Erstellungsdatum: 04.11.

1999
Letzte Änderung: 13.02.2002
File-Name: C:\Kunden\DVS\Richt.+Merkbl\2207\englisch\e2207t5.fm

Directive D
DVS – DEUTSCHER VERBAND Welding of Thermoplastics –
DVS 2207-5
FÜR SCHWEISSEN UND Welding of PE Casing Pipes, V
VERWANDTE VERFAHREN E.V. Tubes and Tubular Components (Februar 1993) S 

Contents: – Permanent mechanical joint under thermal load resulting from

the temperature of the medium under simultaneous external
1 Scope and internal mechanical load.
2 General requirements imposed on welded joints
– Permanent watertight joint of the PE-HD casing in all operating
3 Material
conditions and load cases.
4 Types of execution of welded joints on PE-HD casing pipes
4.1 Casing pipe/Sleeve joints – Transition of the forces acting on the sleeve into the casing
4.2 Welds on fittings pipe, caused for example by the increased resistance of the
5 Carrying out the welding process soil pressure in the sliding region. The increased soil
5.1 Heated plate welding (HS) resistance results from the thermal expansion of the moving
5.2 Hot gas extrusion welding (WE) long distance heating piping, when the largest sleeve diameter
5.3 Electrofusion (HM) exceeds the diameter of the casing pipe.
5.4 Indirect heated tool sleeve welding (-)
5.5 Hot gas welding (W)
6 Testing the welded joints 3 Material
Reprinting and copying, even in the form of excerpts, only with the consent of the publisher

6.1 Tensile test

6.2 Technological bend test The material to be used for the casing pipe, for sleeves and
6.3 Manual peel test fittings and if necessary the welding filler is PE-HD DIN 8075 –
6.4 Tensile creep test with the strength properties in terms of creep behaviour
6.5 Imperviousness test corresponding to the State of the Art (as dealt with in Section 8.3
7 Requirements imposed on welded joints of this Directive). In order to ensure weldability, the parts to be
7.1 Visual examination welded and if necessary the welding filler materials used must
7.2 Mechanical-technological tests in the short-term test correspond to the melt index groups 005 and/or 0101) to DIN
16776 Part 1.
7.3 Tensile creep test
7.4 Imperviousness test
8 Quality Assurance 4 Design versions of welded joints on PE-HD casing pipes
8.1 Quality Assurance for casing pipes and fittings in the Manu-
facturer's Works Forms of application of welded joints are found as tube/sleeve
8.2 Proofs of Quality for casing pipes and fittings joints and in the manufacture of fittings. The tube/sleeve joints
8.3 Quality Assurance of the welding work are welded on site, welds on fittings are produced both on site
9 Standards, Directives and also in the works.
9.1 Standards
9.2 Directives 4.1 Tube/Sleeve joints
Annex 1 Report Form (Proposal) for electrofusion methods
Annex 2 Report Form (Proposal) for heated plate welding 4.1.1 Heated plate welding (HS)
Annex 3 Report Form (Proposal) for extrusion welding
Heated plate welding2) is used in the works for producing fittings.
Annex 4 Report Form (Proposal) for imperviousness test
For reasons of design this method is not customary for tube/
Annex 5 Test content and implementing internal and external
sleeve joints.
monitoring
Annex 6 Determination of the time factor and a fictitious joining
4.1.2 Extrusion welding (WE)
factor for a welded joint
Annex 7 Stressing of KMR welded sleeves In extrusion welding the two weld shapes V-weld and fillet weld
are produced. Extrusion welding is customary both for the
manufacture of fittings in the works and for tube/sleeve joints.
1 Scope
4.1.2.1 Butt weld with V-weld, Fig. 1.
The Directive applies to all PE-HD welds on components of
plastic casing pipe systems. These include in particular the joints The sleeve tube, which has the same outside diameter as the
of the PE casing pipes and elbows, T-pieces, reducers and casing pipe, is placed slotted in the longitudinal direction over the
special parts with sleeves. The guideline is applicable both to casing pipe. The sleeve tube is fitted with saw cuts on both sides
welds made in the works and for welds which are carried out on and the butt bevel preparation made. Then the circular seams
site. are welded and finally the longitudinal seam. The welding of the
circular seams is done by extrusion welding with a trolley which is
rotated around the tube on a special strap. Particular care must
2 General requirements imposed on welded joints be taken when making the butt region between the circular
seams and the longitudinal seam. Suitable welding shoe shapes
The following general requirements are imposed on the welded for V- welds, matched to the seam shape, must be used (see Fig.
joint: 1).

