August 2008
Pipe classes for process plants Part 1: General principles for creating pipe classes based on EN 13480
Rohrklassen für verfahrenstechnische Anlagen Teil 1: Grundlagen für das Erstellen von Rohrklassen basierend auf EN 13480
P 1057-1 Supersedes PAS 1057-1:2005
Catégorie de tubes pour les unités de fabrication/de production – Partie 1: Principes généraux pour la construction de catégorie de tubes en basant sur EN 13480
Preface This Publicly Available Specification (PAS) together with its integral parts describes piping components and pipe classes for process plant piping based on EN 13480. It is intended to aid piping engineers in the application of EN 13480. To cover the requirements for piping engineering to the maximum possible extent, all users of this PAS are invited to make their contribution by submitting proposals for the improvement and further development of the PAS. The PAS comprises a selection of pipe classes with standardized content and standardized piping components so as to enable piping component manufacturers to produce larger lots of identical parts. The PAS defines standard design philosophies to pave the ground for standardizing piping components for European manufacturing sites beyond the company level. As well as the requirements of the EU Pressure Equipment Directive, the PAS takes into account requirements deriving from many years of field experience. Where European standards are used as a basis for piping engineering, the requirements laid down in the PED are deemed to be satisfied. For special applications, additional requirements may have to be specified by the user of this PAS.
Continued on pages 2 through 28
© Beuth Verlag GmbH, 2008 Alleinverkauf durch Beuth Verlag GmbH, 10772 Berlin
Ref. Nr. PAS 1057:2008-08
PAS 1057-1:2008-08
The PAS “Pipe classes for process plants” is structured as follows: PAS 1057-1
General principles for creating pipe classes based on EN 13480
PAS 1057-5
Nozzles – Special styles
PAS 1057-6
Flanges for automated welding processes – Special styles
PAS 1057-10
Technical delivery conditions for piping components of Group 1.1 alloyed and unalloyed steels with specified properties at elevated temperatures;
PAS 1057-11
Technical delivery conditions for piping components of Group 8.1 austenitic stainless steels (CR ISO 15608:2000)
PAS 1057-12
Technical delivery conditions for piping components of Group 1.2 and Group 5.1 alloyed and unalloyed steels with specified properties at elevated temperatures (CR ISO 15608:2000)
PAS 1057-100 Standard pipe classes PN 10 to PN 100, material P235GH (CA) PAS 1057-102 Standard pipe classes PN 25 to PN 100, material 16Mo3 (CC) PAS 1057-103 Standard pipe classes PN 25 to PN 100, material 16CrMo4-5 (CD) PAS 1057-122 Standard pipe classes PN 10 to PN 100, material 1.4541 (X6CrNiTi18-10) (HC)
Figure 1 — Structure of PAS 1057
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PAS 1057-1:2008-08
The contents of this document is the sole responsibility of its authors. The authors of this document are the plant operators and engineering contractors stated below. This Publicly Available Specification (PAS) has been developed by Gesellschaft für Verfahrenstechnik und Chemieingenieurwesen (GVC). The following companies are represented in the GVC Working Group “Pipe Classes”: BASF Aktiengesellschaft, Bayer Technology Services, Cognis, Degussa, Merck, Linde AG, Siemens AG A&D AS SP, Buhlmann tubes-solutions and Wacker Chemie. Plant operators and engineering contractors recognize the benefits of a European piping engineering standard and actively support the efforts to leverage the EN 13480. The EN 13480 is a sound piece of standardizing work, reflecting a high technical standard. All the more so, all users should have an interest in promoting its broad acceptance. Plans are to transfer the contents of this PAS to an EN standard at the European level. The publication of this PAS was supported by Innovation and Standardization Unit of German Institute for Standardization. In order to ensure that this PAS covers the demand for pipe classes according to EN 13480 to a maximum possible extent, all users of this PAS are requested to contribute by making available specification and pipe classes established by them to the authors. Suggestions for revisions to this PAS should be sent to: Gesellschaft für Verfahrenstechnik und Chemieingenieurwesen (GVC) Head of GVC Working Group “Pipe Classes” Mr. Ralph Harry Klaer Bayer Technology Services GmbH ENG-PLP-PIPE Uerdingen, R 85 Phone: +49 2151 88 3180 Fax: +49 2151 88 9693180 Email:
[email protected] Internet: http://www.bayer-ag.de Note: For requests for interpretation or suggestions for revision of EN 13480, please use the link to the maintenance group of the Technical Committee CEN/TC267 responsible for EN 13480. http://www.cenelec.org/Cenelec/Search/Technical+Bodies/Title+scope+officers
Revisions Revisions as against PAS 1057: 2005-10 include: a) b) c) d) e) f) g)
Reference to current gasket factors in PAS 1057-1, section 12.4.3. Notes on gasket factors as per EN 13555 in Annex B. Introduction of pipe colour coding in PAS 1057-1, Annex C. Incorporation of PAS 1057-6, Welding neck flanges for automated welding of flange/pipe joints. Incorporation of PAS 1057-12 to cover 13CrMo4-5. Material 16Mo3 from PAS 1057-10 added. Revision of the PAS 1057-101 The pipe classes have been broken down into PAS Parts 100 to 199 according to their material allocation. h) All Parts of the PAS have been editorial over-worked. German Institute for Standardization Innovation and Standardization Unit 12. August 2008
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PAS 1057-1:2008-08
Contents
Page
1
Scope ......................................................................................................................................... 6
2
Normative references ............................................................................................................... 6
3 3.1 3.2
Terms, symbols, units.............................................................................................................. 7 Terms ......................................................................................................................................... 7 Symbols and units.................................................................................................................... 8
4 4.1 4.2 4.2.1 4.2.2 4.3 4.4
General design principles........................................................................................................ 8 Design of piping components ................................................................................................. 8 Pressure-temperature ratings ................................................................................................. 9 Minimum allowable temperature TSmin ................................................................................... 9 Maximum allowable temperature TSmax ................................................................................ 10 Cyclic loading ......................................................................................................................... 10 Vacuum resistance ................................................................................................................. 10
5
Materials .................................................................................................................................. 10
6 6.1 6.2 6.3 6.4 6.5 6.6
Parameters for the design of piping components under internal pressure ..................... 10 Allowable stresses for piping components ......................................................................... 10 Allowable stresses for fasteners .......................................................................................... 11 Corrosion allowances ............................................................................................................ 11 Tolerances and allowable wall thickness minus tolerance limits ..................................... 11 Joint coefficients .................................................................................................................... 11 Test conditions ....................................................................................................................... 11
7 7.1 7.2 7.3 7.3.1 7.3.2 7.3.3 7.3.4 7.3.5
Provisions for piping components ....................................................................................... 12 General requirements for piping components .................................................................... 12 Plain pipes ............................................................................................................................... 12 Pipe fittings ............................................................................................................................. 12 General..................................................................................................................................... 12 Pipe bends (cold forming of pipes) ...................................................................................... 12 Elbows ..................................................................................................................................... 13 Reducers.................................................................................................................................. 13 Flexible piping elements ........................................................................................................ 13
8 8.1 8.2 8.2.1 8.2.2 8.2.3 8.2.4 8.2.5
