Bsi bs en 12007 2 2012

BSI Standards PublicationGas infrastructure — Pipelines for maximum operating pressure up to and including 16 bar Part 2: Specific functional requirements for polyethylene MOP up to and

BSI Standards Publication

Gas infrastructure — Pipelines for maximum operating

pressure up to and including 16 bar

Part 2: Specific functional requirements for polyethylene (MOP up to and including 10 bar)

This British Standard is the UK implementation of EN 12007-2:2012.

It supersedes BS EN 12007-2:2000 which is withdrawn

The UK participation in its preparation was entrusted to TechnicalCommittee GSE/33, Gas supply

A list of organizations represented on this committee can beobtained on request to its secretary

This publication does not purport to include all the necessaryprovisions of a contract Users are responsible for its correctapplication

© The British Standards Institution 2012 Published by BSI StandardsLimited 2012

ISBN 978 0 580 68891 1ICS 75.200

Compliance with a British Standard cannot confer immunity from legal obligations.

This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 August 2012

Amendments issued since publication

Date Text affected

NORME EUROPÉENNE

English Version Gas infrastructure - Pipelines for maximum operating pressure

up to and including 16 bar - Part 2: Specific functional requirements for polyethylene (MOP up to and including 10 bar)

Infrastructures gazières - Canalisations pour pression

maximale de service inférieure ou égale à 16 bar - Partie 2:

Exigences fonctionnelles spécifiques pour le polyéthylène

(MOP inférieure ou égale à 10 bar)

Gasinfrastruktur - Rohrleitungen mit einem maximal zulässigen Betriebsdruck bis einschließlich 16 bar - Teil 2: Spezifische funktionale Anforderungen für Polyethylen

(MOP bis einschließlich 10 bar)

This European Standard was approved by CEN on 24 May 2012

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member

This European Standard exists in three official versions (English, French, German) A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,

Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom

EUROPEAN COMMITTEE FOR STANDARDIZATION

C O M I T É E U R O P É E N D E N O R M A L I S A T I O N

E U R O P Ä I S C H E S K O M I T E E FÜ R N O R M U N G

Management Centre: Avenue Marnix 17, B-1000 Brussels

Contents Page

Foreword 4

1 Scope .5

2 Normative references .5

3 Terms, definitions, symbols and abbreviations 6

4 Design .7

4.1 General .7

4.2 Materials and components 7

4.3 Maximum operating pressure 7

4.3.1 General .7

4.3.2 Verification of the overall service (design) coefficient 8

4.3.3 Verification of the RCP criterion 8

4.4 Assembly techniques 10

4.5 Material properties for flow stopping by squeeze-off 10

4.6 Pipework inside buildings 10

5 Construction 10

5.1 Storage, handling and transportation 10

5.2 Jointing 11

5.2.1 General 11

5.2.2 Fusion jointing 11

5.2.3 Mechanical joints 12

5.3 Laying 12

5.4 Connection to existing systems 13

5.4.1 Static electricity 13

5.4.2 Squeeze-off 13

6 Quality control 14

6.1 Inspection prior to installation 14

6.2 Inspection during laying 14

6.2.1 Laying 14

6.2.2 Joint integrity 14

7 Pressure testing 14

Annex A (informative) Storage, handling and transportation 16

A.1 General 16

A.2 Storage 16

A.2.1 Storage conditions 16

A.2.2 Bundles 16

A.2.3 Stacking loose straight pipes 17

A.2.4 Drums and coils 17

A.2.5 Storing 17

A.2.6 First in − first out 18

A.3 Handling 18

A.3.1 General 18

A.3.2 Handling in cold weather 18

A.3.3 Straight pipes 18

A.3.4 Coils 18

A.3.5 Drums 18

A.3.6 Uncoiling 19

A.4 Transportation 19

A.4.1 Straight pipes 19

A.4.2 Coiled pipe 19

A.4.3 Drums 19

Annex B (informative) Fusion joint integrity 20

B.1 General 20

B.2 Visual inspection criteria 20

B.2.1 General 20

B.2.2 Butt fusion guidelines for the visual examination of butt fusion joints 20

B.2.3 Electrofusion 23

B.2.4 Ancillary tooling 26

Annex C (informative) Technical changes between this European Standard and EN 12007-2:2000 27

