API 5L X52 Pipe

API 5L X52 pipe is a medium-strength line pipe grade with a minimum yield strength of 359 MPa (52,000 psi) and a minimum tensile strength of 455 MPa (66,000 psi). Its ISO 3183 designation is L360, and it is one of the most widely used grades for cross-country oil and gas transmission pipelines.

Download API 5L X52 Pipe data sheet (PDF) One-page summary of the supply range, chemistry, mechanical properties and inspection documents on this page. The standard is the governing document.

Size range and specification

• Outside diameter 1/2 inch – 48 inch (12.7 – 1219 mm); seamless normally up to 24 inch
• Wall thickness 3.2 – 40 mm (SCH 10 – SCH 160, or by wall thickness)
• Length SRL 5.8 m, DRL 11.8 m, 20 FT, 40 FT, or random 6 – 18 m
• Ends Plain end, beveled end, threaded with coupling
• Surface treatment Black varnish, 3PE / 3LPE, FBE, 3PP, bare
• Delivery condition As-rolled (R), normalized (N), quenched and tempered (Q), thermomechanical (M)
• Manufacturing process Hot rolled seamless, ERW, LSAW, SSAW
• Delivery standard API 5L / ISO 3183, PSL1 or PSL2

How this grade is supplied

• Inspection Inspected by the producing mill’s own inspection department, which is independent of production, against the delivery standard above. Third-party inspection — SGS, BV or TUV, or an inspector you send yourself — can be arranged at the mill or before shipment; give us the dates and the scope at the order stage.
• Certificate A mill test certificate to EN 10204 3.1 showing the heat number, the chemical composition and the mechanical results is standard on every order. EN 10204 3.2, countersigned by the inspector you nominate, is available on request.
• Documents with the goods The mill test certificate and the packing list travel with the shipment, and the heat number is traceable from cast through to the finished product.
• Packing Sea-worthy export packing: bundled by size with end protection, corrosion protection on request, stencilled with the size, grade and heat number.
• MOQ One bundle or one truckload; mixed sizes within a bundle accepted.
• Lead time Counted from order confirmation, not from the enquiry. Stock sizes 5–10 days; mill run or non-stock 3–5 weeks. The delivery window is fixed on the quotation.
• How we supply Sourced through partner mills; the producing mill is named on the quotation.

API 5L X52 chemical composition, PSL2, wall thickness up to 25.0 mm (maximum, %)

PSL2 grades carry a delivery condition suffix. The three conditions commonly used for X52 are shown above. When carbon is 0.12% or below the CE(Pcm) limit of 0.25 applies instead of CE(IIW). PSL1 X52 has looser limits (P 0.030% max, S 0.030% max) and no carbon equivalent requirement.

Source: chemical composition requirements of API 5L / ISO 3183, Table 4 (PSL 1) and Table 5 (PSL 2). The standard is the governing document.

API 5L X52 mechanical properties

Elongation is calculated from the API 5L formula Af = C x A^0.2 / U^0.9, where A is the applicable tensile test cross-sectional area in mm2, U is the specified minimum tensile strength in MPa, and C is 1940 in metric units (625,000 in US customary units).

Source: tensile requirements of API 5L / ISO 3183, Table 7. The standard is the governing document.

What Is API 5L X52 Pipe?

API 5L X52 is a carbon steel line pipe grade with a minimum yield strength of 52,000 psi, equivalent to 359 MPa. ISO 3183 designates the same grade L360. It sits in the middle of the standard grade range, above Grade B and X42 and below X60 and X65. Because it offers a good combination of strength, toughness and weldability at a moderate price, X52 has become one of the default grades for oil, gas and water transmission lines and for many process piping applications.

PSL1 or PSL2 for X52?

PSL1 X52 specifies only minimum yield and tensile strength, with phosphorus and sulphur capped at 0.030% each and no carbon equivalent requirement. PSL2 X52 tightens phosphorus to 0.025% and sulphur to 0.015%, adds a carbon equivalent limit of 0.43 CE(IIW), caps the yield-to-tensile ratio at 0.93, and requires impact testing and non-destructive examination. Where the line carries sour or wet gas, or where low-temperature toughness matters, PSL2 is the appropriate choice. For lower-demand water and utility lines PSL1 is often sufficient and cheaper.

Where X52 Pipe Is Used

X52 is the workhorse grade for medium-pressure transmission. Typical uses include crude oil and natural gas trunk lines, water transmission mains, slurry pipelines, refinery and petrochemical process piping, and structural and piling applications where a defined yield strength matters. It is also widely used for pipe that will be hot-bent or field-bent, because its moderate strength and good ductility tolerate forming without the tighter process control that X65 or X70 demand.

X52, X60 or X65 – How to Choose

The higher the grade, the higher the allowable stress and therefore the thinner the wall can be for a given design pressure. But higher grades also cost more per tonne, require tighter welding procedures and, at the top of the range, give less tolerance for field conditions. X52 is usually the most economical choice when the line is not strength-limited or when wall thickness is set by handling and stability rather than by pressure. X60 and X65 become worthwhile when the design pressure is high enough that the saving in steel weight exceeds the higher price per tonne.

Sizes, Ends and Coatings

X52 is available seamless up to about 24 inch and welded (ERW, LSAW, SSAW) in larger sizes. Standard lengths are single random at 5.8 m and double random at 11.8 m, with 20 ft and 40 ft also common for export. Ends can be plain, beveled for welding, or threaded with coupling. External coatings include black varnish, three-layer polyethylene (3PE/3LPE), fusion bonded epoxy (FBE) and three-layer polypropylene (3PP) for higher operating temperatures. Internal flow coating and cement lining can be supplied for water lines.

PSL2 requirements that change the order

Source: API 5L / ISO 3183, Tables 5, 7, 18, 20 and the applicable non-destructive examination clauses. The standard is the governing document.

What to specify on the enquiry

• Standard and grade API 5L X52, PSL1 or PSL2, delivery condition R / N / Q / M
• Size Outside diameter, wall thickness, length and quantity
• Ends Plain, beveled or threaded with coupling
• Coating Bare, black varnish, 3PE / 3LPE, FBE, 3PP or internal lining
• Tests Charpy temperature and energy, NDT coverage, sour-service or HIC/SSC requirements if applicable
• Documents EN 10204 3.1 as standard, or 3.2 with a nominated inspection agency
• Destination port For FOB / CIF delivery terms and freight

Typical applications

• Oil and gas transmission pipelines
• Water transmission mains
• Slurry and mineral pipelines
• Refinery and process piping
• Structural and piling pipe

Standards covered

• API 5L
• ISO 3183

Frequently asked questions

Where to go next

• API 5L Seamless Steel Pipe – seamless line pipe to API 5L
• API 5L ERW Welded Steel Pipe – smaller diameter ERW line pipe
• API 5L SSAW Spiral Welded Steel Pipe – spiral welded pipe for large diameter mains
• API 5L X65 PSL2 Pipe – the high-strength line pipe grade in detail
• API 5L Grade B Pipe – the low-strength line pipe grade, PSL1 and PSL2
• Steel Pipe Weight Calculator – work out the weight of any size and wall thickness
• Pipeline Transmission – line pipe for gathering and transmission
• Get a Quote – send the grade, size, quantity and destination port