---

Dimensions in millimetres

Table 1 (2 of 3)

Tablei (3of3)

Dimensions in millimetres

^a " /" = and; В = Bend test (f: face ; r: root; s: side (for thick materials)) Pc = Peel test (crush test); V = Visual examination; Pd = Peel test (decohesion test); T = Tensile test; Vis = Visual examination of longitudinal sections

^ь V = V preparation

X = double V preparation

1 = fillet weld

][ - butt weld

.f. = saddle

I - socket

^c Welding by machine only

Dimensions in millimetres

Table 2 — Lining membranes details of tests (1 of 2)

Table 2 (2 of 2)

⁴" /" = and; Pt= Peel test (T-peel test); V = Visual examination

6. D

   Dimensions in millimetres

   uty of Plastics Welding Examiner and invigilator

The test shall be supervised by a PWE or invigilator and shall be marked and signed by a PWE.

The PWE shall be responsible for sending the test pieces to the qualified test house.

The PWE shall not examine any candidate trained by himself. The PWE shall reach his professional decisions independently.

The PWE shall check the test house qualification and, where applicable, the training centre.

6. Range of qualification

The designation of a plastics welder's test shall be formed according to the group and sub-group and the range of qualification (see Table 1 or Table 2). The range of validity of qualification shall be shown on the certificate.

6. Welding of test piece

   1. Difficulties and corrections whilst welding the test piece

If difficulties arise during the practical test that are not caused by the welder, a test piece on which welding has been started may be replaced after qualification by the PWE or invigilator.

Errors made or occurring during the hot gas or extrusion welding may be repaired only after permission has been given by the PWE or invigilator.

Before welding, the PWE or invigilator shall check the identity of candidate, the suitability of the materials, WPS, machines and equipment. The test piece shall be identified with the number or mark of the PWE or invigilator and the welder.

The PWE or invigilator shall supervise the welding of the test piece.

The welder shall complete the welding record sheet (see proposal given in Annex A) controlled and witnessed by the PWE or invigilator.

The PWE or invigilator shall stop the test if the welding conditions are not in compliance with the WPS or the welder does not have the skill required to obtain a satisfactory result.

The PWE shall visually check the test piece after completion by the welder.

The test piece shall be as required in Table 1 or Table 2.

6. Test piece and test specimens, shapes and dimensions

The dimensions of the test piece and the number of test specimens to be cut from the test piece shall be those specified for the particular test sub-groups (see Figures 1 to 9).

The shapes, dimensions and conditioning of the test specimens are specified in the relevant test standards.

Cutting the test specimens shall be carried out without significant damage to the welds and their heat affected zones.

Tests, other than the initial visual examination, shall be carried out by a qualified test house agreed upon by the parties involved. The test house shall be responsible for cutting the test specimen and carrying out the tests. The standards against which the test house is qualified shall be referenced.

Minimum dimensions in millimetres

Key

1. discard

2. 6 bend test specimens cut as directed by the PWE

1. — Test piece for a butt weld on sheet (for bend test specimens)

Key

1 4 test specimens, 1 in each location (x_b x₂, Уі, y₂) cut as directed by the PWE

I S 350 or 2 cf_n whichever is longer

— Test piece for a butt weld on pipe (for bend or tensile test specimens)Minimum dimensions in millimetres

Key

1. discard

2. 5 tensile test specimens cut as directed by the PWE

3. 3 tensile test specimens (for reference) cut as directed by the PWE

Figure 3 —Test piece for a butt weld on sheet (for tensile test specimens)

Key

1. socket

2. pipe

For subgroups 1.5, 3.7, I > d_n

For subgroups 1.4, 2.6, 2.7, 3.6, 3.9, 4.4, I > 5 d_n

Figure 4 — Test piece for a socket weld

Minimum dimensions in millimetres

Figure 5 — Test piece for a saddle weld

Minimum dimensions in millimetres

1 welding zone

b)

Figure 6 — Test piece for lining membranes - Lap seam without testing channel

Minimum dimensions in millimetres

a)

Key 1 welding zone

a the dimensions are dictated by the machine, WPS employed.

b)

Figure 7 — Test piece for lining membranes - Lap seam with testing channel

Minimum dimensions in millimetres

Key

1 welding zone

a the dimensions are dictated by the WPS employed

b)

Figure 8 — Test piece for lining membranes - Lap seam extrusion welded

10. Evaluation and acceptance criteria of test piece(s) and test specimens

    1. General

The PWE evaluates the test piece, the test specimens and the results produced by the test house. The evaluation of the test piece and the test specimens is divided into two sections, visual and destructive.