Bibliography 28

at the latest by February 2013

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights

This document supersedes EN 12007-2:2000

Annex C provides details of significant technical changes between this European Standard and the previous edition

EN 12007 Gas infrastructure ― Pipelines for maximum operating pressure up to and including 16 bar consists

of the following parts:

Part 1: General functional requirements

Part 2: Specific functional requirements for polyethylene (MOP up to and including 10 bar)Part 3: Specific functional requirements for steel

Part 4: Specific functional requirements for renovation

Part 5: Specific functional recommendations of new service lines1

According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom

1 To be published

1 Scope

This European Standard describes the specific functional requirements for polyethylene (PE) pipelines in addition to the general functional requirements of EN 12007-1 for:

a) a maximum operating pressure (MOP) up to and including 10 bar;

b) an operating temperature between -20 °C and +40 °C

This European Standard covers three types of pipe:

 PE pipes including any identification stripes;

 PE pipes with co-extruded layers on either or both the outside and/or inside of the pipe;

 PE pipes with a peelable, contiguous thermoplastics additional layer on the outside of the pipe

This European Standard specifies common basic principles for gas infrastructure Users of this European Standard should be aware that more detailed national standards and/or code of practice may exist in the CEN member countries This European Standard is intended to be applied in association with these national standards and/or codes of practice setting out the above-mentioned basic principles

In the event of conflicts in terms of more restrictive requirements in national legislation/regulation with the requirements of this European Standard, the national legislation/regulation takes precedence as illustrated in CEN/TR 13737 (all parts)

CEN/TR 13737 (all parts) give:

 clarification of all legislations/regulations applicable in a member state;

 if appropriate, more restrictive national requirements;

 a national contact point for the latest information

2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies

EN 1555-1, Plastics piping systems for the supply of gaseous fuels ― Polyethylene (PE) ― Part 1: General

EN 1555-2, Plastics piping systems for the supply of gaseous fuels ― Polyethylene (PE) ― Part 2: Pipes

EN 1555-3, Plastics piping systems for the supply of gaseous fuels ― Polyethylene (PE) ― Part 3: Fittings

EN 1555-4, Plastics piping systems for the supply of gaseous fuels ― Polyethylene (PE) ― Part 4: Valves

EN 1555-5, Plastics piping systems for the supply of gaseous fuels ― Polyethylene (PE) ― Part 5: Fitness for

purpose of the system

EN 12327, Gas infrastructure ― Pressure testing, commissioning and decommissioning procedures —

Functional requirements

ISO 12176-1, Plastics pipes and fittings ― Equipment for fusion jointing polyethylene systems ― Part 1: Butt

fusion

ISO 12176-2, Plastics pipes and fittings ― Equipment for fusion jointing polyethylene systems — Part 2:

Electrofusion

3 Terms, definitions, symbols and abbreviations

For the purposes of this document, the following terms, definitions, symbols and abbreviations apply

maximum pressure at which a system can be operated continuously under normal operating conditions

Note 1 to entry: Normal operating conditions are: no fault in any device or stream

butt fusion joint

method of jointing PE pipes and fittings where the two pipe ends are heated and brought together to be fused without the use of a separate fitting or filler material

Note 1 to entry: R10 and R20 series are the Renard number series conforming to ISO 3 and ISO 497

PE pipes with a peelable, contiguous thermoplastics additional layer on the outside of the pipe for the purpose

of marking and colour identification and intended to be removed for the purposes of making welds or fusing pipe and fittings

4 Design

4.1 General

The PE 80 an PE 100 products are covered by CEN/TC 155, Plastics piping systems and ducting systems

Purchasing products to CEN standards can be part of a quality programme to ensure the safety and integrity

of gas systems over their design life in service

Developments in the gas market have required new kinds of PE pipe products in addition to the original PE 80 and PE 100 materials

EXAMPLE New products include thinner wall pipes for renovation and products for trenchless techniques applications

The selection of materials, SDR series, dimensions and assembling techniques shall be the responsibility of the pipeline operator

4.2 Materials and components

PE materials and components used shall comply with EN 1555-1, EN 1555-2, EN 1555-3, EN 1555-4 and

