Welding tables for plastics
Select method, material, diameter and wall thickness, and the relevant welding table is shown. The table can be read directly here or printed as a working document at the welding site.
All values on the site are indicative. The machine manufacturer's and the pipe or fitting manufacturer's instructions always apply, and joints must be made by trained personnel in accordance with current standards (e.g. DVS 2207). Holm & Holm accepts no liability for joints made on the basis of the tables here.
Data logging fields for the report (optional)
Only fill in what you want included on the printed slip. The fields change according to the selected method, and empty fields are printed as blank lines so they can be filled in by hand on site.
Butt fusion, PE (PE80/PE100), Ø110 mm
Selected: Ø110 mm · SDR 11 · wall thickness approx. 10,0 mm · standard: DVS 2207-1
Recipe for Ø110 mm · SDR 11 · e 10,0 mm
- P1 · t1: Preheating with specified pressure - pipe ends are pressed against the heating plate until the bead is approx. 1,5 mm high Welding pressure: 471 N.
- P2 · t2: Heat soaking with relieved pressure: 100 sek (1:40) · 10 x e - the pressure is reduced so the heat can penetrate the pipe wall without forcing out molten material
- t3: Changeover time – the time from when the heater plate is removed and the pipe ends are depressurised until the pipe ends are back in contact. Must take a maximum of <8 sek - and should ideally be as quick as possible, as the surface will otherwise cool down and weaken the joint.
- t4: Pressure buildup – fusion pressure is smoothly built up again to P3 without pushing out molten material. Must take a maximum of <8 sek.
- P3 · t5: Welding and cooling time under pressure – the pipe ends are held together with P3 pressure until the joint has cooled: >570 sek (9:30) Welding pressure: 471 N.
- Drag pressure P0 (the pressure just sufficient to move the machine carriage and pipe; measured for each joint) is added to all pressure settings. The diagram is schematic and not to scale.
How large may P2 be? P2 is the heat soak pressure during heating and only needs to be high enough to hold the pipe ends securely against the heater plate. P2 is therefore not a single fixed figure: the DVS 2207-1 tables specify a value depending on machine, diameter and wall thickness (often around 1 bar on the gauge, more for large wall thicknesses), while ISO 21307 describes P2 as the pressure that just maintains contact with the heater plate. Use the value from the machine's own table, and remember that drag pressure P0 is added according to the machine's pressure characteristic. If P2 becomes too high, molten material is squeezed out and the bead becomes too large.
Calculation basis: end area A = 3,142 mm² (Ø110 mm, e 10,0 mm). The welding force is the P1/P3 pressure x the area (0.15 N/mm²). The area is the ring area according to DVS 2207-1 (A = PI x s x (d - s)), which is identical to PI/4 x (D2 - (D - 2e)2).
- Clamp the pipes: clamp pipes in the machine clamping jaws - overhang = wall thickness + 1 cm, rounded up to the nearest whole cm, i.e. approx. 2 cm for the selected wall thickness (10,0 mm).
- Prepare the ends: remove dirt and grease, face both pipe ends, check flatness and ovality.
- Check and record the drag pressure (drag pressure) - the drag pressure (P0) can be entered above and added to the welding pressure.
- Set the machine: Welding force P1/P3 471 N at the selected diameter. Mirror temperature: 200-220 °C. The calculated welding pressure can be checked against the pressure characteristic curve supplied with the machine during its latest calibration.
- Contact (t1): bring the pipe ends against the heating plate at the heating-up pressure P2 until the bead is approx. 1,5 mm high. t1 is not a fixed time - the bead size determines when enough heat has penetrated. The bead dimension is an approximate figure – it is up to you to assess when the bead has the correct width.
- Heating (t2): 100 sek (1:40) · 10 x e at reduced pressure (contact), so the heat penetrates the pipe wall without squeezing out molten material.
- Changeover: remove the heating element and close the machine with the set pressure. The changeover time is the time from when pressure is released until the pipe ends are in contact again – max. 8 sek and preferably as quickly as possible, as otherwise the pipe ends will cool down and weaken the joint.
- Welding and cooling time: at least 570 sek (9:30) - earliest point in time when the pressure may be relieved. Afterwards, allow the joint to cool further before releasing the clamps, and never apply test pressure to a hot joint.
