API 5L X56 Pipe Specification

API 5L X56 pipe is a medium grade pipe material in API 5L standard specifications. It’s yield strength minimum in 390 Mpa (56,600 psi), minimum tensile strength 490 Mpa.

API 5L X56 also called L390 Pipe named by yield strength 390 Mpa, it covers manufacturing types in seamless and welded (ERW, EFW, SAW) types. L390 pipe contains two product specification levels PSL1, PSL2. And for different services like sour, onshore, offshore services.

API 5L X56 Pipe Types

Ranges by Product Specification Level: PSL1, PSL2, Sour Services

API 5L X56 PSL1, for the pipes in common delivery condition of As Rolled.
API 5L X56N/M/Q, for PSL2 pipe with delivery condition of N, M, and Q.
API 5L X56NS/MS/QS, for PSL2 pipes with sour services.
API 5L X56NO/MO/QO, for offshore services.

Suffix Letter Means

R: As rolled
N: Normalizing rolled, Normalized formed, Normalized
Q: Tempered and quenched
M: Thermomechanical rolled or thermomechanical formed
S: Sour Service
O: Offshore

Manufacturing Types

Seamless: Covers hot rolled seamless and cold drawn seamless.
ERW: Electric Resistance Welded
LSAW: Longitudinal Sub-merged Arc Welding
SSAW: Spiral Sub-merged Arc Welding
HSAW / DSAW: Same with SSAW for spiral welded pipe

Features

API 5L X56 steel pipe has a minimum yield strength of 56,600 psi or 390 Mpa. The current X56 steel pipe are all controlled micro-alloyed carbon-manganese steels. The micro-alloys elements are mainly Nb, V and Ti, and the total content of micro-alloys does not exceed 0.15%. Therefore, the structure of the pipe is composed of acicular ferrite and bainite, and it generally has good welding performances.

Advantages:

a. High strength than Grade B and X42, X46, X52
b. High resistance to dynamic tearing
c. High low temperature impact toughness
d. Low ductile-brittle transition temperature
e. Acid service suitability, applicable to NACE
f. Economy and long lasting

Its excellent performance is due to the ultra-low carbon acicular ferrite structure, high density dislocations interact with fine precipitation phases.

API 5L Grade X56 Pipe Specification

API 5L Pipe Data Sheet, other grades specifications in API 5L.

API 5L X56 PSL1 Chemical and Mechanical Properties

API 5L X56 L390 Mechanical Properties

 

API 5L X56 PSL2 vs PSL1 Comparision

 

API 5L X56 (L390) PSL2 the maximum chemical content is different (lower) than PSL1; As well as the mechanical strength, is more strictly have a maximum limits.

API 5L X56 PSL2 Chemical Composition

API 5L X56 PSL2 Tensile Strength, Yield Strength

API 5L X56 Pipe Pressure Rating

API 5L grade X56 (L390 pipe) the yield strength minimum at 46400 Psi 320 Mpa, it’s the meaning that we call this grade in the API 5L X56 or L390. Tensile strength is 71100 Psi and 490 Mpa. X56 performance is better than Grade X42, X46, X52 and Grade B. It is A common used material grade in oil and gas industries.

Either x56 pipe in seamless or welded (ERW, LSAW), the pressure ratings, tensile strength and yield strength is the same

In case the working conditions require bigger pressure, we will have to increase the wall thickness of the steel pipes, or use higher grade in API 5L.

Test Requirements:

Bend Test: No cracks should be occur in any part of the sample or opening of weld.

Flattening test: Flattening test used to prove the pipe performances under deformation. It shall show the resistance to longitudinal cracking and circumferential cracking, including internal and external defects.

It shall be perfored to ERW pipes which diameters above 12.75 inch;
For pipes OD/WT > 10, there shall be no opening of the weld before the distance between the plates is less than 30% of the original OD.

Guided-bend test: Fracture completely; Reveal any cracks or ruptures in the weld metal longer than 3.2 mm, regardless of depth. Or reveal in parent metal, HAZ or fusion line longer than 3.2mm or deeper than 12.5% of wall thickness.

Hydrostatic Test: 100% hydrostatic test without leakage through the weld seam or the pipe body required. Connections or joints not need hydrostatic test if the pipe sections used were successfully tested.

CVN impact test: (Required PSL2 pipe, for seamless shall be tested with pipe body, for welded tests including pipe body, weld seam and heat-affected zon HAZ tests) Normally impact test temperature 0 ℃.

DWT test: (Required for PSL2 pipe)

Our Supply Ranges and Sizes

API SPECS 5L Gr. X56 or L390
Standard: API 5L, ISO 3183
Grade: X56 or L390 (Suffix letter N, Q, M, R)
Type seamless steel pipe: 21.3mm – 610mm, 1/2” – 24”
Welded ERW pipe: 21.3mm – 508mm, 1/2” – 20”
LSAW and SSAW pipe: 406mm – 2500mm, 16” – 100”
Pipe Thickness Schedule: SCH 10, SCH 20, SCH 30, SCH STD, SCH40, SCH60, SCH XS, SCH 80, SCH 100, SCH 120, SCH 140, SCH 160, SCH XXS of the standard thickness
Range of Length: SRL, DRL, 5 meter to 14 meter
Fixed Length: 5.8 Meter, 6.0 Meters (20FT), 11.8 Meters, 12.0 Meters (40FT)
Product Specification Level: PSL1, PSL2, Sour
Ends: Plain, Beveled Ends, Threaded Ends
Available Coating: Black Painting, Varnished, Anti-Rust Oil, FBE, 3PE/3LPE, 3PP, Galvanized, Concrete Weight Coating.

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