API 5L welded steel pipe is one of the commonly used pipeline products in the oil, natural gas, and water transportation fields. Manufactured according to the API 5L standard set by the American Petroleum Institute, it features high strength, good toughness, and excellent corrosion resistance.

This type of steel pipe is mainly manufactured using the following welding processes:

ERW (Electric Resistance Welded Pipe)
LSAW (Straight Seam Submerged Arc Welded Pipe)
SSAW (Spiral Submerged Arc Welded Pipe)

Widely used in long-distance pipelines, urban pipe networks, structural engineering, and piling projects.

II. Introduction to API 5L Standard

The API 5L standard primarily regulates steel line pipes used for transportation, and is divided into two product levels:

Product Level	Characteristics	Applications
PSL1	Basic requirements	General pipeline projects
PSL2	More stringent chemical and mechanical requirements	High-pressure and highly corrosive environments

III. API 5L Material Grades

Common API 5L welded steel pipe material grades are as follows:

Grade	Yield Strength (MPa)	Tensile Strength (MPa)	Description
Grade A	≥ 245	≥ 415	Basic grade
Grade B	≥ 245	≥ 415	Most commonly used grade
X42	≥ 290	≥ 415	Medium-low strength pipeline
X52	≥ 360	≥ 460	Commonly used for oil and gas transmission
X60	≥ 415	≥ 520	Medium to high pressure pipelines
X65	≥ 450	≥ 535	Long-distance pipeline transmission
X70	≥ 485	≥ 570	High-pressure, high-strength applications

IV. API 5L Welded Steel Pipe Specification Range

1. ERW Welded Steel Pipe Specification Range (Electric Resistance Welded Pipe)

Outside Diameter (OD) (mm)	Outside Diameter (OD) (inch)	Wall Thickness (WT) (mm)	Common SCH	Single Length
21.3	1/2″	1.5 – 3.5	SCH 10 / 40 / 80	6m / 12m
26.7	3/4″	1.5 – 3.5	SCH 10 / 40 / 80	6m / 12m
33.4	1″	1.8 – 4.5	SCH 10 / 40 / 80	6m / 12m
42.2	1-1/4″	2.0 – 4.5	SCH 10 / 40 / 80	6m / 12m
48.3	1-1/2″	2.0 – 5.0	SCH 10 / 40 / 80	6m / 12m
60.3	2″	2.5 – 6.0	SCH 10 / 40 / 80	6m / 12m
73.0	2-1/2″	2.5 – 6.5	SCH 10 / 40 / 80	6m / 12m
88.9	3″	3.0 – 8.0	SCH 10 / 40 / 80	6m / 12m
114.3	4″	3.0 – 10.0	SCH 10 / 40 / 80 / 160	6m / 12m
141.3	5″	3.5 – 12.0	SCH 10 / 40 / 80 / 160	6m / 12m
168.3	6″	4.0 – 14.0	SCH 10 / 40 / 80 / 160	6m / 12m
219.1	8″	5.0 – 16.0	SCH 20 / 40 / 80 / 160	6m / 12m
273.0	10″	5.0 – 18.0	SCH 20 / 40 / 80 / 160	6m / 12m
323.9	12″	6.0 – 20.0	SCH 20 / 40 / 80 / 160	6m / 12m
355.6	14″	6.0 – 20.0	SCH 20 / 40 / 80 / 160	6m / 12m
406.4	16″	6.0 – 20.0	SCH 20 / 40 / 80 / 160	6m / 12m
457.0	18″	6.0 – 20.0	SCH 20 / 40 / 80	6m / 12m
508.0	20″	6.0 – 20.0	SCH 20 / 40 / 80	6m / 12m
559.0	22″	6.0 – 20.0	SCH 20 / 40 / 80	6m / 12m
610.0	24″	6.0 – 20.0	SCH 20 / 40 / 80	6m / 12m

2. Specifications of Longitudinal Submerged Arc Welded Steel Pipe (LSAW)

Outside Diameter (OD) (mm)	Outside Diameter (OD) (inch)	Wall Thickness (WT) (mm)	Single Length (m)	Standard
406	16″	6 – 50	6 – 12	API 5L / ASTM
457	18″	6 – 50	6 – 12	API 5L
508	20″	6 – 50	6 – 12	API 5L
559	22″	6 – 50	6 – 12	API 5L
610	24″	6 – 50	6 – 12	API 5L
660	26″	6 – 50	6 – 12	API 5L
711	28″	6 – 50	6 – 12	API 5L
762	30″	6 – 50	6 – 12	API 5L
813	32″	6 – 50	6 – 12	API 5L
864	34″	6 – 50	6 – 12	API 5L
914	36″	6 – 50	6 – 12	API 5L
965	38″	6 – 50	6 – 12	API 5L
1016	40″	6 – 50	6 – 12	API 5L
1067	42″	6 – 50	6 – 12	API 5L
1118	44″	6 – 50	6 – 12	API 5L
1168	46″	6 – 50	6 – 12	API 5L
1219	48″	6 – 50	6 – 12	API 5L
1320	52″	6 – 50	6 – 12	API 5L
1420	56″	6 – 50	6 – 12	API 5L
1524	60″	6 – 50	6 – 12	API 5L

3. Specifications of Spiral SAW Pipe

Outside Diameter (OD) (mm)	Outside Diameter (OD) (inch)	Wall Thickness (WT) (mm)	Single Length (m)	Production Features
219	8″	5 – 12	8 – 12	Small diameter
273	10″	5 – 14	8 – 12	Standard
325	12″	6 – 16	8 – 12	Standard
377	14″	6 – 16	8 – 12	Standard
426	16″	6 – 18	8 – 12	Standard
478	18″	6 – 18	8 – 12	Standard
529	20″	6 – 20	8 – 12	Standard
630	24″	6 – 20	8 – 12	Standard
720	28″	6 – 22	8 – 12	Large diameter
820	32″	6 – 22	8 – 12	Large diameter
920	36″	6 – 25	8 – 12	Large diameter
1020	40″	6 – 25	8 – 12	Large diameter
1220	48″	6 – 25	8 – 12	Large diameter
1420	56″	8 – 25	10 – 12	Extra-large diameter
1620	64″	8 – 25	10 – 12	Extra-large diameter
1820	72″	8 – 25	10 – 12	Extra-large diameter
2020	80″	8 – 25	10 – 12	Extra-large diameter
2220	88″	8 – 25	10 – 12	Extra-large diameter
2420	96″	8 – 25	10 – 12	Extra-large diameter
2620	104″	8 – 25	10 – 12	Extra-large diameter
2820	112″	8 – 25	10 – 12	Extra-large diameter
3020	120″	8 – 25	10 – 12	Maximum size

V. Supplementary Explanation

Project	Range / Specification
Standard	API 5L / ASTM A252 / GB/T 9711
Steel Grade	Grade B / X42 / X52 / X60 / X65 / X70
Anti-corrosion	3PE / FBE / Galvanized
Testing	UT / RT / Hydrostatic Testing