Below +5 °C ambient temperature DVS 2207-1 requires protection from the weather, uniform pipe temperature and test welds; there is no general numerical adjustment of the times.
How the cooling time is calculated: DVS 2207-1 specifies the cooling time as a band per wall thickness (e.g. 15.5-24 min for e 12-19 mm). We show the lower value of the band, i.e. the shortest time and thus the earliest point in time at which the machine pressure may be relieved. Other tables often specify a single value in the middle of or above the band, and may therefore show e.g. 17-19 min for the same pipe. After pressure relief, the joint must cool down further to ambient temperature before being lifted, loaded or pressure tested. If ISO 21307 (single low-pressure procedure) is selected, the time is calculated as e + 3 min for e under 18 mm and adjusted by approx. 1 % per °C from +20 °C.
Note: On machines with WeldControl and CNC, the machine guides you through these steps, and depending on the type it sets pressure and temperature for you from the selected parameters.
The values apply to the selected pipe ((PE (PE80/PE100), Ø110 mm, SDR 11, e 10,0 mm). The machine's and the pipe manufacturer's instructions always apply. The printout with the print button can be used as a working document on site.
Visual inspection after welding: bead width
For Ø 110 mm with wall thickness 10 mm, read off (minimum wall thickness 9 mm) an allowable bead width V of 8-11 mm, measured externally on the pipe after the completed cooling time.
| Min. wall thickness of the pipe (mm) | Allowable bead width V (mm) |
|---|---|
| 2 | 3-5 |
| 3 | 4-6 |
| 4 | 4-7 |
| 5 | 5-8 |
| 6 | 6-9 |
| 8 | 7-10 |
| 9 | 8-11 |
| 11 | 9-12 |
| 13 | 10-14 |
| 16 | 11-15 |
| 18 | 12-16 |
| 19 | 12-18 |
| 22 | 13-18 |
| 24 | 14-19 |
| 27 | 15-20 |
| 30 | 16-21 |
| 34 | 17-22 |
| 40 | 18-23 |
| 45 | 20-25 |
| 50 | 22-27 |
| 55 | 24-30 |
| 60 | 26-32 |
| 65 | 28-36 |
The table is read as minimum wall thickness: go up in the table to the nearest table value equal to or below the measured wall thickness - e.g. a measured wall thickness of 10 mm gives row 9 mm and thus a permissible bead width of 8-11 mm. When using fittings (and pipe against fitting) the tolerance is widened by +/- 1 mm. Source: Holm & Holm, "Bead width in butt welding" (holm-holm.dk).
Assess the joint visually: both beads must be even, equally wide and symmetrical all the way round, and the V-groove between the beads must lie above the weld's outer surface along the whole circumference. A notch reaching into the pipe wall itself is a sign of too high welding pressure. Discolouration (brown/yellowed bead) is a sign of too high plate temperature or too long heating.
Your row in the table
| Wall thickness e (mm) | Heating element (°C) | Bead height approx. (mm) | Heating/soak time (s) | Changeover max. (s) | Pressure build-up max. (s) | Cooling min. (min) | Welding force P1/P3 approx. (N) |
|---|---|---|---|---|---|---|---|
| 10,0 mm | 200-220 | 1,5 | 70 sek (1:10) - 120 sek (2:00) | 6-8 | 6-8 | 9,5-15,5 | 471 |
The wall thickness 10,0 mm lies in the table range 7-12 mm. The full table is shown below.