Branches.................................................................................................................................. 13 Types of branch ...................................................................................................................... 13 Calculation of branches ......................................................................................................... 14 Wall thickness ratio ................................................................................................................ 15 Calculation method and selection ........................................................................................ 15 Design and fabrication notes ................................................................................................ 16 Chamfer of pipe connecting ends......................................................................................... 16 Angular offset ......................................................................................................................... 16
9 9.1 9.2
Branch tables for pipe classes.............................................................................................. 16 General..................................................................................................................................... 16 Explanatory notes on branch tables..................................................................................... 17
10
Dished ends ............................................................................................................................ 17
11 11.1 11.2
Flanges .................................................................................................................................... 17 General principles .................................................................................................................. 17 Flange facings......................................................................................................................... 17
12 12.1 12.2 12.3 12.3.1 12.4 12.4.1 12.4.2 12.4.3 12.4.4
Flanged joint ........................................................................................................................... 18 General principles .................................................................................................................. 18 Additional pipe loads, external loads ................................................................................... 18 General requirements............................................................................................................. 18 Friction coefficient µ .............................................................................................................. 18 Gaskets .................................................................................................................................... 19 Gasket types and materials ................................................................................................... 19 Gasket dimensions................................................................................................................. 19 Gasket factors......................................................................................................................... 19 Compliance with TA Luft........................................................................................................ 19
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PAS 1057-1:2008-08
Page 13 13.1 13.2
Special cases, national codes............................................................................................... 20 General requirements............................................................................................................. 20 Oxygen service ....................................................................................................................... 20
14
Specification sheets for pipe classes................................................................................... 20
ANNEX A Designation of Standard Pipe Classes (for information) .............................................. 21 A.1 General..................................................................................................................................... 21 A.2 Designation ............................................................................................................................. 21 A.3 Selecting/establishing a pipe class ...................................................................................... 21 A.4 Pipe material ........................................................................................................................... 22 A.5 Flange facing or connection type ......................................................................................... 22 A.6 Gaskets .................................................................................................................................... 22 A.7 Materials .................................................................................................................................. 23 ANNEX B Notes on Gasket Factors as per EN 13555 (for information) ........................................ 25 ANNEX C Colour Coding ................................................................................................................... 27
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PAS 1057-1:2008-08
1
Scope
This PAS defines standard principles for establishing pipe classes for industrial above-ground metallic piping systems in process plants based on EN 13480.
2
Normative references
This PAS incorporates by dated or undated reference provisions of other publications. These normative references are quoted in the respective contexts, and the associated publications are listed below. For dated references, subsequent amendments to or revisions of any of these publications apply to this PAS only when incorporated in it by an amendment or a revision. For undated references, the latest edition of the referenced publication (including amendments) applies. EN 764-1
Pressure equipment – Terminology – Part 1: Pressure, temperature, volume, nominal diameter
EN 764-2
Pressure equipment – Part 2: Quantities, symbols, units
EN 764-3
Pressure equipment – Part 3: Definition of parties involved
EN 1092-1:2007
Flanges and their joints – Circular flanges for pipes, valves, fittings and accessories, designated by PN – Part 1: Steel flanges, PN-designated
EN 1333
Flanges and their joints – Piping components – PN definition and selection
EN 1514
Flanges and their joints; Dimensions of gaskets for PN-designated flanges (Parts 1 to 7)
EN 1515-1
Flanges and their joints – Bolting – Part 1: Selection of bolting
EN 1515-2
Flanges and their joints – Bolting – Part 2: Classification of bolt materials for steel flanges, PN designated
EN 1591-1
Flanges and their joints; Design rules for gasketed circular flange connections – Part 1: Calculation method
EN 10020
Definition and classification of grades of steel
EN 10027-1
Designation systems for steels – Part 1: Steel names
EN 10253-2
Butt-welding pipe fittings – Part 2: Unalloyed and alloyed steel with specific inspection requirements
EN 10253-4
Butt-welding pipe fittings – Part 4: Austenitic and austenitic-ferritic steels with specific inspection requirements
EN 12560-5
Flanges and their joints – Gaskets for Class-designated flanges – Part 5: Metallic RTJ gaskets for steel flanges
EN 13445-2
Unfired pressure vessels – Part 2: Materials
EN 13445-3
Unfired pressure vessels – Part 3: Construction
EN 13480
Metallic industrial piping (Parts 1 to 5)
prEN 13555:2002
Flanges and their joints; gasket factors and tests methods for the application of the design rules for gasketed circular flange connections
EN 13555:2005
Flanges and their joints; gasket factors and tests methods for the application of the design rules for gasketed circular flange connections
EN ISO 4287
Geometric product specifications (GSP) – Surface texture: Profile method – Terms, definitions and surface texture parameters
CR ISO 15608:2000
Welding – Guidelines for a metallic material grouping system
PED
Pressure Equipment Directive 97/23/EC
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PAS 1057-1:2008-08
DIN V 2505:1986
Calculation of flanged joints
DIN 2526
Flanges, facing types
DIN 2605-1
Steel butt-welding pipe fittings; Elbows and bends with reduced pressure factor
DIN 2605-2
Steel butt-welding pipe fittings; Elbows and bends – Part 2: Full service pressure
DIN 2609
Steel butt-welding fittings; Technical delivery conditions
DIN 2615-1
Steel butt-welding pipe fittings; Tees with reduced pressure factor
DIN 2615-2
Steel butt-welding pipe fittings; Tees for use at full service pressure
DIN 2616-2
Steel butt-welding pipe fittings; Reducers for use at fully service pressure
DIN 2617
Steel butt-welding fittings; Caps; Dimensions
DIN 28011
Torispherical heads
DIN 28013
Ellipsoidal heads
DIN 28091 series
Technical delivery conditions for gasket sheets
AD 2000-Merkblatt W 7
Bolts and nuts of ferritic steels
BGV B 7
Accident Prevention Code – Oxygen
FDBR-Merkblatt MB 5-3
Flange connections – Allowable stresses for bolts
PAS 1050
Guidelines for the implementation of TA-Luft in the chemical and pharmaceutical industries
TA Luft
German Technical Instructions for Air Pollution Control (2002)
3
Terms, symbols, units
3.1
Terms
For the purposes of this PAS, the terms and definitions given in EN 764-3 and EN 13480-1 shall apply. In addition, the following terms are used in this PAS: Pipe class: A pipe class comprises a defined selection of piping components which satisfy the requirements for the respective pressure-temperature ratings. These include pipes, fittings (elbows, tees, reducers, branches) and pipe connections including bolts. Within a pipe class, the assigned piping components are uniquely defined, e.g. by reference to an order code. NOTE
The following components are not part of a pipe class according to this PAS and must be added by the user as required.
