Coverage of API SPECIFICATION 5L
This specification specifies requirements for the manufacture of two product specification levels (PSL 1 and PSL 2) of seamless and welded steel pipe for use in pipeline transportation systems in the petroleum and natural gas industries.
Pipes are used in different types of environment such as corrosive and non-corrosive. If pipes used in the severe corrosive environment required material that can withstand such process condition. If pipe used in a high-pressure condition required weld seam withstand such requires. On other hands for normal services, a standard quality level pipe will meet the purpose. That’s why there are two product levels. We can choose according to the condition which pipe used and be economical.
- Non-destructive inspection of a seamless pipe is mandatory for PSL2 pipe whereas for PLS1 pipe it is supplementary requirements.
- Repair of pipe body plate and skim by welding is not allowed in PSL2 pipes whereas it is allowed in PSL1 pipes.
- Weld repair without filler metal is not allowed in PSL2 pipes whereas it is allowed with purchaser’s permission in PSL1 pipes.
In short, PSL 1 pipes are standard quality pipe for normal services and PSL 2 pipes are higher quality pipe than PSL 1. PSL 1 is a loose standard quality for line pipe, whereas PSL 2 contains additional testing requirement, stricter chemical physicals, along with different ceiling limits of mechanical properties, and require Charpy impact testing conditions.
The pipe grade for PSL 1 pipe is identical to the steel grade (designated by a steel name) and shall be as given in Table 1. It consists of an alpha or alphanumeric designation that identifies the strength level of the pipe and is linked to the chemical composition of the steel. The designations for Grade A and Grade B do not contain any reference to the specified minimum yield strength; however, the numerical portion of other designations corresponds with the specified minimum yield strength in SI units or with the upward-rounded specified minimum yield strength, expressed in 1000 psi for USC units.
Steel Grade:
please note, grades (such as A, B or C) are assigned that indicate certain characteristics of the steel based on differences in its chemical makeup and mechanical properties.
Delivery Condition of API 5L Grade L245 (Grade B):
- As-rolled,
- normalizing rolled,
- thermomechanical rolled,
- thermomechanical formed,
- normalizing formed,
- normalized,
- normalized and tempered;
- if agreed, quenched and tempered for SMLS pipe only
Delivery Condition of API 5L Grade L290 (X42) and Grade L360 (X52)
- As-rolled,
- normalizing rolled,
- thermomechanical rolled,
- thermomechanical formed,
- normalizing formed,
- normalized,
- normalized and tempered or
- quenched and tempered
For PSL 1 pipe with t ≤ 25.0 mm (0.984 in.), the chemical composition for standard grades shall be as given in Table 4, and the chemical composition for intermediate grades shall be as agreed, but consistent with those given in Table 4.
Chemical Composition of API 5L Grade B – Seamless
- Maximum 0.28% C, 1.20% Mn, 0.03% P, 0.40% , 0.03%S
- Cu ≤ 0.50 %; Ni ≤ 0.50 %; Cr ≤ 0.50 % and Mo ≤ 0.15 %.
- For each reduction of 0.01 % below the specified maximum concentration for carbon, an increase of 0.05 % above the specified
- maximum concentration for Mn is permissible, up to a maximum of 1.65 % for grades ≥ L245 or B, but ≤ L360 or X52; up to a maximum of 1.75 % for grades > L360 or X52, but < L485 or X70; and up to a maximum of 2.00 % for Grade L485 or X70.
- Unless otherwise agreed, Nb + V ≤ 0.06 %.
- Nb + V + Ti ≤ 0.15 %.
Mechanical Properties
L245 or B
- Yield Strength, MPa (psi) = 245 (35,500)
- Tensile Strength, MPa (psi) = 415 (60,200)
L290 or X42
- Yield Strength, MPa (psi) = 290 (42,100)
- Tensile Strength, MPa (psi) = 415 (60,200)
L360 or X52
- Yield Strength, MPa (psi) = 360 (52,200)
- Tensile Strength, MPa (psi) = 460 (66,700)
disclaimer: for your work, please refer to the updated API 5L document issued by API
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