| Wall thickness e (mm) | Heating element (°C) | Bead height approx. (mm) | Heating/soak time (s) | Changeover max. (s) | Pressure build-up max. (s) | Cooling min. (min) | Welding force P1/P3 approx. (N) |
|---|---|---|---|---|---|---|---|
| up to4.5 | 200-220 | 0,5 | up to 45 | 5 | 5 | 6,5 | 114 |
| 4.5-7 | 200-220 | 1,0 | 45 sek - 70 sek (1:10) | 5-6 | 5-6 | 6,5-9,5 | 282 |
| 7-12 | 200-220 | 1,5 | 70 sek (1:10) - 120 sek (2:00) | 6-8 | 6-8 | 9,5-15,5 | 450 |
| 12-19 | 200-220 | 2,0 | 120 sek (2:00) - 190 sek (3:10) | 8-10 | 8-11 | 15,5-24 | 690 |
| 19-26 | 200-220 | 2,5 | 190 sek (3:10) - 260 sek (4:20) | 10-12 | 11-14 | 24-32 | 928 |
| 26-37 | 200-220 | 3,0 | 260 sek (4:20) - 370 sek (6:10) | 12-16 | 14-19 | 32-45 | 1,165 |
| 37-50 | 200-220 | 3,5 | 370 sek (6:10) - 500 sek (8:20) | 16-20 | 19-25 | 45-61 | 1,363 |
| 50-70 | 200-220 | 4,0 | 500 sek (8:20) - 700 sek (11:40) | 20-25 | 25-35 | 61-85 | 0 |
| 70-90 | 220 +/- 10 | 4,5 | 700 sek (11:40) - 900 sek (15:00) | 25-30 | 35 | 85-109 | 0 |
| 90-110 | 220 +/- 10 | 5,0 | 900 sek (15:00) - 1.100 sek (18:20) | 30-35 | 35 | 109-133 | 0 |
| 110-130 | 220 +/- 10 | 5,5 | 1.100 sek (18:20) - 1.300 sek (21:40) | max. 35 | 35 | 133-157 | 0 |
Pressure: bead build-up and joining P1/P3 = 0,15 +/- 0,01 N/mm2, heating P2 = 0,01 N/mm2. Source: NTG Plastik, PE100 Butt Fusion Field Guide (DVS 2207-1). Wall over 30 mm / Ø over 630: see supplement DVS 2207-1 Beiblatt 2 (220 +/- 10 °C, temperature control at 8 points). The welding force is calculated as the P1/P3 pressure multiplied by the annular area of the pipe (A = PI/4 x (D2 - (D - 2e)2)), which is the same area as DVS 2207-1's A = PI x s x (d - s), with the selected diameter and the midpoint of the range; convert to gauge pressure according to the machine's pressure characteristic. The annular area is the correct area: if you calculate PI x D x e (outside circumference) instead, the force becomes approx. 10% too high - for Ø160 SDR 11 this gives 1,101 N compared to 1,000 N at 0.15 N/mm2. The intervals are the standard's own values: the heating time is 10 x e (wall thickness in mm) in seconds, so the range applies to the whole row's wall thickness band. The precise figure for the selected wall thickness is in the recipe and in "Your row in the table" above..
Why do the numbers differ from other tables? The table shows the DVS standard ranges (e.g. heating 120–190 s for wall thickness 12–19 mm), whereas machine and supplier tables often specify a single value for their specific machine (e.g. 146 s heating and 17–24 min cooling for Ø160 SDR 11). The cooling time is displayed as the lower value of the range, as this is the earliest point at which the machine pressure can be released. The fusion force is calculated based on the actual annular area A = PI/4 x (D2 - (D-2e)2), which is identical to DVS 2207-1's A = PI x s x (d - s); if calculated as PI x D x e, the force will be approx. 10% too high. The optional welding angle increases the area by 1/cos of the cut angle – this is a geometric calculation for which DVS 2207-1 provides no formula, so it must always be balanced against the manufacturer's instructions. Drag pressure P0 is machine-dependent and added as gauge pressure. Wall thicknesses follow Holm & Holm's table according to EN 12201-2 / EN 1555-2:2025.
Applicable rules: DVS 2207-1 (butt welding), DVS 2207-4 (extrusion welding), DVS 2207-3 (hot gas welding). The tables are advisory; the pipe manufacturer's instructions and the DVS 2207 rules always apply.
Standards in the trade
Plastics welding is regulated internationally. The DVS technical rules and the EN/ISO standards are the common basis on which manufacturers' instructions and national editions build. If you want safe, documentable joints across brands, welding to DVS/EN/ISO is always a good starting point - and using the manufacturer's chart as a supplement for machine and system.
Click a short description to read more about the individual standard, and whether it is a current standard or a guidance document.
Active technical rules (DVS)The DVS 2207 seriesGerman technical rules for welding thermoplastics and the source of most welding tables in the industry, including the tables on this page.
DVS 2207-1: butt welding of PE pipes (PE80/PE100). It establishes the procedure with the four phases, heating element temperature, pressures and times, and is the basis for machine settings and data logging.
DVS 2207-3 (hot-gas welding) and DVS 2207-4 (extrusion welding): hand rod welding and mass material welding, typically for sheets, tanks and repairs.