Gaskets; Valves; Pipe supports; Special components; special components, unlike piping components, require information in addition to the designation to ensure an unequivocal specification (e.g. special geometries).
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PAS 1057-1:2008-08
3.2
Symbols and units
For the application of this PAS, the symbols and units as given in EN 764-2 and EN 13480 apply; see Table 1. Table 1 – Symbols and Units Symbol
Description
Unit
DN
Nominal diameter (as per EN 764-1)
-
PN
PN rating (as per EN 1333)
-
PS
Maximum allowable pressure (maximum (gauge) pressure for which the pressure equipment is designed)
bar
pa
External pressure
bar
E
Modulus of elasticity
MPa
TSmax
Maximum allowable temperature (maximum temperature for which the pressure equipment is designed)
°C
TSmin
Allowable minimum temperature (minimum temperature at which the pressure equipment can be operated)
°C
Re ReHt ft Rp0,2t Rm Rp1,0t A Rmt
Yield strength
N/mm² (MPa)
Minimum specified value of the upper yield strength at design temperature when this temperature is greater than the room temperature
N/mm² (MPa)
Nominal design stress (allowable stress at design temperature)
N/mm² (MPa)
0.2 % proof strength at design temperature
N/mm² (MPa)
Tensile strength at room temperature
N/mm² (MPa)
0.1 % proof strength at design temperature
N/mm² (MPa)
Elongation at failure Tensile strength at design temperature
% N/mm² (MPa)
Z
Joint coefficient
ea
Analysis wall thickness
mm
T
Ordered wall thickness
mm
D
Outside diameter
mm
d
Inside diameter
mm
lb
Effective length of nozzle without chamfer and transition to shell outside diameter
mm
Ordered length of nozzle including chamfer and transition to shell outside diameter
mm
lord b
-
The meaning of the subscripts is as follows: a = unsupported length as per vacuum analysis; b= branch; s = shell (run pipe)
4 4.1
General design principles Design of piping components
The design takes place in accordance with EN 13480-3 to withstand internal pressure and external pressure. NOTE
Modulus of elasticity determined in accordance with EN 13480-3, Annex G.
Potential wall thinning as a result of cold bending (for pipe bends) up to a nominal size of ≤DN 150 has been taken into account for the straight pipe.
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PAS 1057-1:2008-08
The internal pressure taken as a basis for the calculation of the branches is by a factor of 1.1 higher than that for the non-weakened pipe. This approach has been selected to provide for a standard stress allowance for additional loads. NOTE
4.2
After publication of EN 10253-2 and EN 10253-4 (pipe fittings) and their available warranted, the above definitions will have to be reviewed.
Pressure-temperature ratings
The allowable temperature (TS) and the associated maximum allowable pressures (PS) are specified in the Technical Delivery Conditions of this PAS. The pressure-temperature ratings of the pipe classes have been determined in accordance with EN 1092-1:2007, Annex G. The piping components stated in the Technical Delivery Conditions of this PAS satisfy the requirements for the pressure-temperature ratings also defined in Annex G for elevated temperatures below the creep range, as illustrated in the Figure 2. All kinds of components inclusive pre-standards are included in the Annex G of EN 1092-1. Optionally, an investigation of classification of the pressure-temperature ratings in the pipe classes with Annex F of EN 1092-1 may be carried out. Only the relevant product standards which are applied in the pipe classes can be a higher pressure than in Annex G respectively.
Figure 2 – Qualitative p/t rating comparison for flange < = > piping component NOTE 1
The above requirement shall be verified for the creep range.
NOTE 2
Piping component flange material combinations are shown in the annexes to the Technical Delivery Conditions.
NOTE 3
The pressure-temperature ratings of a pipe class shall be checked against the selected gaskets and valves. Depending on the result of this check, a lower pressure-temperature rating may be needed.
4.2.1
Minimum allowable temperature TSmin
The requirements for the prevention of brittle fracture defined in EN 13480-2, Annex B (process 2) have been taken into account for the materials stated in the Technical Delivery Conditions. Until a corrected version of DIN EN 13480-2:2002-08 Annex B exists, the definitions based on DIN EN 13445-2/ prA5: 2007 Appendix B (process 2) is valid. For the minimum temperature selected, reference is made to the Technical Delivery Conditions.
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PAS 1057-1:2008-08
4.2.2
Maximum allowable temperature TSmax
The maximum allowable temperatures defined in the relevant European material standards must be observed. The maximum temperatures of the pipe classes were chosen so that the main components (pipe, fitting and flange) don’t leave the area of the time-independent. Related join elements were chosen in accordance with EN 1515-1 and 1515-2.
4.3
Cyclic loading
For piping components subject to cyclic loading, the provisions of EN 13480-3 apply.
4.4
Vacuum resistance
For vacuum resistance, the provisions of EN 13480-3 apply. The allowable external gauge pressures and/or associated lengths are shown in the pipe classes, Parts 100 to 199 of this PAS.
5
Materials
The materials are classified into groups according to CR ISO 15608:2000 (see also EN 13480-2, Table A1). Requirements for the individual materials are defined in the Technical Delivery Conditions of this PAS.
