prEN 12814-2

• Abstract:

  This document specifies the dimensions, the method of sampling, the preparation of the test specimens and the conditions for performing the tensile test in order to determine the short-term tensile welding factor.; A tensile test can be used in conjunction with other tests (e.g. bend, tensile creep, macro) to assess the performance of welded assemblies, made from thermoplastics materials.; The test is applicable to welded semi-finished products made from thermoplastics materials filled or unfilled, but not reinforced, irrespective of the welding process used.

• Status: Not Published
• Publication Date: 02-Sep-2027
• ICS: 25.160.40 - Welded joints and welds
• Technical Committee: CEN/TC 249 - Plastics
• Drafting Committee: CEN/TC 249/WG 16 - Welding of thermoplastics
• Current Stage: 4060 - Closure of enquiry - Enquiry
• Start Date: 13-Aug-2026
• Due Date: 14-Aug-2026
• Completion Date: 13-Aug-2026
• Ref Project: oSIST prEN 12814-2:2026 - Testing of welded joints of thermoplastics semi-finished products - Part 2: Tensile test

• Revises: EN 12814-2:2021 - Testing of welded joints of thermoplastics semi-finished products - Part 2: Tensile test
• Effective Date: 02-Jul-2025

prEN 12814-2 is a draft European Standard from CEN for testing welded joints of thermoplastics semi-finished products by tensile test. It specifies how to sample, prepare and test welded and unwelded specimens to determine the short-term tensile welding factor for filled or unfilled, non-reinforced thermoplastics, regardless of welding process.

What does prEN 12814-2 specify?

prEN 12814-2 specifies the dimensions of the test specimens, how to take them from welded assemblies, how to prepare them, and the conditions for carrying out the tensile test. It is organized into 11 clauses plus 2 informative annexes.

The tensile test is used on its own or alongside bend, tensile creep and macro tests when a user needs to assess welded assemblies in practice. That makes the document useful both for routine quality control and for comparing welding performance across materials or processes.

Annex	What it covers
Annex A	Tensile test specimen for overlap joints
Annex B	Recommended test speeds for some thermoplastics materials

What are the key requirements of prEN 12814-2?

Sampling and specimen preparation

prEN 12814-2 requires welded and unwelded specimens to be cut perpendicular to the weld at least eight hours after welding. Each specimen must be marked so its original position in the test piece can be traced, and no heat treatment or mechanical straightening may be applied.

In practice, this keeps the test tied to the actual welded condition and avoids changes that could hide defects or alter strength.

Specimen geometry and cutting

prEN 12814-2 gives two main specimen types in Clause 6, with dimensions set out in Tables 1 and 2 and Figures 1 and 2. For small tubes with nominal outside diameter Dn below 20 mm, the whole tube is tested, with a minimum clamp distance of 200 mm.

Beads are kept or removed according to how the joint will be used in service. The document also sets tolerances for the test specimen width and calibrated length, and Annex A gives a separate geometry for overlap joints.

Condition of the cut specimen

prEN 12814-2 requires the cut to produce parallel sides and to minimize heating during cutting. The cut must not create notches, and the weld must then be visually examined in line with EN 13100-1 and recorded.

That matters because damage from cutting can shift failure away from the weld and distort the result.

Test conditions and speed

prEN 12814-2 requires conditioning at 23 °C ± 2 °C and, unless otherwise specified, testing at room temperature within the same range. Test speeds must follow EN ISO 527-1, and the chosen speed should make the test finish in about one minute.

At least five welded and five unwelded specimens are tested for each test piece, with the same geometry, same speed and same clamp distance. Annex B gives example speeds for some thermoplastics materials.

Calculation and failure rules

prEN 12814-2 determines the short-term tensile welding factor from the mean fracture stresses of welded and unwelded specimens. If a specimen yields before fracture, yield stress is used instead of fracture stress.

No specimen may be discarded unless the failure occurred in the clamps. The clause also defines when a failure counts as a clamp failure for type 1, type 2 and whole-tube specimens, and it allows the unwelded specimens to be omitted when all welded specimens fail or yield outside the weld but within the calibrated length.

Test report

prEN 12814-2 requires the report to identify the test piece, specimen type, weld type, dimensions, temperatures, crosshead speed, individual force and stress values, calculated averages, the short-term tensile welding factor, deviations, and the responsible person.

That gives buyers, labs and auditors the traceability needed to compare results later.

What terms does prEN 12814-2 define?

• f_s - the short-term tensile welding factor, used to compare welded and unwelded tensile performance.
• σ_w - the mean stress of the welded specimens used in calculating f_s.
• σ_r - the mean stress of the unwelded reference specimens used in calculating f_s.
• Dn - the nominal outside diameter of a tube, used to select specimen dimensions and clamp spacing.
• a - the nominal thickness of the test piece.
• b - the width of the calibrated and parallel length of the specimen.
• L_o - the calibrated and parallel length, which is the key test length for valid failure location.
• r - the radius of the shoulder of the specimen.

Who uses prEN 12814-2?

prEN 12814-2 is used by testing laboratories, welders, fabricators, and quality engineers working with thermoplastics assemblies. It is relevant in qualification work, process checks, incoming or production control, and investigations of weld performance on pipes, fittings, sheets and other semi-finished products.