1) Melt index group 005 = MFI 190/5 = above 0.4 to 0.7 g/10 min. Melt index group 010 = MFI 190/5 = above 0.7 to 1.3 g/10 min.
2) Formerly called "Spiegelschweißen" ("mirror welding")

This publication was prepared by a group of experienced specialists working together in an honorary capacity, and it is recommended that it should be respected as
an important source of knowledge. The user must at all times check the extent to which the contents apply to his or her special case and whether the version available
to him or her is still current. Any liability on the part of the German Welding Society and of those participating in the preparation of this document is excluded.

DVS, Technischer Ausschuß, Arbeitsgruppe "Fügen von Kunststoffen"

in common with Arbeitsgruppe "Schweißen von PE-Mantelrohren" der Arbeitsgemeinschaft Fernwärme – AGFW – e.V.
bei der Vereinigung deutscher Elektrizitätswerke

Orders to: DVS-Verlag GmbH, P. O. Box 10 19 65, 40010 Düsseldorf, Germany, Phone: + 49(0)211/1591- 0, Telefax: + 49(0)211/1591-150
Page 2 to DVS 2207-5

Detail “X” accordance with the seam shape is to be used (see Fig. 5b).
V-weld, extrusion
welding with filler 4.1.3 Electrofusion

“X” In the application electrofusion is used with integrated heating

conductors.

4.1.3.1 Sleeve tube/Plate with built-in heating conductors for longi-

tudinal and circumferential welds, Fig. 3
With this method the sleeve tube is made in the works from a
sleeve tube/plate provided with heating conductors. For the
longitudinal seam a supporting element is incorporated. Then the
tube or the plate is placed around the prepared ends of the
casing pipes and secured with external clamping rings. At the
same time the clamping rings serve to apply the compressive
Figure 1. Basic design of a fitted sleeve with V-welds. forces during electrical heating, which are necessary for the
welding. Lap welds are used for the circumferential and
longitudinal seams.
Detail “X” Fillet welds, extrusion
welding with filler 4.1.3.2 Sleeve band with built-in heating conductors for longitudinal
and circumferential seams, Fig. 4
A longitudinally slit sleeve tube is fitted between the ends of the
casing pipes with the same diameter. Over the joint grooves in
the circular butt joint region and on the longitudinal butt joint a
Profile ring “X” band provided with heating conductors is placed and fitted to an
external clamping device during the heating.

Detail “X” Band with heating conductor

Spacer/pressure support

Figure 2. Basic design of a slip-on sleeve with fillet weld. “X”

4.1.2.2 Lapp joint with fillet weld, Fig. 2.
In this case the sleeve tube is not divided. There is no
longitudinal seam. The circular seams are executed as fillet
welds as described under 4.1.2.1. For fixing and centering the
sleeve and for forming a reliable root a profile ring rounded
towards the seam (for example of plywood or plastic) is inserted.
For seam shape see DVS 2209, Fig. 10, or Fig. 5b). Care must
be taken to ensure adequate overlap of the ends of the casing
pipes (make markings).
The execution of the extrusion welding takes place as described
under 4.1.2.1. A welding shoe for this fillet weld design shaped in Figure 4. Basic design of a welding sleeve with sleeve band.

Detail “X” Sleeve tube/plate

Heating conductor

Casing pipe

“X”

Figure 3. Basic design of a welding sleeve with a longitudinally slit sleeve tube or a sleeve plate.
 Page 3 to DVS 2207-5