6
Parameters for the design of piping components under internal pressure
6.1
Allowable stresses for piping components
The time-independent allowable stresses for the materials covered by this PAS have been determined in accordance with EN 13480-3 and/or on the basis of the additional general design principles defined under section 4 of this PAS. The nominal design stresses must be based on the strength characteristics defined in the material standards and be calculated using the data given Table 2. The safety coefficients have been taken from EN 13480-3. Table 2 – Determination of allowable stresses Materials
Design stress (time-independent range)
Non-austenitic steels
ft = min (ReHt/1.5 or Rp0,2t/1.5; Rm/2.4)
Austenitic steels (for 30 < A < 35 %) Austenitic steels (for A > 35 %) a b
b
a
ft = min (Rp1,0t/1,5; Rm/2,4) ft = min (Rp1,0t/1.5) or min (Rp1,0/1.2; Rmt/3) b
A = elongation at failure if Rmt is satisfied
In addition to the provisions of EN 13480-3, the following approach has been adopted: The strength characteristics at room temperature specified in the EN standards apply to all materials for temperatures up to 50°C, as the changes in the mechanical properties are negligible in this temperature range (philosophy adopted by the national standards). For the remaining temperature ranges, the strength characteristics shall be determined by linear interpolation between the stated values (e.g. for 80°C between 20 and 100°C; for 120 °C between 100 and 150°C); rounding of the results shall not be allowed. NOTE 1
The strength characteristics have been taken from the EN product standards / Technical Delivery Conditions applicable at the time of publication of this PAS.
NOTE 2
The allowable stresses stated in Table 2 have been taken into account for each design and test load case.
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PAS 1057-1:2008-08
NOTE 3
6.2
Should the EN product standards / Technical Delivery Conditions for piping components be revised to provide for lower strength characteristics and larger tolerances, the design of the piping components will have to be reviewed by the user of this PAS. If required, adjustments shall be made, e.g. to the wall thickness.
Allowable stresses for fasteners
In addition to EN 13480-3, Annex D.4.3 “Bolting”, the following provision applies: The allowable stresses for bolts shall be determined on the basis of the design principles defined in EN 13480-3, section 5.2.1, and/or 5.2.2 and/or 5.3. NOTE 1
The determination of the allowable stresses for bolts in accordance with EN 13480-3 Annex D.4.3 “Bolting” is likely to result in a high proportion of overloaded bolts. When adopting the philosophy of the national design code AD 2000-Merkblatt B 7 Chart 3, the approach will be similar to that described above. Depending on the bolt type or the bolted-up condition, this design code uses lower safety coefficients. For materials without known yield strength, more stringent safety coefficients will be required for the tensile strength. This is also the approach adopted by DIN V 2505.
NOTE 2
For the determination of allowable bolt stresses, see also FDBR-Merkblatt MB 5-3.
6.3
Corrosion allowances
Unless otherwise specified in the Technical Delivery Conditions, the following corrosion allowances apply (see Table 3): Table 3 – Corrosion allowances
a
Materials
Corrosion allowance (mm)
Ferritic
1.0
Austenitic
0.0
The above corrosion allowances are based on the assumption of a corrosion rate of 0.1 mm/a. Any greater allowances for special corrosion conditions shall be separately agreed.
NOTE 1
The piping components and (as applicable) the wall thickness series defined in the Technical Delivery Conditions of this PAS take into account the corrosion allowances set out in Table 3.
NOTE 2
The user of this PAS may specify corrosion allowances other than those indicated in Table 3, subject to verification by calculation; if necessary, the wall thickness series shall be adjusted accordingly.
6.4
Tolerances and allowable wall thickness minus tolerance limits
The calculation of the piping components takes into the account the nominal dimensions and the allowable wall thickness minus tolerance limits provided for by the component standards stated in the Technical Delivery Conditions.
6.5
Joint coefficients
A joint coefficient of Z = 1 has been taken into account for all piping components covered by this PAS.
6.6
Test conditions
The requirements of EN 13480-3, section 5.3.2.2 and EN 13480-5, section 9.3.2.2 are satisfied. NOTE 1
16Mo3: If the pressure-temperature rating is constant up to a temperature of 200 °C, the f(20°)/f(200°) ratio governs the magnitude of the test pressure for piping components covered by this PAS.
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PAS 1057-1:2008-08
NOTE 2
7 7.1
13CrMo4-5: If the pressure-temperature rating is constant up to a temperature of 250 °C, the f(20°)/f(250°) ratio governs the magnitude of the test pressure for piping components covered by this PAS.
Provisions for piping components General requirements for piping components
In the absence of European product standards, the relevant DIN standards have been taken as a basis. The minimum wall thickness is 0.9 % of the nominal outside diameter, however, in no case less than 2.0 mm. If in the order a color marking agreed, the requirements of Annex C applies. Where the Technical Delivery Conditions permit alternative manufacturing methods or materials, the characteristics and tolerances for the most severe case have been taken as a basis for the calculation. Additional requirements, component descriptions and wall thicknesses are defined in the Technical Delivery Conditions of this PAS. NOTE
The general requirements here defined are based on aspects of economics and availability/stockkeeping. They have been taken into account in the stress analyses. Users of this PAS may depart from these requirements provided that the suitability of the piping components is demonstrated by a stress analysis.
7.2
Plain pipes
Plain pipes are specified in accordance with the Technical Delivery Conditions of EN 10216 and EN 10217.
7.3
Pipe fittings
7.3.1
General
Pipe fittings are specified in accordance with the dimensional standards DIN 2605-1, DIN 2605-2, DIN 2615-1, DIN 2615-2, DIN 2616-2 and DIN 2617, and basically meet the requirements of DIN 2609. 7.3.2
Pipe bends (cold forming of pipes)
The following requirements shall apply to the fabrication of pipe bends of non-austenitic and austenitic stainless steels having a yield strength of up to Re ≤ 355 MPa. The wall thicknesses of pipe bends shall be calculated in accordance with the requirements laid down in EN 13480-3, Annex B. The out-of-roundness of pipe bends must not exceed the tolerances defined in EN 13480-4. The maximum allowable pressures indicated in the Technical Delivery Conditions take into account pipe bends of up to and including DN 150. For nominal diameters of up to and including DN 150, mechanical bending shall be carried out in the cold condition, free from creases and corrugations, using a radius of bend conforming to Type 5 of DIN 2605. From DN 200, elbows shall be used. On longitudinally welded pipes, the weld shall be located in the tensile zone at an angle of approx. 45° to the bending plane. All media used for bending (e.g. lubricants) shall be completely removed from the finished bend. In the installed condition, the pipe bends shall be free from oil and grease and exhibit a metallic bright surface. The surface finish of pipe bends shall conform to the requirements of EN 13480-4, section 7.5. The wall thickness reduction along the fibre in tension (extrados) shall not exceed 15 %. The general requirements of EN 13480-4, section 7 “Bending and other Forming Processes” shall be observed.
