PD5500 and EN13445 Materials Comparison

These include: European standards (HS) European approval of materials (EAM) Particular material appraisals (PMA)
Further details on the meaning and implications of these terms can be found in Ref 3.
visual inspection: 0.7.
If necessary, the type (nature) of stress and the mechanical and technological properties of the joint must also be taken into account.
for equipment subject to destructive and non-destructive tests which confirm that the whole series of joints show no significant defects: 1,
for equipment subject to random non-destructive testing: 0.85 for equipment not subject to non-destructive testing other than
As well as being free from surface defects, steels should have a minimum elongation as specified in Section 4.1.4 and a minimum Charpy V notch of 27J for ferritic steels and 40J for steels in other material groups.
Limitation on general membrane stress
Smaller of the following -
in the case of ferritic steel including normalized (normalized rolled) steel and excluding fine-grained steel and specially heat-treated steel, 2/3 of Re/t and 5/12 of Rm/20
The PED (1)
Provision of explicit materials requirements in legislation including definitions, e.g.
Annex 1 Section 7
Re/t, yield limit, indicates the value at the calculation temperature of: - the upper flow limit for a material presenting upper and lower flow limits, the 1.0% proof strength of austenitic steel and non-alloyed aluminium, the 0.2% proof strength in other cases.
the maximum allowable pressure multiplied by the coefficient 1.43, whichever is the greater.
EN13445-2 Materials
In EN13445, the specification of materials for use in pressure equipment is contained within Part 2 Section 4.1.
EN13445-2 Materials
The annexes of EN13445-2 give details of information which relates to material usage.
Table A.1-1 gives a Group Number according to type and yield strength - also pre-heat, PWHT details etc. cf. M numbers -5500 Table A.2-1 gives the applicable thickness ranges for material
Rm/20, indicates the minimum value of the ultimate strength at 20 °C.
Rm/t, designates the ultimate strength at the calculation temperature.
The PED (2)
hardening alloys 2/3 of Re/t and 5/12 of Rm/20
The PED (3)
Introduction/reintroduction of weld coefficients
For welded joints, the joint coefficient must not exceed the following values:
in the case of non-alloy or low-alloy castห้องสมุดไป่ตู้steel, 10/19 of Re/t and 1/3 of Rm/20
in the case of aluminium, 2/3 of Re/t in the case of aluminium alloys excluding precipitation
Joint coefficients effectively reduce the design stress for main seam welds which are not subject to 100% NDE.
In EN 13445 the level of NDE is determined by the testing group (similar to the construction category in PD 5500).
Testing groups 1, 2 and 3 are subdivided into sub-groups 1a, 1b, 2a, 2b, 3a and 3b in order to reflect the crack sensitivity of the material.
A Comparison of PD5500 and EN13445
- aspects related to Design Stress
David Nash University of Strathclyde
Introduction
Aim to address the means of establishing a nominal design stress for use in calculations, and testing Examine relevant legislation (the PED) Discuss current practices (PD5500 and ASME VIII) Identify differences and changes with EN13445 An example Some personal comments
In this, pressure bearing parts should meet a number of provisions and have accompanying documentation.
In addition, materials should be assigned a group in accordance with CR ISO 15608:2000 to relate to their manufacture and inspection requirements to generic material types.
EN13445-2 Materials
EN 13445-2 Section 4.3 notes the approaches to technical Delivery Conditions. These approaches provide design stress data for use in calculations.
The PED (4)
A specified minimum hydrostatic test pressure
the hydrostatic test pressure must be no less than:
that corresponding to the maximum loading to which the pressure equipment may be subject in service taking into account its maximum allowable pressure and its maximum allowable temperature, multiplied by the coefficient 1.25 or
in the case of austenitic steel: if its elongation after rupture exceeds 30%, 2/3 of Re/t or, alternatively, and if its elongation after rupture exceeds 35%, 5/6 of Re/t and 1/3 of Rm/t
EN13445 Weld Joint Coefficients and Testing Groups