4.1.3.3 Slip-on sleeve with built-in heating grids – The manufacturer's documentation must include detailed
For this variant, basically the same welding principle is used as working instructions for the welding method used and in
for the variants with heating conductors built into the sleeve tube particular indicate the welding parameters (guide value tables).
parts in the works, as described above. The essential difference – The welding area must be protected against environmental
is that the surface areas of casing pipe and sleeve must be conditions, such as moisture, wind and dust, strong solar
prepared and the heating conductor band only applied and fixed radiation and temperatures below + 5°C. The formation of frost
in the sleeve joint on site. Furthermore, the diameter difference and moisture film must be prevented.If welding work has to be
existing between the casing pipe and the sleeve must be formed carried out under unfavourable conditions, suitable protective
by hot forming before the welding process. Sleeve and butt joint measures must be taken in good time, such as for example
shape as in Fig. 3, but without longitudinal seam. covering, preheating of the pipe joints and sleeve parts,
erection of a protective tent, if necessary with heating.
4.1.4 Indirect heated tool welding
– An even temperature must be maintained in all parts to be
In this welding process the heat energy necessary for the welding welded and also around the tube circumference (∆T < 20 °C).
is supplied through the tube joint to the welding plane by
conduction from a heating band placed on the outside of the – The welding areas must be cleaned (in the case of traces of oil
sleeve joint and used as a ring clamping element. As a result the and grease with suitable solvents, for example industrially pure
diameter distance existing between the casing pipe and the spirit), and the surface oxidized by the oxygen of the air must
sleeve tube is overcome during the welding process by shaping be removed, for example by planing, scraping, milling. If wire
the sleeve on to the casing pipe when the material is in the brushes or emery cloth are used care must be taken to ensure
thermoplastic state. that even removal of the surface layer around the
circumference is achieved, no dirt particles are "rubbed in" and
4.2 Welds on fittings abraded residues are thoroughly removed (blowing, brushing
Basically the various designs of bends and T-pieces used are clean etc.). The tools used must be kept clean and free of
mainly manufactured or prepared in the works. Making fittings on grease and must be checked and if necessary cleaned before
site is to be avoided, because the conditions are less favourable. use.
– Sleeve parts with incorporated heating conductors must be
4.2.1 Bends
supplied to the welding site in their packing and before welding
4.2.1.1 Finished bends the surfaces to be welded must be cleaned, for example with
industrially pure spirit.
The PE casing pipe of the bend is manufactured from tube
segments in the manufacturer's works by heated plate welding. – The cleaning and machining of the welding planes or welding
surfaces must take place immediately before the welding. The
4.2.1.2 Assembly bends machined surfaces must be protected against further
In order to equip bends on site with the PE-casing outside the contamination and may not be picked up again. Otherwise
prefabricated angle range also, prefabricated assembly bends repeated machining is necessary.
are used. For this the PE segment bends are longitudinally split – Adequate working space must be made around the welding
on the site, so that the part can be placed around the steel piping. site, so that the particular welding process can be carried out
The longitudinal cut is welded in the site trench. For this purpose reliably.
extrusion welding should be used.
– The tube joints, fittings, sleeve parts, etc., must be supported,
4.2.2 T-pieces aligned and fixed securely in the intended position.
Branches for connecting lines from the main piping are called T- – The welding work must be carried out and monitored by
pieces. The diameter ratios D1 to D2 are usually different. qualified welders (see Section 8.3). It is recommended that
meaningful work reports be prepared concerning the welded
Both T-piece designs with "outward necking" and heated plate
joints (for report form suggestions see Annex) and the joints
butt welding and designs which are produced by extrusion
permanently marked.
welding are usual. Similarly, combined applications of these
welding processes are customary. In special cases the work also – The welded joints may only be subjected to load after cooling
takes place on site, as described under 4.2.1.2 to ambient temperature.
4.2.3 Valves The preparations and conditions specific to each welding process
and the execution of the welding processes are described below.
PE casing pipe constructions of the most varied kind are
necessary for valves to be used in the soil, such as ball valves, 5.1 Heated plate welding (HS)
slide valves, butterfly valves or compensators. These
components are made in the works. The welding methods used This welding method is used in the case of PE casing pipe
for installing them are heated plate butt welding and extrusion exclusively for manufacturing tube bends and other prefabricated
welding. fittings in the works. The preparation and execution of the
method and the requirements imposed on the welding machines
4.2.4 Special fittings used are governed by the stipulations in the Directives DVS 2207
For the PE casing pipe constructions of anchor points, reducers, Part 2 and DVS 2208 Part 1.
end caps and other parts, as far as possible components
prefabricated in the works by extrusion welding or heated plate 5.2 Hot gas extrusion welding (WE)
welding should be used. Of the process variants described in Directive DVS 2209,
Variants II and V are mostly used in modified, partially
mechanized versions.
5 Carrying out the welding process
With process variant II, using a hand instrument, longitudinal
In the PE casing pipe field of applications joints must be made seams on fitted sleeves are welded. Also in the case of repair
both by producing fittings in the works and also in the course of work, if sleeves tubes have to be installed later, i.e. they must be
the pipelaying work under site conditions – usually in trenches. In previously split longitudinally for fitting and welded in the
order to achieve high quality welded joints, in addition to the installation position by butt welding with a V-seam. Furthermore,
special preparations necessary for the individual working these manual process variants are used for auxiliary welds in
methods the following conditions must be created, independently regions near to fittings and the like which cannot or can only with
of the method: difficulty be reached by machines.
Page 4 to DVS 2207-5