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PAS 1057-1:2008-08
The maximum allowable angular offset of the bend in the bending plane (angle of bend) and normal to the bending plane (tilt angle) shall not exceed ± 1°. Heat treatment after cold forming shall be carried out in accordance with EN 13480-4, section 7.2.2. NOTE 1
For pipes stated in the Technical Delivery Conditions of this PAS, the wall thinning resulting from the bending process shall be taken into account in the calculation as provided for by EN 13480-3, Annex B. In the standard pipe classes, the pipes requiring no further verification for the respective pressure rating are marked accordingly.
NOTE 2
Bending of hot-galvanized pipes shall not be allowed.
7.3.3
Elbows
Elbows are calculated with EN 13480-3, Annex B and are specified in accordance with DIN 2605-1 or DIN 2605-2. Criteria for selection are as follows: Where no adequate elbow to DIN 2605 was found, it has been checked whether an elbow to DIN 2605-2 may be used. The different allowances for wall thickness minus tolerances of pipes and elbows have been taken into account. 7.3.4
Reducers
Reducers according to DIN 2616-2 are used exclusively. Based on the required pipe wall thickness, a reducer of the same or the next greater wall thickness has been selected. This will ensure that reducers withstand the internal pressure of the piping line. The different allowances for wall thickness minus tolerances of pipes and elbows have been taken into account. NOTE
7.3.5
It is recommended to use decrements of not more than 3 DN.
Flexible piping elements
Flexible piping elements (expansion joints, corrugated hose) shall be designed and fabricated in accordance with EN 13480.
8
Branches
8.1
Types of branch
A distinction is made between the following branch types (see Table 4): The branch types are tabulated according to economic and availability criteria. Table 4 – Branch Types
Type A
Fig. 3 Extruded outlet
Fig. 4 Unreinforced branch
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PAS 1057-1:2008-08
Type B Type W Fig. 5 Type B : Reinforced branch
Fig. 6 Type W : Reinforced branch
Type S
Fig. 7 Reinforcing pad
Type T1 Type T2 Fig. 8 Type T1: Tee “with reduced pressure factor”
Fig. 9 Type T2: Tee “for full service pressure”
Type G
Fig. 10 Reinforced run
Type F
Fig. 11 Welded Tee NOTE 1
Extruded outlets should not be used in the creep range.
NOTE 2
Reinforcing pad: with this type of reinforcement, it must be taken into account that the thickness of the reinforcement pad is taken as the wall thickness of the run type. Reason: This material is directly available for fabrication.
8.2
Calculation of branches
Type A, B, W, G and F branches (see Table 4) have been calculated using the area replacement method (EN 13480-3, section 8.4). The opening is treated as isolated opening. The effects of loads and/or moments other than those caused by internal pressure have been considered by providing for a stress reserve of 10 %. The maximum allowable pressures (PS) indicated in the Technical Delivery Conditions of this PAS take into account this requirement. The EN 13480-3 doesn’t provide a workable approach for reduction of pressure carrying crosssections and the increase in the pressure loaded surfaces through the radius of Tees at the transitions between the main pipe and branch, which is created due to the form of the Tees (form T1 and T2). In
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PAS 1057-1:2008-08
accordance with EN 13445-3, Section 9.5.7.3 by the calculation for the maximum pressure in Tees the cross-sectional area was multiplied by a factor of 0.9. For the mutual interferences between adjacent nozzles (minimum distance to next discontinuity), the provisions of EN 13480-3, section 8.3.2 apply. Where the ligament between any two openings is less than 2 (D ∗ e as , a recalculation as per EN 13480-3, section 8.5 will be required. The requirements set out above relate to so-called straight branches (90° branch ± 5°). Branches with other angles (oblique branches) shall be separately specified. 8.2.1
Wall thickness ratio
The allowable branch-to-run pipe wall thickness ratio has been determined as shown in Fig. 12. The wall thickness ratio has been calculated using the analysis wall thicknesses (ratio eab / eas). Allowable stress < 250 N/mm²
Allowable stress > 250 N/mm²
ea b / ea s
ea b / ea s
d b / dS
d b / dS
Figure 12 – Wall thickness ratio
8.2.2
Calculation method and selection
The required branch type and the wall thicknesses are determined by iteration. Tees to DIN 2615 are generally included in the pipe classes whenever they satisfy the requirements. They may be used as an alternative to branch types A, B or W in applications where there are special requirements, e.g. major nozzle loads. Branch types B and W shall not be allowed for branch connections of equal diameter run and branch pipes. The different allowances for wall thickness minus tolerances of pipes and tees have been taken into account. For the iteration, the wall thickness of the nozzle is increased up to the maximum value as per Figure 12 in a first step. If the inside diameter reduction of the reinforced branch pipe exceeds 12.5 % of the inside diameter of the unreinforced run pipe, the outside diameter is increased (→ Type W). In the case of larger inside diameter differences, this has been marked and commented in the branch table. If branch types B and W are not sufficiently safe and if no Tee as per DIN 2615-1 (T1) or DIN 2615-2 (T2) is available, the wall thicknesses are increased by increments (Type G and F). Here as well, the respective outside diameter is increased if the necking exceeds 12.5 %. NOTE
As an alternative to “T2” Tees, “T1” Tees of the next greater or next-but-one greater wall thickness series may be used subject to verification by calculation. In such a case, it may become necessary to chamfer the ends of the “T1” Tees to match the relevant pipe wall thickness.
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PAS 1057-1:2008-08
8.2.3
Design and fabrication notes
Openings for branches on longitudinally welded pipes should be located outside the 3 ∗ eas zone of the weld, where practical. Otherwise, the area of the openings must be accessible for non-destructive weld testing. For the nozzle length lord b, a standard dimension is specified in PAS 1057-5. This length may be adjusted to suit the specific installation conditions provided that the effective length lb of reinforced nozzles shall not be less than specified. The relevant requirements of EN 13480-3 shall be observed. lord b ≥ lb + x and lord b ≥ – 50 mm where x = additional length of nozzle for the transition to the outside diameter of the shell (run pipe) NOTE
8.2.4
For details of the effective length lb of reinforced nozzles, see PAS 1057-5.
Chamfer of pipe connecting ends
Where required, the pipe connecting dimensions shall be established by chamfering the inner or outer diameter as shown in Figure 13. NOTE
8.2.5
For further details, please see PAS 1057-5.
Angular offset
For piping installed at a slope, an angular offset of the branch may become necessary. For branch types A, B, G, F and W, a maximum angular offset relative to the axis perpendicular to the longitudinal axis of the run pipe as shown in Figure 14 is permitted. For greater angular offsets, a recalculation of the branch will be required.