DVS 2207-11 (PP), DVS 2207-12 (PVC-U/PVC-C) and DVS 2207-15 (PVDF): same principle for industrial materials. Material manufacturers specify the DVS 2207 series as the documented basis for their own welding tables.
DVS 2207-14 (published October 2026): heating-element fold welding of PP and PE sheets - relevant for tank and sheet work where workpieces are folded instead of butt welded.
The DVS 2207 rules are technical rules, not formal standards, but they carry the industry and are referred to directly in the manufacturers' welding procedures and in ISO work.
Active international standardsISO 12176 and ISO 21307International standards for equipment and procedures that apply across brands and countries.
ISO 12176-1: equipment and procedures for butt welding of PE pressure pipes - defines the machines' requirements and the procedure steps an approved plant must follow.
ISO 12176-2: electrofusion - requirements for fittings, control units and procedures, including barcode reading. Note: ISO 12176-2 is under revision (final draft on the way); this page follows the current edition until a new edition is published.
ISO 12176-3: equipment for heated tool socket welding (heated spigots and sockets) - the international counterpart to the DVS 2208-1 tools.
ISO 21307: butt welding of PE (American practice) - used e.g. in boundary work against American project specifications. ASTM F2620 is the corresponding American procedure guide, which American pipe manufacturers typically refer to.
If the international standard is used as the basis, the documentation can be reused across countries and machine makes, without being locked to a single manufacturer's scheme.
Active European standards (EN) with Danish editionsDS/EN 12201 and DS/EN 1555The product standards for PE pressure pipes for water and gas. The DS version is the Danish edition of the EN standard.
EN 12201: PE pressure pipe systems for water supply; EN 1555: the same for gas. Fittings follow part 3 of the series, and electrofusion fittings are covered here. The EN 12201 series was published in a new edition in 2024 (EN 12201:2024), which replaces the previous edition - the requirements for welding and parameters are unchanged for PE80/PE100.
Gas pipes: EN 1555-2:2025 (pipes - material, dimensions, wall thicknesses and tolerances) supersedes EN 1555-2:2021, which has been withdrawn. The new edition does not change the welding parameters for PE80/PE100, but wall thicknesses and tolerances must be read in the 2025 edition. The international counterpart is ISO 4437-2:2026, which supersedes ISO 4437-2:2024.
The DS/EN edition is the national Danish adoption of the EN standard: the content is identical, only the foreword and language are Danish.
Pipes with DS/EN marking can be welded according to DVS 2207-1 / ISO 12176-1 without re-testing the parameters, as long as the material is PE80/PE100.
Active technical rule (DVS)DVS 2208Operation, inspection and calibration of heated tool welding machines.
Describes how butt welding machines (mirror and carriage machines) are operated, checked and calibrated, including temperature measurement on the heating element.
DVS 2208-1 defines dimensions and types for heating tools for socket fusion welding: Type A for standard pipe ends and Type B for mechanically calibrated pipe ends – the requirement for Type B is documented in the manufacturers' tool documentation, and the tools are available in both types.
Documented joints require machines that are checked and calibrated according to DVS 2208; modern control units store the parameters automatically and can provide a welding record.
Active certification and attestation scheme (INSTA)INSTA-CERT (calibration and verification)Inter-Nordic attestation scheme for periodic verification and calibration of butt fusion welding machines.
INSTA-CERT is an inter-Nordic attestation scheme for periodic verification and calibration of butt fusion welding machines. The machine is typically verified every 12 months by a manufacturer-approved and accredited calibration partner, and the certificate can be presented upon inspection.
If the client authority requires the certificate, it must be provided. Documentation of calibration according to ISO 12176-1 or DVS 2208 is the standard basis in most projects.
Active European standards (EN) with Danish editionsDS/EN 13244 and DS/EN 12666The product standards for PE pipes for drainage, sewer and other non-pressure applications.
EN 13244: PE pipes for drainage, sewerage and non-pressure sewer systems; EN 12666: PE piping systems for non-pressure drainage and sewerage. The Danish DS/EN editions are the national adoptions.
PE drainage and sewer pipes are welded using the same methods and the same DVS 2207-1 table basis as pressure pipes; pipe suppliers specify the EN standards together with DVS-based welding instructions.