For welding sleeve circumferential welds as per Variant II circumferential welds in the region at the beginning of the weld)
partially mechanized equipment is used. To reduce the and after welding over with the welding unit tilted forwards the
necessary working space the welding machine is arranged in a material being welded must be held with a hand plunger.
narrow angular position with respect to the tube axis and
equipped with a suitably matched angular welding shoe – and is – Ejected accumulations must be removed down to "healthy"
carried in a manually operated trolley running on rollers in an weld (notch-free rounded shaving).
orbital frame around the tube circumference. To ensure reliable
guidance and better matching of the equipment speed of
advance to the other welding conditions, steplessly controllable
motor drives must be provided. The welding filler is fed in in wire
form, for example 4 mm diameter, from the supply unit Welding shoe
(encapsulated roll stands, if possible with preheating and drying
system). Melt channel

The heating of the welding zone is done by hot air. Adequate

plastication of the PE material beyond the side wall edges and in
the weld root region requires optimum adjustment of the hot air
nozzle to the joint to be welded (V or fillet welds, curvature of the
weld paths, joint width). The parameters, such as air volume/
temperature and welding speed, must be matched to the filler-
ejection power of the equipment.
The equipment Variant V in the version for casing pipe welding
differs only in the machine side plastication for the welding filler. a) Welding shoe for V-seam: joint opening approx. 60o
This works on the piston principle, in which the filler wire (smaller wall thickness to 80o (greater wall thickness)).
introduced – driven in the infeed region – acts as a consumable
piston to bring about the ejection of the plasticized filler in the x = 0, i. e. without gap, if welding is done without backing.
heated cylinder. All other conditions and functions are as x = 1 – 2 mm, if welding is done with backing.
described above.
In both process variants the plasticized welding filler is brought
Melt channel Welding shoe
into the joint groove by extrusion through the shaping "welding
shoe". In order to achieve adequate welding, i.e. adequate melt
pressure in the welding filler in the critical areas of the seam (root
and upper runoff edge), the welding shoe must have a front
"shoe tip" matched to the joint and adequate overlap length (Fig.
5). For the usual weld thickness in the range of applications up to
approximately 10 mm tube wall thickness an overlap/holding
length of 40mm after the runner is necessary.
The shoe shapes must be matched to the joint shapes depending
on the type of weld (overlapping butt-fillet weld) and the
curvatures to the necessary degree. The lateral sealing surfaces
together with the front "shoe tip" form the clamping for the
welding filler introduced by the extrusion and thus the condition
for the necessary pressure build-up in the weld material. These
sealing surfaces should be approximately 5 mm wide. All Profile ring
transitions and edges must be carefully rounded, so that during
b) Welding shoe for overlapping butt fillet weld:
welding no plasticized compound is "shaved off" the joint side
The upper edge must also be bevelled with a negative angle
walls causing defects. For extrusion welding see DVS Directive
of up to 15o.
2207 Part 4.
The edges must always be rounded!
For the carrying out of the welding the following are necessary:
– A visible positioning and fixing of the parts to be welded
(casing pipe and tubular sleeve) in the intended butt weld Feed direction
shape; if necessary short tack welds in the weld root.
– Precise centering and adjustment of the orbital frame over the
course of the joint groove; therefore the machining of the joint
surfaces with tool systems must take place in the same frame Welding shoe
setting as the welding.
Melt channel
– Control and tracking systems for continuous adjustment of the
welding unit (direction and position of the welding shoe) and Tip of welding shoe
the hot air nozzle position (central in the median line of the joint
opening).
– Stepless speed adjustment of the welding carriage and control
by intensive observation of the welding point and/or the melt
delivery.
Butt weld side wall of a
– Monitoring of adequate joint heating directly in front of the V-seam in the tube joint
welding unit by penetration tests with blunt tools (thin
screwdriver). c) Welding shoe for V-seam in the middle of the seam
(lingitudinal cut)
– Correct execution of the end regions to be overlapped in the
case of circumferential welds and longitudinal welds. The Figure 5. Schematic drawings for executing weld sheos for extrusion
groove must be adequately bevelled (in the case of welding for V-seams and overlapping butt fillet welds.
 Page 5 to DVS 2207-5

