Standard: API Spec 5L
API Spec 5L specifies requirements for the manufacture of two product specification levels (PSL 1 and PSL 2) of seamless pipe and welded steel pipes. This standard covers the steel pipes made from different manufacturing process like seamless steel pipe, Electric Resistance Welded (ERW) steel pipe, Longitudinal Seam Submerged Arc Welding (LSAW) pipe and Spiral Submerged-Arc welding (SSAW) pipes.
Application of API 5L Grade X70 LSAW Steel Pipe:
API 5L Grade X70 LSAW Steel Pipe is used in oil and gas transportation especially in deep sea where the environment is complicated and harsh.
Manufacturing Process of API 5L Grade X70 LSAW Steel Pipe:
API 5L Grade X70 LSAW Steel Pipe is manufactured by forming the X70 steel plates into a round shape then welding the seam through automatically arc welding process. In the production of API 5L X70 LSAW Steel Pipe, plates of grade X70 are formed by the molding machine into round shape then welded through double-sided submerged arc welding.
Details of API 5L Grade X70 LSAW Steel Pipe:
Manufacture:Longitudinally Submerged Arc Welding
Size: O.D.: 406～1422mm W.T.: 8～60mm
Length: 3-12M or specified length as required.
Ends: Plain End, Beveled End, Grooved
Chemical Composition of API 5L Grade X70 LSAW Steel Pipe:
Grade and Chemical Composition (％) For API 5L X70 PSL1
Chemical Composition of API 5L Grade X70 LSAW Steel Pipe:
Grade and Chemical Composition (％) For API 5L X70 PSL2
Mechanical Properties of API 5L Grade X70 LSAW Steel Pipe:
Mechanical Properties of API 5L X70 (PSL1):
|Gra||Yield Strength(MPa)||Tensile Strength(MPa)||Elongation A%|
|psi||MPa||psi||MPa||Elongation (Min )|
Mechanical Properties of API 5L Grade X70 LSAW Steel Pipe(PSL 2):
|Grade||Yield Strength (MPa)||Tensile Strength (MPa)||Elongation A%||Impact (J)|
|psi||MPa||psi||MPa||Elongation (Min )||Min|
Permissible Variations in Weight and Dimensions
Tolerance for Diameters of Pipe Body
|Size||Tolerance (with respect to specified outside diameter)|
|<2 3/8||+ 0.016 in., - 0.031 in. (+ 0.41 mm, - 0.79 mm)|
|> 2 3/8 and ≤4 1/2, continuous welded||±1.00%|
|> 2 3/8 and < 20||±0.75%|
|> 20. seamless||± 1.00%|
|>20 and <36, welded||+ 0.75%.-0.25%|
|> 36, welded||+ 1/4 in.. - 1/8 in. (+ 6.35 mm, -3.20 mm)|
In the case of pipe hydro-statically tested to pressures in excess of standard test pressures, other tolerances may be agreed upon between the manufacturer and the purchaser.
Tolerance for Diameter at Pipe Ends
|Size||Minus Tolerance||Plus Tolerance||End-to-End Tolerance||Out-of-Roundness|
|Diameter, Axis Tolerance (Percent of Specified OD)||Maximum Differential Between Minimum and Maximum Diameters (Applies Only to Pipe With D/t≤75)|
|≤10 3/4 l&V4||1/64(0.40mm)||1/16(1.59mm) mm)||—||—|
|>10 3/4 and ≤20||1/32 (0.79 mm)||3/32 (2.38 mm)||—||—||—|
|> 20 and≤ 42||1/32 (0.79 mm)||3/32(2.38 mm)||b||± 1%||<0.500 in. (12,7 mm)|
|>42||1/32 (0.79 mm)||3/32 (2.38 mm)||b||± 1%||£ Q625 in. (15.9 mm)|
Out-of-roundness tolerances apply to maximum and minimum diameters as measured with a bar gauge, caliper, or device measuring actual maximum and minimum diameters.
