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Auxiliary Lines For Drilling Risers

High performance pipe to secure your riser operations

Auxiliary lines are an integral part of offshore drilling riser joints and need to combine fatigue resistance, high strength and weldability. Choke and kill lines are pressure lines giving access to the well bore including when BOP is closed. Fluid can be pumped into the kill line and gas can be flowed out of the choke line. Mud boost lines are used as conduits for drilling fluid which is pumped into the riser just above the BOP stack to increase annular circulating velocities. In all cases, safety is paramount.

Customized tight tolerances
Tailored dimensions to reduce weight & optimize fatigue
Full range
Auxiliary lines are available in a full range of dimensions to meet all customer requirements
Cost effective
A competitive offer combining high quality and reliability
Performances & Applications


  • Excellent geometry (ovality & eccentricity)
  • Consistent mechanical properties
  • Excellent pipe strength
  • Good weldability


We offer high-strength low-alloy steel seamless pipe for choke & kill lines and boost lines with consistent mechanical properties and tight dimensional tolerances to ensure safe drilling operations. Our auxiliary lines can meet the most challenging environments including 20,000 psi BOP for deep offshore and HPHT applications.

Product Range
Product Range
  • Yield strength: 75-85 ksi
  • Grade: 4130
    Weldability: CE < 0.75
  • Comprehensive range: OD: 2 ₁⁄₂” to 7 ₁⁄₂” – WT: 0.5” to 1.5”
  • Tailor-made dimensions for specific requirements
  • Fixed length
  • Tolerances: down to +/- 6%
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