Note that wall thicknesses and the SDR range for drainage pipes can differ from pressure pipes: always check the pipe's own standard marking before using values from the pressure pipe tables.
Active testing standardsTesting of joints: ISO 13953, ISO 13954 and EN 12814Mechanical testing standards for documenting the quality of the joints.
ISO 13953: tensile testing of butt welded PE joints; ISO 13954: peel testing of electrofusion and butt welded joints.
The EN 12814 series: tensile testing of welded thermoplastic joints in general - also used for hot-air and extrusion joints and for acceptance testing in industry.
Independent laboratories and pipe manufacturers use these tests for type approval and quality control; if there is doubt whether a weld has been correctly executed, testing according to these standards is the documentable proof.
Active technical rules (DVGW, Germany)DVGW W 400-2 and the DVGW rulesGerman gas/water rules for making and testing welds - often cited in supplier instructions alongside DVS.
DVGW W 400-2 and G 400-2 describe the execution of plastic welds and pressure tests on water and gas pipelines; the rules are referred to directly in, for example, squeeze-off and pressure test procedures.
DVGW working sheets require documented personnel qualification and calibrated equipment, and they specify the pressure test procedure which many Danish contractors carry forward in their specifications.
Active national standard (NEN)NEN 3650 (The Netherlands)Dutch standard for piping systems for gas and water - specifies supplementary requirements for execution, testing and documentation beyond the EN standards.
NEN 3650 is the national standard for gas and water pipelines in the Netherlands and consists of a number of parts covering, among other things, the construction, welding, testing and operation of PE pipelines.
In terms of content, a NEN-EN 12201 is identical to EN 12201; the stricter requirements stem from NEN 3650 itself, which Dutch client authorities typically write directly into contracts together with requirements for welding procedures, personnel qualification and test pressure.
Active Swedish code of practice (Svensk Byggtjänst)Anläggnings AMA (Sweden)Swedish specification and practice reference work for civil engineering works - specifies requirements for qualification, documentation and inspection for e.g. PE welding in Swedish tenders.
Anläggnings AMA (current edition Anläggning 23) is not a welding standard, but the general industry reference work according to which Swedish client authorities in practice specify their services - including requirements for welding, testing, logging and documentation on PE pipelines.
Swedish projects typically refer to the SS-EN standards for pipes and fittings combined with Anläggnings AMA for execution, so that welding is carried out according to DVS 2207-1/ISO 12176 as usual.
Active national adoptions of the EN standardsSS-EN, NS-EN, SFS-EN and UNI EN (national EN adoptions)Swedish, Norwegian, Finnish and Italian editions of the European standards - the content is identical to EN, with only the language and foreword nationalised.
SS-EN (Sweden), NS-EN (Norway), SFS-EN (Finland) and UNI EN (Italy) are the national adoptions of EN 12201, EN 1555 and EN 13244 - in the same way as DS/EN in Denmark.
The prefix does not change the requirements: a pipe or fitting joint welded according to DVS 2207-1/ISO 12176-1 meets the requirements in all versions, provided the material is PE80/PE100. National supplementary regulations (e.g. Anläggnings AMA in Sweden) may, however, impose additional requirements for execution and documentation.
Active technical rule (DVS)DVS 2205 (vessels and apparatus)The basis for welding in tank, vessel and apparatus construction in thermoplastics.
DVS 2205 covers materials and design of containers and apparatus in thermoplastics; extrusion and hot-air welding of sheets and tanks is typically documented against this basis together with DVS 2207-3/-4.
Extruder manufacturers specify parameters according to DVS 2207-4 and refer to industrial applications where DVS 2205 defines the requirements for the joints.
Current EU directive (law, not a standard)2006/42/EC (Machinery Directive)The EU Machinery Directive: requirements for machine safety, CE marking and the declaration of conformity - also for butt fusion and electrofusion machines.
The Machinery Directive 2006/42/EC is binding legislation, not a standard: a machine may first be sold and taken into use in the EU when it meets the essential requirements in Annex I, is CE-marked and is supplied with a declaration of conformity and an instruction manual in the user's language.
It also covers plastic welding machines: butt welding machines, electrofusion welders, extruders and hot-gas tools must have documented risk assessments and protective measures.
Note: the Machinery Directive is replaced by the Machinery Regulation (EU) 2023/1230, which applies from 20 January 2027 - the requirements largely carry over, but equipment is documented according to the regulation from then on.
