Guides
Engineering guides for 4130 pipe and fittings
Short, practical notes for the engineers and buyers who specify, order and inspect AISI 4130 parts for high-pressure oil and gas lines.
Start with AISI 4130 steel for the material, 4130 75K, 80K and L80 for how to call out strength on an order, and 4130 for sour service if the line may see hydrogen sulfide. The rest answer the questions that come up when a line is designed, ordered or inspected.
The steel
- AISI 4130 steelChemistry, equivalents (UNS G41300, 1.7218), properties by heat treatment and hardness.
- 4130 heat treatmentNormalizing, quench and temper, tempering for strength or hardness, and PWHT.
- 4130 75K, 80K and L80API 6A designations, L80 limits, hardness caps, and a callout template.
- 4130 vs 4140Chemistry, hardenability, strength, carbon equivalent and which to use where.
Service and ratings
- 4130 for sour serviceISO 15156-2 limits for 4130: 22 HRC, nickel, heat treatment, weld hardness and PWHT.
- Pressure ratingsWorking, cold working and test pressure; API 6A test pressures; B16.9 and union figure ratings.
- Hammer union figuresFIG 100 to 2002 ratings, sour gas versions, and why figures must never be mixed.
Line design
- Long sweep vs targeted teeDirection changes in choke and kill lines, targets and cushions, and the R/d of 10 rule.
- Choke and kill linesRigid, flexible and articulated lines; API 16C and API Std 53 rules; where 4130 fits.
Reference
Products
The guides explain the decisions; the product pages give our range: 4130 seamless pipe, butt-weld fittings, long sweep fittings and integral fittings, then flowline equipment, wellhead and manifold parts and the industrial range.