API 5L X42 Line Pipe Carbon Steel — Factory Direct Supplier | Huaxia-Steel
API 5L X42 line pipe is the entry-level high-strength line pipe specified by oil & gas operators for low-to-medium pressure gathering networks, distribution mains and water injection lines. With 42 ksi (290 MPa) minimum yield strength, X42 offers higher working pressure than ASTM A53 while remaining readily weldable with conventional field procedures. Huaxia Steel supplies seamless, ERW and LSAW X42 line pipe direct from our Chinese mills in sizes 1/2" to 26" (DN15–DN650), with PSL1 or PSL2 specification and EN 10204 Type 3.1 / 3.2 certification.
1. Product Overview
API 5L is the worldwide standard for line pipe used in the transportation of oil, gas, water and other fluids. X42 designates pipe with minimum 42,000 psi (290 MPa) yield strength. Compared to lower grades (A25, A, B, X46), X42 delivers stronger pipe at thinner walls, reducing tonnage, freight and welding time.
Huaxia Steel X42 line pipe is supplied in three manufacturing routes to match project requirements:
- Seamless (SMLS): hot-rolled or hot-extruded through a piercing mill, no weld seam. Default for high-pressure, sour service and thick-wall applications
- ERW (Electric Resistance Welded): formed from coil and welded longitudinally. Default for low-to-medium pressure distribution and gathering lines
- LSAW / DSAW (Longitudinal Submerged Arc Welded): formed from plate and double-submerged-arc welded. Default for large-diameter high-pressure transmission
2. Chemical Composition (PSL2)
| Element | API 5L X42 PSL2 (%) |
|---|---|
| Carbon (C), max | 0.24 |
| Manganese (Mn), max | 1.40 |
| Phosphorus (P), max | 0.025 |
| Sulfur (S), max | 0.015 |
| Vanadium (V), max | 0.06 |
| Niobium (Nb), max | 0.05 |
| Titanium (Ti), max | 0.04 |
| Carbon Equivalent (CE IIW), max | 0.43 |
| Carbon Equivalent (Pcm), max | 0.25 |
PSL2 imposes tighter chemistry than PSL1 to ensure weldability and uniform mechanical properties. The CE (IIW) limit of 0.43 means standard E6010 / E7010 / E7018 cellulosic and low-hydrogen stick electrodes are used without special preheating.
3. Mechanical Properties
| Property | API 5L X42 PSL2 |
|---|---|
| Yield strength, min | 42 ksi (290 MPa) |
| Tensile strength, min | 60 ksi (414 MPa) |
| Yield-to-tensile ratio, max | 0.93 |
| Elongation in 2 in. (50 mm), min | 25% |
| Charpy V-notch at 0°C, min avg | 27 J (20 ft·lbf) full size, project-dependent |
| Hardness, max | 22 HRC / 250 HV10 |
4. Standard Size Range and Schedule
X42 line pipe is supplied in standard schedule 20, 40, 80, STD, XS and XXS wall thicknesses, plus project-specific wall thicknesses. Common size ranges:
| Manufacturing Route | OD Range | Wall Thickness Range |
|---|---|---|
| Seamless | 1/2" – 26" (DN15 – DN650) | 2.0 – 40 mm |
| ERW | 1/2" – 24" (DN15 – DN600) | 2.0 – 20 mm |
| LSAW | 18" – 56" (DN450 – DN1400) | 6.0 – 40 mm |
5. End Finish and Connection Options
- Plain end (PE): square cut, suitable for slip-on flanges or couplings
- Beveled end (BE): 30° +/- 5° bevel per ASME B16.25, standard for field butt welding
- Threaded end (TE): API 5B threading for API 5L line pipe couplings
- Coupling stock: one end plain, one end upset for integral joint
6. Common Applications
- Oil & gas gathering networks connecting wellheads to processing facilities
- Low-to-medium pressure gas distribution mains (up to 4 MPa)
- Water injection lines for secondary oil recovery
- Firewater and cooling water pipelines in refineries and power plants
- Offshore platform piping (sour service requires NACE MR0175 compliance)
- Refinery and chemical plant cross-country process lines
- Compressed air and industrial gas distribution
7. Manufacturing Standards and Equivalents
- API 5L / 5L PSL1 & PSL2 (line pipe specification)
- ISO 3183 (line pipe, technical delivery conditions)
- ASME B31.3 (process piping)
- ASME B31.4 (liquid transportation systems)
- ASME B31.8 (gas transmission & distribution)
- NACE MR0175 / ISO 15156 (sour service — H2S-containing environments)
8. Sour Service and Low-Temperature Options
For sour service (H2S partial pressure > 0.0003 MPa), X42 pipe must comply with NACE MR0175 / ISO 15156. Huaxia Steel supplies sour-service X42 with the following options:
- Hardness limit 22 HRC / 250 HV10 maximum (PSL2 default)
- HIC test per NACE TM0284 (solution A or B, project dependent)
- SSC test per NACE TM0177 (Method A, four-point bent beam)
- Tight chemistry control on P and S (≤ 0.015% max)
- Calcium-treated steel for sulfide-inclusion shape control
For low-temperature service (down to −46°C / −50°F), consider upgrading to API 5L X42 PSL2 with supplementary requirement for Charpy testing at the required temperature, or specify ASTM A333 Grade 1/6 pipe instead.
9. Quality Assurance and Inspection
Each lot of X42 line pipe is supplied with EN 10204 Type 3.1 mill certificate including:
- Heat analysis + product analysis (chemistry)
- Tensile test (yield, tensile, elongation, Y/T ratio)
- Charpy V-notch test at specified temperature (PSL2)
- Hardness survey (per project requirement)
- Hydrostatic test to API 5L hydrostatic pressure (or NDE in lieu of hydrostatic)
- Dimensional and visual inspection
- Heat-treatment record (for normalised pipe)
- Non-destructive testing report (UT, RT, MT, eddy current as applicable)
Third-party witnessed inspection by SGS, BV, TUV, Intertek or ABS available on request. Witnessed inspection typically covers production monitoring, mechanical testing, hydrostatic test and pre-shipment verification.
10. Packaging and Shipping
Line pipe is bundled in standard hex bundles with steel straps, ends protected with plastic caps, wrapped in woven plastic or hessian, and loaded in 20’ / 40’ containers or break-bulk on flat racks for large diameters. Each bundle carries a tag with heat number, size, schedule, length and MTC number. Bundles are colour-coded for project traceability. Anti-rust coating or VCI film available for long-voyage destinations.
Standard lead time: 20–35 days for stocked grade and size, 40–70 days for project-specific orders. Standard Incoterms: FOB, CFR, CIF. Sample lot of 200–500 kg available for trial orders.
Need API 5L X42 PSL1 / PSL2 line pipe for a gathering, distribution or process piping project? Huaxia Steel supplies seamless, ERW and LSAW X42 pipe from 1/2" to 56", with NACE MR0175 sour service and low-temperature options. Email [email protected] with your OD, schedule, quantity, project specification, third-party inspection requirement and delivery port, and we will respond with a quotation within 24 hours.
