Steel Line Pipe VS Pipeline

Linepipe is a type of steel pipeline used for petroleum, natural gas, oil, and water transportation. Most of the steel pipelines are used in regions with severe natural conditions, such as polar regions, ice fields, deserts and oceans, etc. The lines are long and not easy to maintain, which requested strict quality requirements and specifications. The pipeline steel consists of seamless and welded steel tubes according to its manufacturing methods and made of high strength carbon steel., which can be laid in cold, high-sulfur areas or under the sea.

 

The advantages of steel linepipe

This linepipe typically has good mechanical properties such as wall thickness, high strength, high toughness and wear resistance, but also should be large diameter, good weldability, low-temperature resistance, corrosion resistance (CO2), seawater resistance and HIC, SSCC performance.

 

Steel pipeline not only requires high tensile strength and yield strength but also provides a buckling ratio of 0.85~0.93.

Harsh regional and climatic conditions require the pipeline steel to have a sufficiently low ductile and brittle transition temperature. The shear area of DWTT (drop hammer tear test) has become the main control index to prevent the brittle failure of the pipeline, and it is generally required that the fracture shear area of the sample should be ≥85% at the lowest operating temperature.

 

The standards for steel pipeline

Currently, the main technical standards for oil and gas conveying steel linepipes are API SPEC 5L, DNV-OS-F101, ISO 3183 and GB/T 9711, etc.

API 5L is a widely used specification developed by the main petroleum institute, which is only for steel pipe products, excluding the design, selection or installation of pipelines.

DNV-OS-F101 (subsea pipeline system) is a specification developed by Norske veritas specifically for subsea pipelines. It covers a wide range of contents, including pipeline design, materials, manufacturing, installation, testing, operation, maintenance, etc., which is usually stricter than API 5L.

ISO 3183 is the international organization for standardization developed on the oil and gas transport steel pipe delivery conditions, the standard is comprehensive, detailed but does not involve the pipeline design, installation, etc.

 

Linepipe steel grades

Process Specification Language
 
 

Pipe   grades

Steel   grades

PSL1

L175

A25

L175P

A25P

L210

A

L245

B

L290

X42

L320

X46

L360

X52

L390

X56

L415

X60

L450

X65

L485

X70

PSL2

L245R

BR

L290R

X42R

L245N

BN

L290N

X42N

L320N

X46N

L360N

X52N

L390N

X56N

L415N

X60N

L245Q

BQ

L290Q

X42Q

L320Q

X46Q

L360Q

X52Q

L390Q

X56Q

L415Q

X60Q

L450Q

X65Q

L485Q

X70Q

L555Q

X80Q

L625Q

X90Q

L690Q

X100M

L245M

BM

L290M

X42M

L320M

X46M

L360M

X52M

L390M

X56M

L415M

X60M

L450M

X65M

L485M

X70M

L555M

X80M

L625M

X90M

L690M

X100M

L830M

X120M

Note: the number after L represents the minimum yield strength (MPa); The number after X also indicates the minimum yield strength (1000psi); Delivery condition: R= rolling, N= normalizing (normalizing + tempering), Q= quenching + tempering, M= thermo-mechanical rolling; The suffix P indicates a specified amount of phosphorus.


We sell and distribute line pipe in a complete variety of sizes and grades. To learn more about our line pipe sales and distribution services or to get a quote for your pipe needs, please contact us now.