Harmonised standards (e.g. EN 60204-1 for electrical equipment on machines) are used as a practical key to meeting the directive's requirements - the directive says "what", the standards say "how".
Practice based on ISO 12176 and DVS 2207-1Traceability and ISO-compatible data loggingISO-compatible traceability: every weld is documented with machine, parameters, operator and date in a defined data format.
ISO 12176-1 and -2 define data records for butt welding and electrofusion, and DVS 2207-1 requires the parameters to be recorded. "ISO-compatible" traceability means the welding record follows these defined fields - not the manufacturer's closed format.
A full welding record typically contains machine and tool ID, pipe data (material, diameter, SDR), target parameters (temperature, pressure, times) as well as the results per phase, operator and timestamp.
The format makes the records readable across machine makes: files from one control unit can be imported and quality-assessed with other software, and the entire pipe section can be documented as a whole.
In excavation and construction work, traceability is often a requirement from the client; welding records in the ISO/DVS format are documentation that can be verified independently of the machine manufacturer.
The ISO 12176 series also contains a part on coding and traceability (ISO 12176-4). Check the part number and edition in the standards catalogue before referencing it in a contract.
Active regulations and standards for personnel qualificationDVS 2212-1 and EN 13067 (welder qualification)Documentation proving that the individual welder is trained and tested in the specific method being used.
DVS 2212-1: training and testing of plastics welders. The welder is tested in the methods carried out in practice, and the qualification must be renewed at regular intervals.
EN 13067: European standard for the qualification of plastics welding personnel. Used when contractors need to document welders on projects outside Germany and Denmark.
In practice, asset owners request both machine calibration (ISO 12176-1/DVS 2208) and welder qualification. The welding log should therefore show who executed the joint and what qualification that person held.
Active international product standardsISO 4427 and ISO 4437International standards for PE pressure pipes for water and gas – global equivalents to EN 12201 and EN 1555.
ISO 4427 covers PE piping systems for water supply, ISO 4437 the same for gas. The parts include pipes, fittings and system fitness for purpose. ISO 4437-2:2026 (pipes) was published in October 2026 and supersedes ISO 4437-2:2024.
The standards are used in projects outside the EU and in supply chains where pipes and fittings come from multiple countries.
The welding parameters do not change: PE80/PE100 is still welded according to DVS 2207-1 or ISO 12176-1/ISO 21307, while ISO 4427/ISO 4437 specifies what the pipe must withstand.
Active international standardsISO 9080, ISO 12162 and ISO 1167 (material classification)The basis for designating a pipe PE 80 or PE 100: long-term strength, classification and pressure testing.
ISO 9080: extrapolation of long-term data for pipes to determine durability beyond the measured period.
ISO 12162: classification of thermoplastic materials based on MRS (minimum required strength). PE 100 means MRS 10 MPa, PE 80 means MRS 8 MPa.
ISO 1167: internal pressure testing, documenting that pipes and joints withstand the calculated pressure over time. These are the data on which the SDR and PN designations are based.
Used when a customer asks why PE 100 can withstand higher loads than PE 80 at the same wall thickness.
Active European standards (EN)EN 12201-5 and EN 1555-5 (fitness for purpose)Documentation for the complete system – not just the individual joint.
Part 5 of the series describes fitness for purpose: how pipes, fittings, joints and operation are documented as a complete system for water systems (EN 12201-5) and gas systems (EN 1555-5).
For the contractor, this means that the welding log, pressure test and calibration are linked as a single documentation package – not as detached attachments.
Active technical rule (DVS)DVS 2202-1 (evaluation of welded joints)The material basis for the evaluation: which defects in and around the weld seam are acceptable, and which require re-welding.
DVS 2202-1 describes imperfections in welded joints in thermoplastics and serves as the common framework of reference for how a finished joint is evaluated: joint geometry and bead formation, high-low misalignment and angular deviation, voids and inclusions, lack of fusion as well as surface defects in and adjacent to the joint.
The rule is used as a defect catalogue on site: it helps distinguish between cosmetic conditions that do not affect strength and defects that mean the joint must be cut out and re-welded.
DVS 2202-1 is the evaluation - not the testing method. In case of doubt, it is supplemented by destructive testing in accordance with the DVS 2203 series or ISO 13953/13954/13955, and by pressure testing of the completed pipeline.
