API 5L specification

Specification for seamless and welded steel line pipe manufactured according two products levels PSL1 / PSL2.

PROCESS OF MANUFACTURE – TYPES OF PIPE

Seamless pipe manufactured by hot working steel or if necessary by subsequently cold finishing the hot worked

Electric welded pipe having one longitudinal seam formed by electric resistance welding or electric induction welding without the addition of filler metal.

Welded pipe with one longitudinal seam formed by Laser welding process.

Longitudinal seam submerged arc welded pipe : pipe having arc longitudinal seam produced by automatic submerged arc welding process. At least one pass shall be made on the inside and at least one pass on the outside (pipe also known as SAW pipe).

Gas metal arc welded pipe having one longitudinal seam formed by continuous gas metal arc welding (MIG).

At least one pass shall be made on the inside and at least one pass on the outside.

Combination gas metal arc weld and submerged arc weld pipe having one longitudinal seam formed by the combination of continuous gas metal arc welding and automatic submerged arc welding. Double seam submerged-arc welded pipe having two longitudinal seams produced by the automatic submerged–arc welding process .

Double seam gas metal-arc welded pipe having two longitudinal seams produced by the gas metal-arc welding

Double seam combination gas-metal arc and submerged-arc welded pipe having two longitudinal seams produced by a combination of the submerged arc welding process and the gas metal-arc welding process.

Helical seam submerged-arc welded pipe having one helical seam produced by the automatic submerged-arc welding process (pipe also known as spiral weld pipe).

Pipe shall be either non-expanded or cold-expanded at the option of the manufacturer unless otherwise specified on the purchase order.

PROCESS OF MANUFACTURE :

1. PSL 1 is limited to sizes from 0.405 through 80 inches (10,3 to 2032 mm)
2. PSL 2 is limited to sizes from 4 1/2 to 80 inches (114,3 à 2032 mm)
3. Double seam pipe is limited to sizes 36 inches (914 mm) and larger
4. Helical seam pipe is limited to sizes 4 1/2 inches (114,3 mm) and larger.

CHEMICAL REQUIREMENTS (in %) FOR HEAT AND PRODUCT ANALYSES

PSL 1

PSL 2

a) For each reduction of 0.01 % below the specified maximum carbon content, an increase of 0.05 % above the specified maximum manganese content is permissible, up to a maximum of 1.50 % for grades X42 through X52, up to a maximum of 1.65 % for grades higher than X52 but less than X70, and up to 2.00 % for grades X70 and higher.

b) Columbium (niobium), vanadium, titanium, or combinations thereof may be used by agreement between the purchaser
and manufacturer.
c) Columbium (niobium), vanadium, titanium, or combinations thereof may be used at the discretion of the manufacturer.
d) The sum of the colombium (niobium), vanadium, and titanium contents shall not exceed 0.15 %.
e) Other chemical compositions may be furnished by agreement between purchaser and manufacturer, providing that the limits of footnote d and the tabular limits for phosphorus and sulfur are met.

TENSILE REQUIREMENTS

PSL 1

PSL 2

a) The minimum elongation in 2 in. (50.8 mm) shall be that determined by the following equation :

US Customary Unit Equation  \(e = 625,000 * {{A^{0.2}}\over U^{ 0.9}}\)

where
e = minimum elongation in 2 in. (50.8 mm) in percent rounded to the nearest percent.
A = cross-sectional area of the tensile test specimen in sq. in.
U = specified minimum ultimate tensile strength in psi.

b) Maximum yield strength for an intermediate grade shall be the maximum for the next higher listed grade.

c) All intermediate grades have a maximum ultimate tensile strength of 110,000 psi (758 MPa).

d) Maximum yield strength for grade B pipe in sizes subject to longitudinal testing is 72,000 psi (496 MPa).

e) For wall thickness greater than 0.984 in. (25.0 mm), the maximum yield strength shall be determined by agreement between the purchaser and the manufacturer.

TOLERANCES ON DIMENSIONS AND WEIGHTS

* In the case of pipe hydrostatically tested to pressures in excess of standard test pressures, other tolerances may be agreed upon between the manufacturer and purchaser.
** For pipes larger than 20 in. (508 mm) the average diameter of one end of pipe shall not differ by more than 3/32 in. (2.38 mm) from that of the other end.

***Particular tolerances for pipes with ≤75 D/t (see API).

Notes :
1 – For carloads composed of pipe from more than one order item, the carload tolerances are to be applied on an individual order item basis.
2 – The tolerance for order items applies to the overall quantity of pipe shipped for the order item.

Notes :
a – Nominal lengths of 20 ft (6 m) were formerly designated «single random lengths» and those of 40 ft (12 m) «double random lengths».
b – By agreement between the purchaser and the manufacturer, these tolerances shall apply to each carload.

HYDROSTATIC TESTS

Note : The hydrostatic test pressures given herein are mill-inspection test pressures ; they are not intended as a basic for design, and do not necessarily have any direct relationship to working pressures.

The test pressures are computed by the following formula and rounded to the nearest 10 psi (1 bar)

\(P = {2 S T \over D}\)

where

P = hydrostatic test pressure in psi (0.1 bar).
S = fiber stress in psi equal to a percentage of the specified minimum yield strength for the various sizes as shown below.
T = specified wall thickness in inches.
D = specified outside diameter in inches.

* Test pressures were limited to 2500 psi (172 bar) for 3 1/2 in. (88.9 mm) OD and smaller and to 2800 psi (193 bar) for sizes larger than 3 1/2 in. (88.9 mm) OD. Test pressures for other sizes are established arbitrarily.
** Test pressures for grades X42 through X80 were limited to 3000 psi (207 bar) to accomodate hydrostatic tester limitations.
*** Test pressures for grades X42 through X80 were limited to 7,260 psi (500 bar) for sizes < 16” (406.4 mm) and 3.630 psi (250 bar) for sizes ≥ 16” (406.4 mm)