The average diameter (as measured with a diameter tape) of one end of pipe shall not differ by more than 3/32 in. (2.38 mm) from that of the other end.
Tolerances for Wall Thickness
|Size||Type of Pipe||Tolerance1 (Percent of Specified Wall Thickness}|
|Grade B or Lower||Grade X42 or Higher|
|<2 7/8||All||+20.- 12.5||+ 15.0.-12.5|
|>2 7/8and<20||All||+ 15,0,-12.5||+ 15-I2.5|
|>20||Welded||+ 17.5.-12.5||+ 19.5.-8.0|
|>20||Seamless||+ 15.0.-12.5||+ 17.5.-10,0|
Where negative tolerances smaller than those listed are specified by the purchaser, the positive tolerance shall be increased to the applicable total tolerance range in percent less the wall thickness negative tolerance.
Tolerance for Weight
|Single lengths, special plain-end pipe or A25 pipeSingle lengths, other pipeCarloads.GradeA25,40,000lb(18 144kg)or moreCarloads, other than Grade A25,40.0001b (18 144 kg) or moreCarloads, all grades less than 40000 lb (18 144 kg)Order items. Grade A25. 40.000 lb (18 144 kg) or moreOrder items, other than Grade A25,40,000 lb (18 144 kg) or moreOrder items, all grades, less than 40.000 lb (18 144 kg)||+ 10.-5.0+ 10,- 35-2.5-1.75-15-3.5-1.75 -3.5|
1. Weight tolerances apply to the calculated weights for threaded-and-coupled pipe and to the tabulated or calculated weights for plain-end pipe. Where negative wall thickness tolerances smaller than those listed in above table are specified by the purchaser, the plus weight tolerance for single lengths shall be increased to 22.5 percent less the wail thickness negative tolerance.
2. For carloads composed of pipe from more than one order item, the carload tolerances are to be applied on an individual order item basis.
3. The tolerance for order items apply to the overall quantity of pipe shipped for the order item.
Mechanical Tests for API 5L Grade X70 LSAW Steel Pipe:
Tensile testing of the pipe body—The tensile test should be carried out in accordance with ISO6892 or ASTM A370. Longitudinal samples should be used. Twice per test unit of pipe with the same cold-expansion ratio a.b.d.
CVN impact test—The Charpy test should be carried out in accordance with ASTM A370. Twice per test unit of not more than 100 lengths of pipe with the same cold-expansion ratio a.b.d.
Hardness Test—When suspected hard spots are detected by visual inspection, hardness tests shall be carried out in accordance with ISO 6506, ISO 6507, ISO 6508 or ASTM A 370 using portable hardness test equipment and methods complying with ASTM A 956, ASTM A 1038 or ASTM E 110 respectively depending on the method Used.
Hydro-static Test—Each tube shall be subjected to the hydro-static pressure test
Bending Test— a sufficient length of pipe shall stand being bent cold through 90° around a cylindrical mandrel.
100% X-ray test for the weld seam
The ultrasonic testing
The eddy current examination
Appearance for API 5L Grade X70 LSAW Steel Pipe:
A sufficient number of visual surface imperfections to provide seasonable assurance is necessarily. The defect shall be removed or cut off within the limits of requirements on length. The finished pipe shall be reasonably straight.
Marking for API 5L Grade X70 LSAW Steel Pipe:
a.Manufacturer's name or mark
b.Specification number(year-date or required)
c.Size( OD, W.T, length)
d.Grade( A or B)
e.Type of pipe( F, E, or S)
f.Test pressure( seamless steel pipe only)
h.Any additional information specified in the purchase order.
Packing for API 5L Grade X70 LSAW Steel Pipe:
a.Bare pipe or Black / Varnish coating/Epoxy coating/3PE coating ( according to customer's requirements);
b.6" and below in bundles with two cotton slings;
c.Both ends with end protectors;
d.Plain end, bevel end(2" and above with bevel ends, degree: 30~35°), threaded and coupling;