EN 1555-5

Other components not covered by EN 1555-1, EN 1555-2, EN 1555-3, EN 1555-4 and EN 1555-5 shall conform to the relevant European Standards and International Standards or, in their absence, to national or other established standards and shall be fit for their purpose

4.3 Maximum operating pressure

4.3.1 General

The MOP should be selected on the basis of the gas infrastructure operating requirements provided that the

MOP does not exceed 10 bar and the conditions in 4.3.2 and 4.3.3 are satisfied

4.3.2 Verification of the overall service (design) coefficient

The overall service (design) coefficient C shall be calculated using the formula as given below and in Figure 1 shall be greater than or equal to 2 This coefficient C takes into consideration service conditions as well as the

properties and components of a pipeline

F

1

20

D SDR

MOP

MRS C

All pressures measured in bar

NOTE Derating factor (DF) is a coefficient used in the calculation of MOP which takes into account the influence of

operating temperature Derating factors are listed in EN 1555-5

4.3.3 Verification of the RCP criterion

The ratio of critical RCP pressure to MOP shall be greater than or equal to 1,5

The RCP criterion is the critical pressure, is dependent on pipe size and material, and shall be determined in

accordance with EN 1555-2

The critical RCP pressure is based on a temperature of 0 °C

Where pipe temperature decreases below 0 °C the PROP/MOP ratio should be recalculated in accordance with

EN 1555-5 using a value of RCP pressure determined from the minimum expected operating temperature of the pipe The value of MOP should be reduced so as to maintain the PRCP/MOP ratio at a value greater than or

equal to 1,5 See Figure 1

Key

P pressure levels;

PRCP critical rapid crack propagation pressure;

STPmax maximum strength test pressure;

STPmin minimum strength test pressure;

MIP maximum incidental pressure;

MOP maximum operating pressure

C

MRS MOP

1,5RCP

P MOP ≤

Pressure testing

1

20 1,5

MOP

RCP

0,9P

STP MIP < ≤

NOTE For RCP conditions see EN 1555-2 and EN 1555-5

Figure 1 — Pressure conditions in a PE-system

4.4 Assembly techniques

Jointing procedures can vary depending upon the PE material and sizes used

The acceptable jointing methods that shall be used are:

 fusion joints; or

 mechanical joints

Joints made between new and existing PE gas pipework shall be compatible with the materials being joined The fusion jointing techniques for the construction of PE pipelines shall be butt fusion and electrofusion Written jointing procedures, authorized by the pipeline operator, shall be available prior to the construction of a pipeline

4.5 Material properties for flow stopping by squeeze-off

When squeeze-off techniques are considered, the suitability of pipe for squeeze-off shall be established in accordance with EN 1555-2

4.6 Pipework inside buildings

The pipework element of the gas infrastructure situated in buildings shall be designed, constructed and protected so that the effects of a fire on pipework do not lead to an explosion or significant aggravation of the fire Further guidance is given in EN 12007-1

In accessible areas service lines shall be protected from external interference

5 Construction

5.1 Storage, handling and transportation

Care shall be taken during the transport, handling and storage of pipes, fittings and other components to ensure at all stages that their specified properties and conditions, which can be affected by environmental factors, are preserved and that physical damage and distortions are avoided

EXAMPLE At low temperatures, flexibility and fracture resistance are reduced

Pipes and fittings shall be inspected and those with surface defects deeper than 10 % of the nominal wall thickness shall not be used

PE pipes and fittings stored outside are subjected to UV degradation when exposed to direct daylight PE materials are stabilized to give protection for a UV radiation level of 3,5 GJ/m2 National bodies should give recommendations for allowed storage times in their countries The average radiation level for one year in European countries are given in Figure 2

Figure 2 — Isobaric curves of global radiation in gigajoules per square metre per year in Europe

Pipes shall not be used where it is considered that they have exceeded the maximum UV exposure limit, unless they have been tested to demonstrate acceptable performance in accordance with existing standards Further guidance on storage, handling and transportation of PE pipes and fittings is given in Annex A

5.2 Jointing

5.2.1 General

Personnel shall be competent in appropriate jointing methods

Jointing procedures shall be carefully followed to obtain good quality joints Cleanliness and the absence of stress are essential for reliable joints