Visual examination is described in 10.2.

Destructive tests are described in 10.3.

The following designation for the test evaluation applies:

— c: conform;

—- nc: not conform.

The results and the evaluation shall be noted on the relevant evaluation record form (see proposal given in the informative Annex C).

Visual evaluation applies to all stages of practical and destructive tests.

The visual examination shall be carried out in accordance with EN 13100-1 and any relevant imperfections observed, as defined in EN 14728 (where applicable), shall be recorded.

The test piece shall comply with the WPS.

The PWE or invigilator, after confirming that the test pieces conform to the visual examination carried out in accordance with 10.2, shall submit the test pieces to the test house for tests described in Clause 9 and Table 1 or Table 2.

The test house shall be operating in compliance with EN ISO/IEC 17025.

Results produced (test record) and tested specimens shall be sent by the test house to the PWE for verification.

Storage or disposal of the test piece or test specimens shall be as instructed by the PWE.

The bend test shall be carried out in accordance with EN 12814-1, except for the number of specimens tested and that the test specimen width shall be 20 mm in all cases.

Where Table 1 requires "B f+ r” half of the test specimens shall be tested as В f and half as В r.

The minimum requirements for each test specimen shall equal or exceed the values given in EN 12814-8. If the criterion for failure used is that a maximum load is reached, then bend angles or ram displacements below the minimum values shall be considered acceptable providing that they are not less than the values achieved by test specimens cut from the parent sheet.

Should one test specimen fail to meet the required minimum bending angle, two additional test specimens shall be taken, from the same test piece and re-tested under identical conditions. If the bending angle thus obtained fails to give the required value, the test does not conform.

The peel test shall be carried out in accordance with EN 12814-4.

The peel test method for each material and sub-group given in Tables 1 and 2 are shown in Table 3.

Table 3 — Peel test method

For the decohesion test, rupture in the brittle mode shall not exceed 25 % of the axial length of the weld.

For the crush test, the fracture in the weld shall not extend beyond the second turn of wire of an electrofusion fitting. For heated tool welds any resulting fracture shall not occur between the pipe and fitting.

For the T-peel test, all failures, except for an AD-WLD break (Figure 9), shall be in the parent material.

Figure 9 — AD-WLD break

The tensile test shall be carried out in accordance with EN 12814-2 except for the number of test specimens.

For PE pipes covering sub-groups 3.4 and 3.5 in Table 1, test specimens conforming to Annex В of EN 12814-2:2000 shall be used. For group 5 materials, type 2 test specimens shall be used.

Depending on the test specimen used, the purpose of the tensile test is slightly different. For test specimens conforming to Annex В of EN 12814-2:2000, rupture in the brittle mode (as shown in ISO 13953) of any of the test specimens does not conform.

For test specimens conforming to a type 2 geometry the purpose of the test is to determine the short term tensile welding factor, fs. The short term tensile welding factor shall be determined based on:

• five welded and three unwelded reference test specimens for Subgroup 5.1;

• four welded and four unwelded reference test specimens for Subgroup 5.2 in the same location.

The values for the short term tensile welding factor fis are given in Table 4.

For multiple destructive evaluation, where the source, grade and direction of extrusion of the parent material is exactly the same as the welded test specimen, then at the discretion of the PWE there shall be no need for the reference tests to be repeated.

Should one test specimen fail to meet the required short term tensile welding factor /s, two additional test specimens shall be taken, from the same test piece and re-tested under identical conditions. If the short term tensile welding factor fe thus obtained fails to give the required value, the test does not conform.