonic/radiographic inspection.
Final Testing
Hydrostatic test → End machining → Coating (e.g., FBE/3PE).
Core Feature: High efficiency, lower cost, ideal for medium-low pressure systems (e.g., urban gas networks).
API 5L GRB Line Pipe Factory