Figure 13 – Chamfer of pipe connecting ends
9
Branch tables for pipe classes
9.1
General
Figure 14 – Angular offset
The branch combinations for the individual pipe classes are documented in the form of so-called branch tables. For explanatory notes on the branch tables and the terms and symbols used, see Figure 15. The pressure-temperature ratings are those of the associated pipe class. NOTE
16
The branch tables are included in the standard pipe classes.
PAS 1057-1:2008-08
9.2
Explanatory notes on branch tables
The branch table shows the eligible branch types for each pipe class and PN rating. Where no branch types are indicated for a specific nominal size, the respective branches shall be designed for the specific case. Ordered wall thickness ‘T’ of run pipe / branch pipe e.g. A, B, etc. identification letter for branch types allowed for the nominal diameter / PN range. For branch types B and W, the wall thickness in mm is indicated in addition. For types T1 and T2, the nominal wall thickness of the run pipe to DIN 2615 is indicated in addition.
Figure 15 – Explanatory notes on branch tables
10
Dished ends
Dished ends provided for by this PAS are caps to DIN 2617 or torispherical ends to DIN 28011. For the calculation of the maximum pressure, the condition r ≥ 2e has been used in accordance with DIN EN 13445-3, Section 7.5.3.1. For small dimensions which exceed the ranges, the calculation of a maximum pressure will be reduced in wall thickness to e = r/2. NOTE
Other types of ends (e.g. to DIN 28013) may be specified by the user of this PAS subject to verification by calculation.
11
Flanges
11.1
General principles
Standard flange types provided for by this PAS are Type 11 (welding neck flange) and Type 05 (blind flange) flanges to EN 1092-1:2007. NOTE
11.2
Other flange types may be used subject to verification by calculation according to EN 1591-1 (e.g. Type 4 lap joint flanges together with Type 34).
Flange facings
Table 5 shows a selection of flange facings. Flange facings are defined in pipe classes PAS 1057-100 pp.
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PAS 1057-1:2008-08
Table 5 – Comparison of Flange Facings
Designation to DIN 2526
Type A Type B Type C Type E Type F Type N a b
c
Requirements for facing
None Rz=160, turningc Rz=160, turningc Rz=16, turningc -
Surface roughness (in µm) Ra Rz
Designation to EN 1092-1
Type A Type A Type B1 b Type B2 b Type C Type D
min.
max.
min.
max.
3,2 3,2 3,2 0,8 0,8 0,8
12,5 12,5 12,5 3,2 3,2 3,2
12,5 12,5 12,5 3,2 3,2 3,2
50 50 50 12,5 12,5 12,5
Ra and Rz are defined in EN ISO 4287. B1 and B2 are raised face flange facings (Type B) with different surface roughness specifications for the following applications: B1 for PN 2.5 to PN 40; B2 for PN 63 and PN 400. “Turning” designates any machining method producing either serrated concentric or serrated spiral grooves.
NOTE 1
For material in stock, the different dimensions and surface roughness values may have to be taken into account.
NOTE 2
The use of Type B1 or B2 surface roughness shall be coordinated with the gasket manufacturers for the specific gasket type and material.
12
Flanged joint
12.1
General principles
A flanged joint consists of a flange pair, bolt, nuts and a gasket. Components of flanged joints shall be selected in accordance with the requirements of EN 13480-3, Annex D “Flanges”, D 4.2. The flanged joints have been calculated in accordance with the requirements of EN 1591-1 for the installation, testing and operation load cases. NOTE
12.2
For the selection of bolts and nuts, see EN 1515-1 and EN 1515-2.
Additional pipe loads, external loads
For the consideration of additional pipe loads, EN 1092-1:2007, Annex E applies. NOTE
12.3
At elevated temperatures (> 50 °C), the additional pipe loads determined in accordance with EN 1092-1:2007, Annex E must be reduced in proportion to the ratio of the nominal design 2 stress at temperature (ft) to 140 N/mm .
General requirements
Factors to be taken into account in the determination of the tightening torques include bolt material, type of flange facing, gasket and the friction coefficient µ. Tightening torques shall be determined in accordance with EN 1591-1. 12.3.1 Friction coefficient µ The friction coefficient µ is an average value which considers the friction on both threads and the nut (or bolt) contact faces (see EN 1591-1, Annex D). µ = 0.10 – 0.15 for smooth lubricated surfaces µ = 0.15 – 0.25 for average “normal“ conditions µ = 0.20 – 0.35 for rough, dry surfaces
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PAS 1057-1:2008-08
NOTE 1
Friction coefficient µ (see also EN 1591-1, Annex D)
NOTE 2
It is recommended to select an average friction coefficient of µ = 0.2 as the “normal“ condition (EN 1092-1:2007 Annex E).
NOTE 3
Flange assembly shall be by controlled tightening methods only (see EN 1591-1, Annex C)
12.4
Gaskets
12.4.1 Gasket types and materials Gasket types and materials shall be defined by the user. The chemical resistance of the selected gasket types to the contained fluid shall be verified by the user. As a rule, fabric and combined metal/fabric gaskets (jacketed gaskets, spiral-wound gaskets, graphite gaskets with spiked or expanded metal foil reinforcements or metal foil inlays, corrugated gaskets and shims for serrated gaskets) shall be asbestos-free. Materials of non-metallic sheet gaskets shall conform to the applicable standards of the DIN 28091 standard series “Technical Delivery Conditions for Sheet Gaskets”. Once the DIN standards have been superseded by EN standards, the latter shall be applied. NOTE
As recommended in Annex A, the pipe class designation shall be complemented by an identification code for gaskets.
12.4.2 Gasket dimensions For the gasket dimensions of PN-designated flanges, the EN 1514 standard series, Parts 1 through 7 applies. 12.4.3 Gasket factors In EN 1092-1:2007, the minimum gasket seating stress is taken as Qmin = 25 N/mm² for pressure ratings up to and including PN 63 and Qmin = 50 N/mm² for pressure ratings from PN 100. The strength requirements shall be deemed to be satisfied if Qmin/0.1 ≤ 25 N/mm² and Qmin/0.1 ≤ 50 N/mm² are satisfied respectively. Should greater Qmin/0.1 values be required, a strength calculation to EN 1591-1 will be required. NOTE 1
For flanges with flat gaskets up to PN 63: strength calculation to EN 1514-1; for flanges with spiral-wound gaskets from PN 100: strength calculation to EN 1514-2 (see Annex to EN 1092-1:2007).
Gasket factors shall be determined in accordance with EN 13555. The specific service conditions shall be subject to coordination with the gasket manufacturer. The gasket factors taken into account by the user shall be documented in the pipe classes. Current gasket parameters can be viewed on www.gasketdata.org or be obtained from the respective gasket manufacturers. NOTE 2
When using metallic gaskets, e.g. lens or ring-joint gaskets, the hardness limitations specified in EN 12560-5 shall be observed.
