EN 10216-4 Non-alloy and alloy steel tubes for pressure purposed with specified low temperature

Non-alloy and alloy steel

Fine grain steel pipes for pressure purposes are used in power engineering and in associated fields of industry. They are used as pipes in elevated pressure installations as well as in installation where it is important to guarantee the appropriate resilience of steel in varying temperatures.

The pipes are manufactured with the diameters between 21,3 – 660 mm and with the wall thickness of up to 100 mm in the case of hot rolling, and with the diameters between 10,2 – 108 and with the wall thickness of up to 12,5 mm in the case of cold drawing. The pipes are manufactured with TC1 tests (I requirement level) and with TC2 tests (III requirement level).

Steel grades used , ,
26CrMo4-2, 11MnNi5-3, 13MnNi6-3, 12N und 14, X12Ni5, X10Ni9
Details: Table 1
Dimensions and tolerances Details: Table 2
Pipe lengths Pipes with precise lengths are manufactured with the following tolerance values:
– for pipes 0-6m -0/+15%
– for pipes 6-12m -0/+15%
– for pipes longer than 12m -0/to be negotiated
Tightness Pipes should be subject to water testing (7Mpa) or electromagnetic testing.
Straightness < 0,0015 of pipe length (below 3mm per every meter of pipe length)
Tests Details: Table 3
Table 1
Mechanical properties in room temperature for the wall thickness of up to 40 mm inclusive
Pipe type Steel grades Resistance properties
Non-alloy and with the required properties in low temperatures P215NL, P265NL
According to PN-EN -4
Upper yield limit or yield strength Re or Rp0,2 min Tensile strength Rm Elongation A min %
MPa MPa 1 t
P215NL 215 360-480 25 23
P265NL 265 410-570 24 22

 

Steel grades CHEMICAL COMPOSITION (LADLE ANALYSIS)
C% max Si% max Mn% max P% max S% max Cr% max Mo% max Ni% max Al.cał% min Cu% max Nb% max Ti% max V% max
P215NL 0,15 0,35 0,40-1,20 0,025 0,020 0,30 0,08 0,30 >\=0,020 0,30 0,010 0,040 0,02
P265NL 0,20 0,40 0,60-1,20 0,025 0,020 0,30 0,08 0,30 >\=0,020 0,30 0,010 0,040 0,02
Table 2
Outside diameter and wall thickness tolerance
Outside diameter D mm Permissible deviations of outside diameter D Permissible deviations of wall thickness t depending on the T/D ratio
<\=0,025 >0,025
<\=0,050
>0,050
<\=0,10
>0,10
D<\=219,1 +\- 1% or =\- 0,5mm depending on which is greater +\- 12,5% or 0,4 mm depending on which is greater
D>219,1 =\- 20% =\- 15% =\- 12,5% =\- 10%
Table 3
Inspection and test type Test frequency Test category
Mandatory tests Ladle analysis One per ladle 1 2
Tensile testing in room temperature One per every test pipe X X
Flattening test for D<600mm and the ratio of D<\=0,15 but T<\=40mm or ring testing for D>150mm and T <\=40mm X X
Rolling test on a mandrel bar for D<\=150mm and T<\=10mm or ring testing for D<\=114,3mm and T <\=12,5mm X X
Resilience testing at the temperature of 20 ºC X X
Tightness testing Every pipe X X
Dimensional testing X X
Visual inspection X X
NDT in order to identify longitudinal discontinuity Every pipe X X
Material identification for alloy steel X X
Optional tests Final product analysis One per ladle X X
Tensile testing at elevated temperature One per ladle and for the same thermal processing conditions X X
Resilience testing One per every test pipe X X
Resilience testing in the machine direction at the temperature of -10ºC for non-alloy steel grades X X
Wall thickness measurement at a distance from pipe ends X X
NDT in order to identify transverse discontinuity Every pipe X X
NDT in order to identify delamination X X