GNEE GROUP

What is API 5L pipe?

API 5L steel line pipe adopts different steel grades, which are Gr. B, X42, X46, X52, X56, X60, X65, X70, X80. Some manufacturers are capable of manufacturing steel grades up to X100 and X120. As steel line pipes’ grades go higher, they have stricter control on the carbon equivalent control and higher mechanical strength performance.

Moreover, in the same grade, seamless and welded API 5L pipes have different chemical compositions, namely, welded pipes have stricter requirements and lower amounts of carbon and sulfur.

In terms of different delivery conditions, there are also As-rolled, normalizing rolled, thermomechanical rolled, normalizing formed, normalized, normalized and tempered, quenched and tempered.

API 5L pipe Delivery Condition

Chemical Composition for PSL 1 pipe with t ≤ 0.984.”

Chemical Composition for PSL 2 pipe with t ≤ 0.984.”

Steel Grade	Mass fraction, % based on heat and product analyses																		Carbon Equiv a
	C		Si		Mn		P		S		V		Nb		Ti		Other		CE IIW		CE Pcm
	max b		max		max b		max		max		max		max		max				max		max
Seamless and Welded Pipe
BR	0.24		0.4		1.2		0.025		0.015		c		c		0.04		e,l		0.043		0.25
X42R	0.24		0.4		1.2		0.025		0.015		0.06		0.05		0.04		e,l		0.043		0.25
BN	0.24		0.4		1.2		0.025		0.015		c		c		0.04		e,l		0.043		0.25
X42N	0.24		0.4		1.2		0.025		0.015		0.06		0.05		0.04		e,l		0.043		0.25
X46N	0.24		0.4		1.4		0.025		0.015		0.07		0.05		0.04		d,e,l		0.043		0.25
X52N	0.24		0.45		1.4		0.025		0.015		0.1		0.05		0.04		d,e,l		0.043		0.25
X56N	0.24		0.45		1.4		0.025		0.015		0.10f		0.05		0.04		d,e,l		0.043		0.25
X60N	0.24f		0.45f		1.40f		0.025		0.015		0.10f		0.05f		0.04f		g,h,l		As agreed
BQ	0.18		0.45		1.4		0.025		0.015		0.05		0.05		0.04		e,l		0.043		0.25
X42Q	0.18		0.45		1.4		0.025		0.015		0.05		0.05		0.04		e,l		0.043		0.25
X46Q	0.18		0.45		1.4		0.025		0.015		0.05		0.05		0.04		e,l		0.043		0.25
X52Q	0.18		0.45		1.5		0.025		0.015		0.05		0.05		0.04		e,l		0.043		0.25
X56Q	0.18		0.45f		1.5		0.025		0.015		0.07		0.05		0.04		e,l		0.043		0.25
X60Q	0.18f		0.45f		1.70f		0.025		0.015		g		g		g		h,l		0.043		0.25
X65Q	0.18f		0.45f		1.70f		0.025		0.015		g		g		g		h,l		0.043		0.25
X70Q	0.18f		0.45f		1.80f		0.025		0.015		g		g		g		h,l		0.043		0.25
X80Q	0.18f		0.45f		1.90f		0.025		0.015		g		g		g		i,j		As agreed
X90Q	0.16f		0.45f		1.9		0.02		0.01		g		g		g		j,k		As agreed
X100Q	0.16f		0.45f		1.9		0.02		0.01		g		g		g		j,k		As agreed
Welded Pipe
BM		0.22		0.45		1.2		0.025		0.015		0.05		0.05		0.04		e,l		0.043	0.25
X42M		0.22		0.45		1.3		0.025		0.015		0.05		0.05		0.04		e,l		0.043	0.25
X46M		0.22		0.45		1.3		0.025		0.015		0.05		0.05		0.04		e,l		0.043	0.25
X52M		0.22		0.45		1.4		0.025		0.015		d		d		d		e,l		0.043	0.25
X56M		0.22		0.45f		1.4		0.025		0.015		d		d		d		e,l		0.043	0.25
X60M		0.12f		0.45f		1.60f		0.025		0.015		g		g		g		h,l		0.043	0.25
X65M		0.12f		0.45f		1.60f		0.025		0.015		g		g		g		h,l		0.043	0.25
X70M		0.12f		0.45f		1.70f		0.025		0.015		g		g		g		h,l		0.043	0.25
X80M		0.12f		0.45f		1.85f		0.025		0.015		g		g		g		i,j		.043f	0.25
X90M		0.1		0.55f		2.10f		0.02		0.01		g		g		g		i,j		–	0.25
X100M		0.1		0.55f		2.10f		0.02		0.01		g		g		g		i,j		–	0.25
a. SMLS t>0.787”, CE limits shall be as agreed. The CEIIW limits applied fi C > 0.12% and the CEPcm limits apply if C ≤ 0.12%, b. for each reduction of 0.01% below the specified max. concentration for carbon, and increase of 0.05% above the specified max. concentration for Mn is permissible, up to a max. of 1.65% for grades ≥ B, but ≤ = X52; up to a max. of 1.75% for grades > X52, but < X70; and up to a maximum of 2.00% for X70., c. Unless otherwise agreed Nb = V ≤ 0.06%, d. Nb = V = Ti ≤ 0.15%, e. Unless otherwise agreed, Cu ≤ 0.50%; Ni ≤ 0.30% Cr ≤ 0.30% and Mo ≤ 0.15%, f. Unless otherwise agreed, g. Unless otherwise agreed, Nb + V + Ti ≤ 0.15%, h. Unless otherwise agreed, Cu ≤ 0.50% Ni ≤ 0.50% Cr ≤ 0.50% and MO ≤ 0.50%, i. Unless otherwise agreed, Cu ≤ 0.50% Ni ≤ 1.00% Cr ≤ 0.50% and MO ≤ 0.50%, j. B ≤ 0.004%, k. Unless otherwise agreed, Cu ≤ 0.50% Ni ≤ 1.00% Cr ≤ 0.55% and MO ≤ 0.80%, l. for all PSL 2 pipe grades except those grades with footnotes j noted, the following applies. Unless otherwise agreed no intentional addition of B is permitted and residual B ≤ 0.001% .