NOTE Strong winds or cold weather can reduce the quality of the PE fusion joint when not protected

Pipes and/or fittings with fusion ends of different SDR values shall not be jointed by butt fusion

The following are minimum requirements for the assembly of fusion joints:

 cleaning of the pipe and/or fitting ends and the surface of the heated tools;

 protection against dust and other contaminating influences;

 clamping of the pipe and/or fitting ends;

 verification of the alignment and the gap between fitting and/or pipe ends;

 use of re-rounding clamps where pipe ovality exists;

 preparation of the fusion surfaces;

 marking for depth of penetration into the electrofusion sockets;

 maintenance and correct functioning of the fusion equipment and check of its compatibility with the required parameters;

 taking into account the fusion parameters as written in the jointing procedure

5.2.3 Mechanical joints

5.2.3.1 General

All mechanical joints shall be resistant to end load in accordance with EN 1555-3

All mechanical joints shall be assembled in accordance with the manufacturer’s instructions and the metallic parts of fittings shall be corrosion resistant or protected against corrosion

Satisfactory mechanical jointing procedures based upon recognized standards, manufacturers' instructions and the experience of the pipeline operator shall be utilised

In the absence of mechanical jointing procedures, ISO 10838-1 and ISO 10838-2 should be applied

Changes of direction of a PE pipeline during construction shall be achieved by means of preformed bends or elbow fittings or by the natural flexibility of the PE pipe within limits Natural flexing may be used for bend radii greater than or equal to 25 × dn mm, and for smaller radii dependant upon the SDR and material properties based on operational experience and good engineering practice

Machine bending of pipes or bending following the application of heat shall not be used

PE pipes, fittings and valves installed above ground shall be protected against mechanical interference and

Pipes shall not be overstressed by tensile forces during laying

Where the PE pipe is laid by drag, care shall be taken that the drag force is not greater than the values (in newtons) given by the formula:

( )

SDR

d force

All pressures measured in bar

Stresses caused by different temperatures between laying and operation shall be considered

Valves shall be installed so that they do not expose the PE pipe to unnecessary stress during opening and closing cycles

Material around the pipe shall be compacted so as to avoid excessive pipe ovality and shall be done layer by layer

Backfill materials around the pipe shall be selected to prevent damage to the pipe from contact with sharp edges during and after compaction

5.4 Connection to existing systems

5.4.1 Static electricity

Where there can be a release of gas in the working area, static charge accumulation shall be avoided

EXAMPLE Draping water soaked cloths of natural fibre over all pipes and fittings likely to be handled so that the cloths touch both the pipe and the ground

6 Quality control

6.1 Inspection prior to installation

The PE pipes and fittings and associated equipment shall be inspected prior to installation to confirm the following:

 conformity with 4.2, in particular verification of required gas application mark, pipe diameters, SDR, MRS

and tolerance class on basis of the pipe and fitting marking information; and

 conformity with 5.1; and

EXAMPLE 1 Limitations on outside storage have not been exceeded

EXAMPLE 2 Pipes and fittings showing obvious defects or excessive scoring are discarded, clearly identified as unsuitable and, where appropriate, returned to the source of supply

 conformity with 5.2.2 regarding the use of the equipment in accordance with relevant standards and the availability of written jointing procedures

6.2.1 Laying

Soil and trench conditions shall comply with 5.3

6.2.2 Joint integrity

Joints shall be visually inspected following procedures approved by the pipeline operator This inspection may

be carried out by the personnel engaged in jointing

EXAMPLE For butt fusion visual examination on the fusion bead, shape and geometry

Any additional inspection shall be carried out by a competent person at a frequency depending on the conditions of use The inspection shall be recorded

Destructive testing on joints made in the field can also be carried out to ensure the quality of fusion in conformity with the fusion procedure

Further information regarding inspection methods is given in Annex B

7 Pressure testing

The test pressures selected for a pipeline shall be appropriate to its MOP and shall take into account the

guidance given in Figure 1

The testing procedure(s) shall be in accordance with EN 12327

Consideration shall be given to the need for any special precautions to be taken to protect persons and property if air or inert gas is used as the test medium

For testing temperatures below 0 °C the possibility of a reduction in critical RCP pressure shall be taken into

account in the pipeline preparation and testing procedure adopted