5.3 Electrofusion *) (HM) – Removing the welding pressure only after the welding zone
The process variants used in practice are based on sleeves or has cooled down sufficiently to approximately + 90 °C; indicati-
sleeve plates with heating conductors with 3-sided conductor ons of the time for this must be taken from the process instruc-
arrangement incorporated in the works (additionally for the tions of the manufacturer.
longitudinal seam), or use for the particular size inlaid heating 5.3.2 Slip-on sleeve with inlaid heating grid
grids prepared in the works, which are mounted and fixed in the (cf. also Section 4.1.3.3)
lap joint on the casing pipe.
As far as the equipment is concerned, basically for this process
The requirements imposed on the welder in all process variants variant the same principles as described under 5.3.1 apply. In the
essentially relate to careful execution under site conditions. execution basically the following process-specific jobs must also
These are in particular: be carried out:
– The preparation of the casing pipe joints, – Determining and marking the welding regions in the joint.
– The correct assembly and fixing of the welding sleeves – Cleaning and machining both surfaces in the welding regions
including the clamping and holding systems and (casing pipe and tubular sleeve).
– The making of the electrical connections to the welding – Adapting the heating grid strip to the tube circumference by ap-
equipment. propriate stretching, positioning of the strip and fixing accor-
ding to the manufacturer's instructions; take note of the alloca-
With modern equipment the welding process itself is tion marking of the heating grid strips!
automatically controlled on the basis of previous automated
actual value sensing of the critical initial values (such as – Assembling the tubular sleeves in the predetermined position.
resistance as a measure of the sleeve nominal diameter, ambient – Adapting the slip-on sleeves to the diameter of the casing pipe
and component temperature) and automatically controlled as it by hot forming. The sleeve ends are heated evenly to the for-
progresses on the basis of power consumption measurements. ming temperature over an adequate width in the region of the
After the equipment has been basically set the welder has only a heating strips and clamping elements (approx. + 100 °C).
supervisory function during the welding process. (Take care when using naked flame; use "soft" liquefied gas
flame). The adapting of the diameter is done by fixing the clam-
As far as equipment is concerned, with these methods the ping members and applying the pressure without delay. The
systems must be equipped with measurement value sensing and latter is used after starting the welding process for applying the
digital recording systems, so that each sleeve joint can be joining force.
documented with conclusive parameter and parameter change
reports. The other functions and operations are the same as in the works
sequence previously described.
5.3.1 Tubular sleeves/sleeve plates with built-in heating conductors
(cf. Sections 4.1.3.1 and 4.1.3.2) 5.4 Indirect heated tool sleeve welding (–)
(cf. Section 4.1.4)
In respect of the introduction of energy into the joint is concerned,
the prescribed welding parameters must be matched in particular The heat input necessary for the welding of the lap joint on the
to the wall thicknesses, the semi-finished product and ambient sleeve connection takes place indirectly by heat conduction
temperaures and the material melting characteristics. The through the wall of the sleeve to the welding plane. The metal
process must then be controlled with the pressure generating unit heating strip applied to the outside of the sleeve joint is also used
for the welding pressure in system coupling. The welder on the through a hydraulic clamping system as an orbital clamping
site cannot control the welding process, because with this weld element for applying the joining force for the welding.
shape in the lap joint and with the superstructure formed by the According to the system the temperature profile across the
pressure generating devices he cannot look into the welding sleeve wall on the outside of the sleeve has a higher temperature
plane and therefore any controlling influence over the welding than the welding point on the inside; the profile of the melt
process is out of the question. viscosity runs in the same way. Because the clamping ring
For reproducible reliable production of high quality welded joints presses the sleeve joint over the entire plasticized sleeve wall the
according to these process variants welding units with preset heating strip is pressed into the tube wall, i. e. a "notch" is
parameters and process controls optimized for the particular produced by wall thickness reduction in the welding region.
application are necessary. For the quality of the welded joints the During the welding process at the same time the annular gap
welding and supervisory personnel must correctly and carefully existing between the casing pipe and the sleeve tube is closed by
create the external preconditions on the basis of the stipulations the clamping of the heating strip ring which causes thermoelastic/
of the process instructions. These are in particular the following plastic material deformation. The external step formation under
steps: the heating strip position and the wall thickness reduction of the
sleeve in the weld region are forced to increase with the size of
– Dimensionally correct marking of the sleeve position and/or the
the sleeve annular gap. For this reason the use of this process
welding regions.
variant is limited to small casing pipe diameters (at the moment
– Trimming of the tube joints and fitting supporting sections for up to maximum 400 mm).
the longitudinal welds.
To what extent this "notch formation" which weakens the weld
– Machining of the tube surfaces in the weld regions, taking care start region is acceptable from a strength point of view must be
to avoid recontamination when the sleeve is subsequently as- demonstrated for the particular application.
sembled (clean slip-on sleeves and casing pipes inside and
The energy supply of the welding equipment must be
outside beforehand).
programmed to the tube size and to the semi-finished product
– Positioning and fixing of the tubular sleeves or sleeve plates - and ambient temperatures. As far as the application of pressure
in the predetermined position with rigid straps. is concerned, the annular clamping system must be
synchronized with the heating process. The corresponding
– Setting up the pressure generating devices and clamps.
information must be taken from the process instructions of the
– Making the electrical connections, and the pressure connec- system manufacturer.
tions and control connections, followed by examination to avoid
The weld preparation and the other operations are subject to the
confusion, and function monitoring of the welding machine.
same basic stipulations and operational steps as described for
- Starting up and monitoring the welding process. the process in Section 5.3.