It is also useful to buyers and specifiers who need a repeatable tensile test method for welded thermoplastics joints.

What changed in prEN 12814-2 from the previous edition?

prEN 12814-2 supersedes EN 12814-2:2021. The stated technical changes are revised minimum test specimen lengths and deletion of Annex C, which covered a notched tensile test specimen.

Which standards are used with prEN 12814-2?

• EN ISO 291 - gives the standard atmosphere for conditioning and testing plastics specimens.
• EN 13100-1 - provides the visual examination method for welded joints before testing.
• EN ISO 527-1 - supplies the general principles for tensile testing, including test speed requirements.
• ISO 5893 - specifies the tensile test equipment requirements, including constant-rate-of-traverse machines.
• EN 13067 - is cited as a related qualification standard for welders.
• EN 12814-7 - is cited as a related tensile test method using waisted test specimens.
• ISO 13953 - is cited as a related tensile test method for butt-fused PE joints.

What does the prEN 12814-2 document contain?

The document contains the scope, normative references, symbols and abbreviated terms, the test principle, sampling procedure, specimen dimensions, cutting rules, mechanical testing conditions, equipment requirements, the calculation of the short-term tensile welding factor, and the test report content.

It also includes Figures 1 and 2 for the main specimen forms, Figure A.1 for overlap joints, Tables 1 and 2 for specimen dimensions, Table A.1 for overlap-joint dimensions, and Table B.1 with example test speeds for selected thermoplastics. Those parts are the practical basis for laboratory setup, execution and reporting.

SLOVENSKI STANDARD
01-julij-2026
Preskušanje zvarjenih spojev plastomernih polizdelkov - 2. del: Natezni preskus
Testing of welded joints of thermoplastics semi-finished products - Part 2: Tensile test
Prüfen von Schweißverbindungen an Halbzeugen aus thermoplastischen Kunststoffen -
Teil 2: Zugversuch
Essais des assemblages soudés sur produits semi-finis en thermoplastiques - Partie 2 :
Essai de traction
Ta slovenski standard je istoveten z: prEN 12814-2
ICS:
25.160.40 Varjeni spoji in vari Welded joints and welds
83.080.01 Polimerni materiali na Plastics in general
splošno
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2026
ICS 25.160.40 Will supersede EN 12814-2:2021
English Version
Testing of welded joints of thermoplastics semi-finished
products - Part 2: Tensile test
Essais des assemblages soudés sur produits semi-finis Prüfen von Schweißverbindungen an Halbzeugen aus
en thermoplastiques - Partie 2 : Essai de traction thermoplastischen Kunststoffen - Teil 2: Zugversuch
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 249.
If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 12814-2:2026 E
worldwide for CEN national Members.

prEN 12814 2:2026
Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms, definitions, symbols and abbreviated terms . 4
3.1 Terms and definitions . 4
3.2 Symbols and abbreviated terms . 4
4 Principle of the test . 5
5 Sampling procedures . 5
6 Dimensions of test specimens . 5
7 Cutting of test specimens . 7
8 Mechanical testing . 7
9 Test equipment . 8
10 Determination of the short-term tensile welding factor . 8
11 Test report . 8
Annex A (informative) Tensile test specimen for overlap joints . 10
Annex B (informative) Recommended test speeds for some thermoplastics materials . 11
Bibliography . 12
European foreword
This document (prEN 12814-2:2026) has been prepared by Technical Committee CEN/TC 249 “Plastics”,
the secretariat of which is held by SIS.
This document is currently submitted to the CEN enquiry.
This document supersedes EN 12814-2:2021.
In comparison with the previous edition, the following technical modifications have been made:
— the minimum test specimen lengths have been revised;
— Annex C (notched tensile test specimen) has been deleted.
prEN 12814 2:2026
1 Scope
This document specifies the dimensions, the method of sampling, the preparation of the test specimens and
the conditions for performing the tensile test in order to determine the short-term tensile welding factor.
A tensile test can be used in conjunction with other tests (e.g. bend, tensile creep, macro) to assess the
performance of welded assemblies, made from thermoplastics materials.
The test is applicable to welded semi-finished products made from thermoplastics materials filled or
unfilled, but not reinforced, irrespective of the welding process used.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
EN ISO 291, Plastics — Standard atmospheres for conditioning and testing(ISO 291)
EN 13100-1, Non destructive testing of welded joints of thermoplastics semi-finished products — Part 1:
Visual examination
EN ISO 527-1, Plastics — Determination of tensile properties - Part 1: General principles (ISO 527-1)
ISO 5893, Rubber and plastics test equipment — Tensile, flexural and compression types (constant rate of
traverse) — Specification
3 Terms, definitions, symbols and abbreviated terms
3.1 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at https://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.2 Symbols and abbreviated terms
For the purposes of this document, the following symbols and abbreviated terms apply:
a minimum measured thickness of the test specimen within mm
calibrated and parallel length
a nominal thickness of the test piece mm
n
b width of calibrated and parallel length of the test specimen mm
b width of shoulder of the test specimen mm
nominal outside diameter of the tube mm
Dn
F the value of force of the unwelded test specimens taken from the N
r
same test piece, used in the calculation of f
s
f the short-term tensile welding factor None
s
F the value of force of the welded test specimen used in the N
w
calculation of f
s
L total length of t
...