Used when a joint must be accepted or rejected with reference to a rule rather than a gut feeling, e.g. during receiving inspection or when the client requires documented evaluation.
Check the edition and part number in the standards catalogue before referencing the rule in a contract - the DVS series is updated continuously.
Active technical rule (DVS)DVS 2203 (testing of welded joints)The test basis: tensile, bend and peel testing of welded joints, used for procedure testing and inspection.
The DVS 2203 series describes mechanical testing of welded joints in thermoplastics. The tests demonstrate whether the joint has the expected strength and a ductile behaviour rather than a brittle fracture surface.
Tensile testing shows tensile strength and fracture appearance; bend testing shows whether there are lack of fusion defects or brittle zones in the joint; peel testing is used in particular on electrofusion socket joints and on thin-walled components.
Testing is used in two contexts in practice: as procedure qualification testing when a welding procedure or a new machine is to be approved, and as spot/receiving inspection on the finished work where a test specimen is cut out or a reference joint is welded.
The result is documented together with the welding log: parameters, type of test, fracture appearance and evaluation. The log shows what was welded, the testing shows what the joint holds.
Testing does not change the welding parameters - it checks them. The parameters continue to come from the DVS 2207 series or the manufacturer's table.
Active testing standardsISO 13955 and ISO 13956 (supplementary testing)Multiple test methods for documenting joints, beyond ISO 13953 and ISO 13954.
ISO 13955: bend testing of welded PE joints, showing whether the joint has a smooth transition without brittle zones.
ISO 13956: testing of welded thermoplastic joints, supplementing other tests when a project requires multiple forms of documentation.
Always check designation and edition in the standards catalogue, as the series is updated continuously.
Active European standard (EN)EN 1610 (testing of drains and sewers)Testing of non-pressure drain and sewer pipelines once the joints are completed.
EN 1610 specifies testing of drains and sewers with water or air before the pipeline is commissioned, supplementing DS/EN 805, which applies to pressure pipes for water supply.
The testing is the client's documentation that the joints are leak-tight; the result should be filed with the welding record.
Active industry requirements (Norway and United Kingdom)NORSOK M-621 and WIS 4-32-08/4-32-14 (industry requirements)Special requirements from the offshore and British water sectors when required by the project.
NORSOK M-621 specifies requirements for polymers and welding on Norwegian offshore installations, typically with stricter requirements for material selection and documentation.
WIS 4-32-08 and WIS 4-32-14 are the UK water industry specifications for PE pipes and welded joints; they are used in tenders in the UK alongside the EN standards.
The requirements do not change the welding procedure, but typically impose additional requirements for testing, traceability and personnel.
Not a standard - informative documentDS/INF 70-6An informative guidance document from Danish Standards, never part of the standards collection.
INF publications are informative: they describe practice and experience, but they are not standards and do not apply as requirements.
DS/INF 70-6 is therefore not a document to weld to; the actual basis for butt welding of PE is DVS 2207-1 and ISO 12176-1.
The document is mentioned here because it features in the Danish debate on calibration of welding machines - but its status is guidance, not a standard.
National standards in selected countries
EN standards are identical in content across all EU/EEA countries, but are published nationally with a prefix. The table shows national editions and selected national regulations in the countries covered by our language versions. Always check the applicable national edition for the specific project.
| Country | National prefix | Typical standards and regulations |
|---|---|---|
| Denmark | DS | DS/EN 12201, DS/EN 1555, DS/EN 13244, DS/INF 70-6 |
| Germany | DIN | DIN EN 12201, DIN EN 1555, DVS 2207, DVGW W 400-2 and G 400-2, DVGW GW 332 |
| Sweden | SS | SS-EN 12201, SS-EN 1555, SS-EN 13244, Anläggnings AMA (code of practice) |
| Norway | NS | NS-EN 12201, NS-EN 1555, NS-EN 13244 |
| Finland | SFS | SFS-EN 12201, SFS-EN 1555, SFS-EN 13244 |
| Netherlands | NEN | NEN-EN 12201, NEN-EN 1555, NEN 3650 (pipeline systems for gas and water) |
| Italy | UNI | UNI EN 12201, UNI EN 1555, UNI EN 13244 |
| Spain | UNE | UNE-EN 12201, UNE-EN 1555, UNE-EN 13244 |
| United Kingdom | BS | BS EN 12201, BS EN 1555, WIS/IGN (water industry specifications) |
| Ukraine | ДСТУ | ДСТУ EN 12201, ДСТУ EN 1555 |
The prefix does not change the requirements: an SS-EN 12201 is in terms of content the same EN standard as DS/EN 12201. However, national supplementary regulations (e.g. DVGW in Germany and NEN 3650 in the Netherlands) may impose stricter requirements for execution and testing.