*) DIN 1910 Part 3: “Sleeve welding with incorporated electric heating element”
Page 6 to DVS 2207-5

Joining weld Joining weld

Specimen Shape 1
(Strip specimen) Specimen Shape 2
(Shoulder specimen)

Figure 6. Specimen shapes for the tensile tests.

5.5 Hot gas welding (W) The force at the moment the specimen tears must be recorded. If
the specimen should neck, this yield stress is the reference
The method is described in Directive DVS 2207 Part 3. With the
method of hot gas welding with filler, for example hot gas string- stress (FB). Tests during which the specimens tear in the
bead welding with welding wire – generally lower long-term weld clamping region should be disregarded and must be repeated.
strengths are achieved than with the welding methods described
above. This is all the more so, if the welding work has to be 6.1.2 Evaluation
carried out under difficult conditions; on sites and mostly in
trenches in the case of circumferential welds. For the welded specimens FV and the unwelded specimens
(reference specimens) FB the short term joining factor fz = FV/FB
For these reasons hot gas welding should not be used on lines is determined from the mean values of the tearing force, in the
with PE-casing pipes. case of different specimen dimensions, from the stresses
referred to the specimen cross-section.
If because of local circumstances this method cannot be avoided
in exceptional cases, particular care must be taken during
execution. The requirements of DVS 2203 Part 1 must be 6.2 Technological bending test
fulfilled.
For assessing the execution of the weld the technological
bending test in combination with other tests can be used. The
bending angle and the fracture photomicrograph give an
6 Testing the welded joints indication of the deformability of the joint and thus of the quality of
the execution.
For the testing of welded joints the test methods described in the
following can be used, taking into account the requirements The bending test is carried out on the basis of the Directive DVS
imposed and/or the conclusions required. 2203 Part 5 and/or DIN 50 121. The bead is machined away in
the region where the bending punch is applied. The edges on the
The results of the short term tests however can only be
tensile stressed side must be broken. Six welded specimens are
transferred to the long term behaviour of the welded fabrication to
tested. The tensile stress is applied both to the root and to the
a limited extent. Specific demonstrations of the long term
overlay of the welded joint (3 specimens each).
behaviour are only possible by means of long term tests.
Generally the specimens must be manufactured by sawing, Information about the shape and the dimensions of the
milling or water jet cutting (not stamping). specimens and the test arrangements is contained in Table 2.