For notes on the gasket factors according to EN 13555, please see Annex B to this PAS. 12.4.4 Compliance with TA Luft Where compliance with TA Luft is required, only TA-Luft-certified gaskets shall be allowed. For information on implementation, please see PAS 1050.
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PAS 1057-1:2008-08
13
Special cases, national codes
13.1
General requirements
If additionally agreed, national codes shall be taken into account.
13.2
Oxygen service
When using this pipe class concept for oxygen service in Germany, the additional requirements defined in BGV B 7 (previously VGB 62) shall be observed. Gasket materials require a certification by Bundesanstalt für Materialforschung und -prüfung (BAM). “Free from oil and grease” shall be specified, indicating the associated cleanliness class.
14
Specification sheets for pipe classes
The designation system presented in Annex A may be used for the designation of pipe classes. The pipe class designation is composed of the pressure rating to EN 1333, two code letters for the material group and material(s), the code letter for the facing and/or type of connection plus a consecutive number to differentiate between variants. A specification sheet shall be prepared for each pipe class, using the following structure:
Designation Notes on pipe class Pipe material and type of facing Allowable temperature and maximum allowable pressure Related piping components Branch table Nominal sizes, outside diameter and wall thickness Comments on piping components Previous issues Revisions
NOTE
20
A selection of standard pipe classes is given in Parts 100 through 199 of PAS 1057.
PAS 1057-1:2008-08
ANNEX A Designation of Standard Pipe Classes (for information) A.1
General
This Annex defines the designation system for pipe classes. NOTE
A.2
It is recommended that the designation of existing pipe classes be adjusted to the system described below.
Designation
The designation of a pipe class is composed of the pressure rating (PN), the code letters for the pipe material, a consecutive number, the gasket identification code and the identification code for the flange facing and/or type of connection. Digits 7 and 8 are reserved for the consecutive number to permit further differentiations within a material group or a material, e.g. manufacturing method. The consecutive numbers shall be assigned as follows: 01 through 19 shall be used for the pipe classes 20 thought 99 may be used for project- or plant-specific definitions:
A.3
Selecting/establishing a pipe class
In a first step, the pressure rating, pipe and gasket materials are derived from the specific service conditions (e.g. PS, TS, fluid). Based on the requirements so established, the user of this PAS may then select a suitable pipe class or define a new pipe class.
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PAS 1057-1:2008-08
A.4
Pipe material
Materials are classified into groups as shown in Table A1. The code letter defined in this Annex is complemented by a second code letter (see A.7 below). The material designation of a pipe class is governed by the pipe material. The exact material specification of the individual piping components of a pipe class is defined by the associated documentation. X, when used as second code letter, covers all unlisted materials of a group. Table A.1 – Classification into material groups Group
A.5
Steel grade
B
Unalloyed steels with specified properties at room temperature
C
Unalloyed and alloyed steels with specified properties at elevated temperatures
F
Alloyed fine-grained structural steels and alloyed steels with specified properties at low temperatures
H
Stainless steels
X
Other materials
Flange facing or connection type
Flange facings are identified in accordance with EN 1092-1:2007, complemented by the facing and connection types listed in Table A.2 below. Table A.2 – Flange facings a and types of connection A
Flat face
12.5 < Rz ≤ 50
B
Raised face
12.5 < Rz ≤ 50 (B1) 3.2 < Rz ≤ 12.5 (B2)
C
Tongue
D
Groove
E
Male and female (EN 1092-1:2007)
F G H
a
A.6
M
Welded diaphragm seal
L
Lens gasket
J
Ring joint
S
Welding end
W
Olive or clamping collar
Y
Female thread
Z
Male thread
For further details of flange facings, please see Table 5
Gaskets
Gaskets are classified into groups as shown in Table A3. Materials and material combinations, e.g. in the case of spiral-wound gaskets, are differentiated by consecutive numbers and documented in the pipe classes.
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PAS 1057-1:2008-08
When changing the gasket material, it may become necessary to also change the flange and bolt assignment (type of facing, gasket seating stress) For an unequivocal specification of the gasket, the DN, pressure rating, gasket group, consecutive number and type of facing must be indicated. Table A.3 – Gasket groups
A.7
F
Fabric gaskets, also with inner flare
G
Graphite gaskets, also with inner flare
K
Serrated gaskets
M
Metal gaskets (e.g. lens ring, ring joint)
R
Elastomeric gaskets
S
Spiral-wound gaskets
T
PTFE gaskets, including jacketed gaskets
X
Other gaskets
Materials
NOTE 1
The material classification is based on EN 10020 and the designation system for steels defined in EN 10027-1.
NOTE 2
The tables show a selection of steels meeting the specifications of the Technical Delivery Conditions of this PAS. For materials not listed, the user of this PAS may continue this coding as appropriate.