API 5L Pipe Mechanical properties

Pipe Grade	Tensile Properties – Pipe Body of SMLS and Welded Pipes PSL 1			Seam of Welded Pipe
	Yield Strength a	Tensile Strength a	Elongation	Tensile Strength b
	Rt0,5 PSI Min	Rm PSI Min	(in 2in Af % min)	Rm PSI Min
A	30,500	48,600	c	48,600
B	35,500	60,200	c	60,200
X42	42,100	60,200	c	60,200
X46	46,400	63,100	c	63,100
X52	52,200	66,700	c	66,700
X56	56,600	71,100	c	71,100
X60	60,200	75,400	c	75,400
X65	65,300	77,500	c	77,500
X70	70,300	82,700	c	82,700
a. For intermediate grade, the difference between the specified minimum tensile strength and the specified minimum yield for the pipe body shall be as given for the next higher grade.
b. For the intermediate grades, the specified minimum tensile strength for the weld seam shall be the same as determined for the body using foot note a.
c. The specified minimum elongation, Af, expressed in percent and rounded to the nearest percent, shall be determined using the following equation:
Where C is 1 940 for calculation using Si units and 625 000 for calculation using USC units
Axc   is the applicable tensile test piece cross-sectional area, expressed in square millimeters (square inches) , as follows
– For circular cross-section test pieces, 130mm2 (0.20 in2) for 12.7 mm (0.500 in) and 8.9 mm (.350 in) diameter test pieces; and 65 mm2 (0.10 in2) for 6.4 mm (0.250in) diameter test pieces.
– For full-section test pieces, the lesser of a) 485 mm2 (0.75 in2) and b) the cross-sectional area of the test piece, derived using the specified outside diameter and the specified wall thickness of the pipe, rounded to the nearest 10 mm2 (0.10in2)
– For strip test pieces, the lesser of a) 485 mm2 (0.75 in2) and b) the cross-sectional area of the test piece, derived using the specified width of the test piece and the specified wall thickness of the pipe, rounded to the nearest 10 mm2 (0.10in2)
U is the specified minimum tensile strength, expressed in megapascals (pounds per square inch)

 

Pipe Grade	Tensile Properties – Pipe Body of SMLS and Welded Pipes PSL 2						Seam of Welded Pipe
	Yield Strength a		Tensile Strength a		Ratio a,c	Elongation	Tensile Strength d
	Rt0,5  PSI Min		Rm  PSI Min		R10,5IRm	(in 2in)	Rm (psi)
						Af %
	Minimum	Maximum	Minimum	Maximum	Maximum	Minimum	Minimum
BR, BN,BQ,BM	35,500	65,300	60,200	95,000	0.93	f	60,200
X42,X42R,X2Q,X42M	42,100	71,800	60,200	95,000	0.93	f	60,200
X46N,X46Q,X46M	46,400	76,100	63,100	95,000	0.93	f	63,100
X52N,X52Q,X52M	52,200	76,900	66,700	110,200	0.93	f	66,700
X56N,X56Q,X56M	56,600	79,000	71,100	110,200	0.93	f	71,100
X60N,X60Q,S60M	60,200	81,900	75,400	110,200	0.93	f	75,400
X65Q,X65M	65,300	87,000	77,600	110,200	0.93	f	76,600
X70Q,X65M	70,300	92,100	82,700	110,200	0.93	f	82,700
X80Q,X80M	80,.500	102,300	90,600	119,700	0.93	f	90,600
a. For intermediate grade, refer to the full API5L specification.
b. for grades > X90 refer to the full API5L specification.
c. This limit applies for pies with D> 12.750 in
d. For intermediate grades, the specified minimum tensile strength for the weld seam shall be the same value as was determined for the pipe body using foot a.
e. for pipe requiring longitudinal testing, the maximum yield strength shall be ≤ 71,800 psi
f. The specified minimum elongation, Af, expressed in percent and rounded to the nearest percent, shall be determined using the following equation:
Where C is 1 940 for calculation using Si units and 625 000 for calculation using USC units
Axc   is the applicable tensile test piece cross-sectional area, expressed in square millimeters (square inches) , as follows
– For circular cross-section test pieces, 130mm2 (0.20 in2) for 12.7 mm (0.500 in) and 8.9 mm (.350 in) diameter test pieces; and 65 mm2 (0.10 in2) for 6.4 mm (0.250in) diameter test pieces.
–  For full-section test pieces, the lesser of a) 485 mm2 (0.75 in2) and b) the cross-sectional area of the test piece, derived using the specified outside diameter and the specified wall thickness of the pipe, rounded to the nearest 10 mm2 (0.10in2)
–  For strip test pieces, the lesser of a) 485 mm2 (0.75 in2) and b) the cross-sectional area of the test piece, derived using the specified width of the test piece and the specified wall thickness of the pipe, rounded to the nearest 10 mm2 (0.10in2)
U is the specified minimum tensile strength, expressed in megapascals (pounds per square inch
g. Lower values fo R10,5IRm may be specified by agreement
h. for grades > x90 refer to the full API5L specification.