Product	API Code	GB Code	meanings	Standard	Application
Pipeline steel	B	L245NB	API code:X-		Used in Longitudinal Seam Submerged-arc Welded Pipe for Oil and Gas transportation
		L245MB	Meaning of the pipeline	API5L or GB/T9711.2
	X42	L290NB	Value - the value of the yield
		L290MB	strength for the British (B-class
	X46	L360NB	pipeline does not include the value
	X52		of the yield)
	X56	L360MB	GB code:
			L-means Pipeline
	X60	L415MB
			Value - the yield strength
	X65	L450MB	N- normalizing or normalizing
			rolling
	X70	L485MB	M- thermomechanical treatment
			B- B-class steel pipe

U.S.Code	GB Code	Chemical Composition%
		C≤	Mn≤	P≤	S≤	other
B	L245NB	0.22	1.2	0.025	0.015	b,d
	L245MB
X42	L290NB	0.22	1.3	0.025	0.015	c,d
	L290MB
X46	L360NB	0.22	1.4	0.025	0.015	c,d
X52
X56	L360MB
X60	L415NB	0.22	1.4	0.025	0.015	c,d
	L415MB
X65	L450MB	0.22	1.45	0.025	0.015	c,d
X70	L485MB	0.22	1.65	0.025	0.025	c,d

U.S.Code	GB Code	Yield Point Mpa		Tensile Strength Mpa		Elongation %
		Min.	Max.	Min.	Max.	2in(50.8mm)
						Min.
B	L245NB    L245MB	241	448	414	758	A
X42	L290NB    L290MB	290	496	414	758	A
X46		317	524	434	758	A
X52	L360NB    L360MB	359	531	455	758	A
X56		386	544	490	758	A
X60	L415NB    L415MB	414	565	517	758	A
X65	L450MB	448	600	531	758	A
X70	L485MB	483	621	565	758	A

     Pipeline because of their uniqueness, it has its specific details. These requirements include the composition of the requirements, and the carbon equivalent crack sensitive index requirements, DWTT tear drop weight requirements of space, V-cut area and impact energy requirements of the Cold requirements of the hardness requirements of the banded structure, grain size, inclusion request And ultrasonic flaw detection, and other requirements that may be specific contracts, technology and technical agreements as well.