What Is ISO 3183 Grade L290 Steel Pipe?
ISO 3183 is the international standard specifying technical delivery conditions for seamless and welded steel pipe (excluding stainless steel) used to convey and distribute flammable and non-flammable fluids in the petroleum and natural gas industries. Grade L290 (equivalent to API 5L X42) is one of the standard's covered grades, with a minimum yield strength of 290 MPa and defined limits for chemistry, mechanical properties and dimensions.
Covered Grades
The standard covers grades L175, L210, L245, L290, L320, L360, L390, L415, L450, L485, L555 and intermediate grades above L290, in product forms including threaded line pipe, plain-end pipe, standard-weight, extra-strong and double extra-strong pipe, plus bell-and-spigot pipe.
L290 Chemical Composition
| Condition | C (%) | Mn (%) | P (%) | S (%) |
|---|---|---|---|---|
| PSL1 seamless | 0.28 max | 1.30 max | 0.030 max | 0.030 max |
| PSL1 welded | 0.26 max | 1.30 max | 0.030 max | 0.030 max |
| PSL2 (L290N/Q/M) | 0.18–0.24 | 1.20–1.40 | 0.025 max | 0.015 max |
Mechanical Properties
| PSL | Grade | Yield (MPa) | Tensile (MPa) |
|---|---|---|---|
| PSL1 | L290 / X42 | 290 min | 415 min |
| PSL2 | L290N / X42N | 290–495 | 415–655 |
| PSL2 | L290Q / X42Q | 290–495 | 415–655 |
| PSL2 | L290M / X42M | 290–495 | 415–655 |
Acceptable Delivery Conditions
PSL1:
as-rolled, normalizing rolled, thermomechanical rolled or formed, normalized, normalized and tempered, or quenched and tempered (SMLS).
PSL2:
L290N (normalized), L290Q (quenched and tempered) or L290M (thermomechanically rolled), each with mandatory impact testing.
Applications
ISO 3183 L290 pipe is used for oil and gas gathering, gas distribution networks, water injection and utility pipelines where a 290 MPa strength level meets the design requirements, with PSL2 specified for higher-integrity duties.
Frequently Asked Questions
Is ISO 3183 L290 the same as API 5L X42?
Yes. L290 is the ISO metric designation and X42 the API designation for the same 290 MPa yield-strength tier.
What does PSL mean in ISO 3183?
PSL (Product Specification Level) defines the quality tier; PSL2 adds tighter chemistry, maximum strength limits and mandatory impact testing.
Does ISO 3183 cover threaded pipe?
Yes, including threaded and extra-heavy threaded line pipe, with thread requirements referenced to ISO 10422.
Can L290 be supplied seamless?
Yes, seamless and welded forms are both covered by the standard.
Which delivery condition gives the best toughness?
Normalized (N) and thermomechanically rolled (M) conditions offer the finest grain structure and best low-temperature toughness.
