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Hebei Allland Steel Pipe Manufacturing Co.,Ltd

Technical Standard

TECHNICAL STANDARD

1. Technical Data of Longitudinal Submerged Arc Welding

The tolerance of diameter, thickness and out of roundness(API 5L PSL1)

1

2

3

OD(mm)

Diameter tolerance

Out of roundness Tolerance


Pipe end

Pipe expect the end

Pipe end

Pipe expect the end

406≤D≤610

+/0.005Dbutmaximum+/-1.6

+/-0.0075Dbutmaximum+/-3.2

0.015D for D/t≤75,0.015D

0.020D for D/t≤75,0.01D

610≤D≤1422

+/-1.6

+/-0.005Dbutmaximum+/-4.0

but maximum15

but maximum 13

D>1422

as agreed




D stands for Diameter,"t" stands for thickness,the pipe end includes a length of 100mm(4.0in)at each of the pipe extremities


The tolerance of thickness of pipeline

Thickness (mm)

Tolerance(mm)

5

+/-0.1t

t≥15

+/-1.5


2. Structural pipe and general fluid pipe diameter, wall thickness and roundness tolerance(standard GB/T3091-2008 and equivalent standard)

1

2

3

4

OD(mm)

Diameter tolerance

Out of roundness Tolerance

Thickness tolerance permitted


Pipe end

Pipe expect the end

Pipe end

Pipe expect the end

406≤D≤508

+2.4,-0.8

+/-0.0075D

≤3mm

under OD tolerance

+/-10%t

D>508

+3.2,-0.8

+/-0.01D or +/-10.0

≤4mm

Less than the 80% of the OD tolerance

D stands for Diameter,"t" stands for thickness,the pipe end includes a length of 100mm(4.0in)at each of the pipe extremities