NOTE 3
The materials listed in the subsequent tables A.4 to A.7 are considered to meet the basic safety requirements of the PED (see EN 13480-2, Table A.3). Table A.4 – B – Unalloyed steels with specified properties at room temperature Material group as per CR ISO 15608:2000 BA
P235TR2
-
BX
Others
-
Table A.5 – C – Unalloyed and alloyed steels with specified properties at elevated temperatures Material group as per CR ISO 15608:2000 CA
P235GH
1.1
CB
P265GH
1.1
CC
16Mo3
1.2
CD
13CrMo4-5
5.1
CE
10CrMo9-10
5.2
CX
Others
-
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PAS 1057-1:2008-08
Table A.6 – F – Alloyed fine-grained structural steels and alloyed steels with specified properties at low temperatures Material group as per CR ISO 15608:2000 FA
P215NL
1.1
FB
P255QL
1.1
FC
P355NH
1.2
FD
P355NL1
1.2
FE
P355NL2
1.2
FF
12Ni14
9.2
FX
Others
-
Table A.7 – H – Stainless steels Material group as per CR ISO 15608:2000
24
HA
1.4301 (X5CrNi18-10)
8.1
HB
1.4306 (X2CrNi19-11)
8.1
HC
1.4541(X6CrNiTi18-10)
8.1
HD
1.4571 (X6CrNiMoTi17-12-2)
8.1
HE
1.4401 (X5CrNiMo 17-12-2)
8.1
HF
1.4404 (X2CrNiMo 17-13-2)
8.1
HG
1.4462 (X2CrNiMoN22-5-3)
10.1
HX
Others
-
PAS 1057-1:2008-08
ANNEX B Notes on Gasket Factors as per EN 13555 (for information) Table B.1 – Notes on gasket factors to EN 13555 Factor
Description
QA
actual stress to seal on assembly
Qmin(L)
QSmin(L)
PQR
QSmax
EG
Note
The gasket factor QA is not stated in EN 13555, but results from the iterative calculation to EN 1591. QA corresponds to the desirable maximum possible gasket seating stress, once the allowable stress utilization factor for bolts, flanges or gaskets is attained. See also Qmin(L). required minimum stress to seal The tightness class will normally be L0,1 [0.1 mg/(m.s)]. Lower on assembly for Tightness tightness classes may be agreed. Class L In most cases, the actual stress to seal on assembly QA will be greater than Qmin(L).To attain the actual stress to seal, the calculation as per EN 1591-1 should be performed in such a way that the maximum allowable stress utilization factor of the flanges or bolts or gasket is reached. required minimum stress to seal QSmin(L) is primarily a function of the maximum stress to seal after unloading for Tightness applied on assembly QA. Note: The QSmin(L) value used in the strength calculation of the flanged joint must not be less than Class L 5 N/mm². Stress to seal ratio before and As there is only a limited number of PQR values, values assigned after relaxation to the next larger stiffness and the next higher temperature should always be used for the calculation of the flange joint. NOTE PQR ≤ 1 Maximum stress to seal that QSmax values assigned to the next higher temperature should be may be applied to the gasket used for the calculation of the flange joint. during assembly and at operating temperature without the gasket suffering damage Secant unloading modulus EG values assigned to the next higher temperature should be (modulus of elasticity) used for the calculation of the flange connection.
The calculations in EN 1092-1:2007 are based on gasket factors to prEN 13555:2002. As the changes in prEN 13555:2005 as against EN 13555:2002 are not documented in EN 1092-1:2007, these are briefly described below. The geometries and pressure-temperature ratings given in EN 1092-1:2007 remain unaffected by these changes. Table B.2 – Changes in prEN 13555:2005 versus prEN 13555:2002 prEN 13555:2002 QSmin(L) QI/p
EN 13555:2005 QSmin(L) QSmin(L)
gC
PQR
Note No change According to EN 13555, QSmin is determined from the unloading part of the leakage rate curve and is normally available as tabular value. In EN 1092-1:2007, QI/p is taken as 1.6 which, at an internal pressure of 40 bar, for instance, corresponds to QI = QSmin = 1.6 * 4N/mm² = 6.4 N/mm². Here, there are fundamental differences in the determination of the gasket factors and partly also in the test results. While the differences in the results (gC as against PQR) are negligible for sealing materials subject to little creep, e.g. graphite, they are significant for materials like PTFE. EN 1591-1 is currently being revised in this respect. Pending publication of the revised version of EN 1591-1, PQR shall be taken as 1 in the calculation. The following criterion must be satisfied: QA * PQR ≥ QSmin(L) (continued)
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PAS 1057-1:2008-08
Table B.2 Cont’d – Changes in prEN 13555:2005 as against prEN 13555:2002 prEN 13555:2002 E0, K1
EN 13555:2005 EG
Qmax
QSmax
NOTE The gasket factors E0 and K1 denote the slope and/or the y-intercept of a linear equation. Today it is known that a linear relationship between the modulus of elasticity and the gasket seating stress exists only for very few gasket materials. For this reason, K1 and E0 have been replaced by EG. EG can normally be read from the table for the relevant pressure and gasket seating stress. No changes
gc can be determined from PQR in accordance with the following equation: Symbols EGI KI XG
gc =
Modulus of elasticity of gasket (gasket factor as per EN 13555) [MPa] Rigidity of flanged connection [N/mm] Axial modulus of elasticity of gasket [1/mm]
PQR 1+
EGI * (1 − PQR ) KI * X G
Source: Proposal WG 10 CEN/TC 74
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PAS 1057-1:2008-08
ANNEX C Colour Coding (for information)
The colour coding of piping components by materials serves to ensure positive material identification during field installation, especially when unstamped piping components are left over from cutting operations. Table C.1 – Colour coding of piping Material
Material group Designation Unalloyed steels
Unalloyed and alloyed steels at elevated temperatures
Alloyed finegrained structural steels and alloyed steels at low temperatures
Stainless steels
P235TR2 P235GH P245GH P250GH P265GH P280GH P295GH 16Mo3 13CrMo4-5 10CrMo9-10 P215NL P255QL P355NH P355NL1 P355NL2 12Ni14 X5CrNi18-10 X2CrNi18-9 X2CrNi19-11 X6CrNiMoTi 18-10 X6CrNiMoTi 17-12-2 X5CrNiMo 17-12-2 X2CrNiMo 17-13-2 X2CrNiMoN 22-5-3
Material No. 1.0255 1.0345 1.0352 1.0460 1.0425 1.0426 1.0481 1.5415 1.7335 1.7380 1.0451 1.0452 1.0565 1.0566 1.1106 1.5637 1.4301 1.43071 1.43062 1.4541 1.4571 1.4401 1.4404 1.4462
Base colour white yellow yellow yellow orange orange orange orange orange orange blue blue blue blue3 red red red red
Colour coding 1st additional colour green red silver yellow blue green yellow red green green
2nd additional colour orange
Colour coding shall be by indelible and weather-resistant paint. The paint used shall be free from substances likely to damage the material to be colour-coded (e.g. sulphur on nickel or chloride on austenitic steels). The colour coding shall be applied in the form of one or two/three parallel horizontal stripes extending over the full length of the components. Weld bevels shall be kept free from paint. The colour shades tabulated in Table C.2 shall be used: Table C.2 – RAL colours Identification colour white yellow red violet brown
RAL number 9010 1012 3003 4001 8001
Identification colour green black blue orange silver
RAL number 6010 9005 5010 2000 9006
Where piping components have already been colour-coded, the heat-affected zone shall be stripped of paint prior to welding or heating (heat treatment, hot bending etc.). The use of an open flame torch for paint removal shall not be allowed.
1
Welded pipe Seamless pipe 3 Piping components fabricated from material nos. 1.4541 and 1.4550 shall not be colour-coded. If, apart from material no. 1.4541, the use of material no. 1.4550 is specified for a plant, the colour coding as per Table C.1 shall be field-applied to one of the two material numbers. 2
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PAS 1057-1:2008-08
Where the colour coding has been obliterated or hidden by a surface treatment prior to installation, e.g. by the application of a corrosion protection coating, it shall be reapplied to the piping component after the surface treatment.
28