Bending radii for PE pipes and welding near bends
The bending radii below are indicative minimum values for cold bending of PE pipes without internal pressure. The colder the pipe, the stiffer the material becomes, and the larger the radius must be. The pipe manufacturer's own instructions always apply.
| Temperature | Recommended minimum bending radius (d = pipe outside diameter) |
|---|---|
| +20 °C and warmer | approx. 20 × d |
| +10 °C | approx. 25 × d |
| 0 °C | approx. 30-50 × d |
| Below 0 °C | at least 50 × d |
The values are indicative industry guidelines, not standard specifications. Never bend a weld while it is still cooling, and follow the pipe manufacturer's table for the specific pipe type and SDR class.
Precautions when welding in or near bent pipe sections
- Always weld on a straight pipe section and maintain the distance from the bend specified by the pipe manufacturer - typically several times the pipe diameter.
- Never weld on a section that is under bending stress: the stress can strain the joint while it cools.
- Only realign or bend once the joint has completely cooled down; DVS 2207-1 permits only slight correction within the allowable bending radius range.
- Check the ovality after the pipe has been bent or straightened before electrofusion welding: an oval pipe results in incorrect annular gap and a weak weld.
Weather and environmental conditions: rain, moisture, wind and cold
The times and temperatures in the tables only apply when conditions around the joint are controlled. The DVS 2207 series assumes that components, machine and welding zone are protected from rain, snow, draughts and direct sunlight, and that actual conditions can be documented. Ambient temperature and wind limits follow the applicable edition of the standard and the manufacturer's instructions – if conditions cannot be controlled, work must be postponed or moved indoors.
| Conditions | Effect on the joint | How to protect |
|---|---|---|
| Rain and driving rain | Water in the welding zone vaporises in the melt, causing porosity and a cold weld – particularly critical in electrofusion welding. | Do not weld in rain or snow. Use a tent or shelter, dry pipe ends, fittings and tools, and drain water out of pre-insulated pipes and couplers. |
| Moisture and condensation | Cold pipes in a warm tent or in sunlight form condensation within minutes. Moisture on the heating element causes poor heat transfer. | Store pipes dry and covered, lift them clear of the ground, cap the ends, and allow cold components to acclimatise. Wipe clean immediately prior to heating. |
| Wind and draught | Wind cools the heating element and pipe ends unevenly, rendering times incorrect, and blows dust and sand into the melt. | Provide windbreaks against the prevailing wind direction, do not point an open pipe end into the wind, and shield the heating element when moving it. |
| Cold and frost | PE becomes stiffer and more brittle, components are more difficult to round, hydraulic oil and batteries become sluggish, and snow in clamps and the welding zone ruins the joint. | Allow the machine to warm up, keep components and tools free of snow and ice, handle pipes with care, and do not unload the joint until the specified cooling time has elapsed. |
| Heat and direct sunlight | A pipe lying half in the sun becomes hot on one side, resulting in ovality and an uneven melt front. | Shield components and machine from sunlight, do not place pipes intended for welding in the sun, and relocate work if the ambient temperature exceeds what the procedure permits. |
Set up the site before work begins
- Select a tent or tarpaulin that provides both shelter and dryness, and ensure that water cannot run in across the base. The ground must be level and load-bearing so the machine does not sink or slip.
- Ventilation is essential: PVC-U releases hydrochloric acid and requires extraction, and a generator must never run in an enclosed tent due to carbon monoxide.
- Protect power supply and cabling against water, and use task lighting so that the bead, melt front and dirt can be seen inside the tent and during the winter months.
- Enter air temperature, weather and protective measures in the log fields so the joint can be documented - even if the work was interrupted by weather and resumed.
The complete guide is in the article Weather and environmental conditions: rain, moisture, wind and cold during plastics welding.