6.1 Tensile test Table 2. Dimensions for the test arrangement for the technological
The tensile test is carried out in accordance with DIN 53 455 or bending test (from DVS 2203 Part 5).
DVS 2203 Parts and 1 and 2. The welded joints are tested in Specimen Supporting Bending beam
accordance with the actual execution, i.e. with or without bead. width thickness
The joint lies in the middle of the specimen. At least 6 welded and Thickness Width Length
LS d
6 unwelded specimens (reference specimens) are tested. h

If the strip specimens of Shape 1 to Fig.6 tear in the clamping 3<h≤5 20 150 80 4
region, specimens of Shape 2 must be used. The dimensions of 5 < h ≤ 10 20 200 90 8
the particular specimen shape should be taken from Table 1. 10 < h ≤ 15 30 200 100 12,5
15 < h ≤ 20 40 250 120 16
20 < h ≤ 30 50 300 160 25
Table 1. Dimensions of the specimens for the tensile test.
In the case of lap welded joints the dimensions L and Lf must be On smaller tubes if necessary a smaller specimen diameter
increased by the welded overlap length.
should be chosen. However, 15 mm should be the minimum.
Thickness Specimen Shape 1 Specimen Shape 2
h 6.2.1 Execution
b Lf L b Lf L be
< 10 15 120 ≥ 170 10 115 ≥ 170 20 Unless agreed otherwise, this test is carried out at room
> 10 30 120 ≥ 300 30 115 ≥ 300 40 temperature (+ 23 °C ± 2 °C). The specimens of PE-HD are bent
> 20 1,5 h 200 ≥ 400 1,5 h 200 ≥ 400 80 in the test rig at a test speed of 50m m/min until fracture/incipient
tearing. The arrangement of the bending beam should be taken
6.1.1 Execution from Fig. 7 for the various design versions of the joints.

Unless agreed otherwise, the test is carried out to DVS 2203 Part The bending angle reached on incipient tearing or fracture is
2 at room temperature (+ 23 °C ± 2 °C). For determining the measured. Complete bending of the specimen, without tearing or
short term strength the specimens are pulled at constant test fracture, corresponds to a bending angle of 160° and is to be
speed. For PE-HD the test speed is 50 mm/min. evaluated as > 160°.
 Page 7 to DVS 2207-5

Fig. 8 until fracture or until the free ends of the specimen come
into contact with the bar.

a)

b)

Figure 8. Diagrammatic representation of the manual test.

“X”
6.3 Manual peel test
The manual peel test is a simple, indicative workshop test carried
out by hand, which can also be carried out on site. This test is
intended in particular for lap welded joints, for example
c) electrofusion-welds, which cannot be directly tested using the
technological bending test as per Section 6.2.

6.3.1 Execution
The execution can only take place after adequate cooling of the
joint to room temperature (approx. + 23 °C). 5 strip specimens of
15 to 20 mm width – taken at intervals over the weld length – are
d) tested.
Here the end of the sleeve is clamped in the vice and the non-
welded end of the plastic casing pipe projecting into the sleeve is
Detail “X” bent away from the sleeve until it can be gripped by a pair of
pliers. Then an attempt is made to peel off the joint, see Fig.9.
Groove 1 mm deep, The free leg is bent until it kinks.
4 mm wide

Sleeve

Figure 7. Diagrammatic representation of the mechanical test and the

planes of action in the technological bending test (examples):
a) V-weld, root as tension side a) b)
b) V-weld, rear of weld under tension; during the test at a
Plastic jacket pipe
bending angle of approximately 90o,
Figure 9. Illustration of the specimens for the manual peel test;
c) and d) die arrangement for the lap welded joint with fillet
weld (WE). 3 specimens each with the weld root (c) and a) strip specimen before the test
b) joint ends bent upwards for the peel test.
the joint side wall edges (d) under tension.

6.2.2 Evaluation 6.3.2 Evaluation

The technological bending test does not supply mathematical The joining surfaces should not separate.
values for the design calculations. On the basis of the deformati-
on behaviour determined and the fracture photomicrograph the 6.4 Tensile creep test
results however allow a general qualitative assessment of the The long-term behaviour under the required forms of stress is the
joint to be made. most important proof of quality in relation to the suitability for use
For a general good/bad assessment the minimum requirements of load carrying components made of thermoplastic polymers. In
indicated in Fig. 14, Section 7, of Directive DVS 2203 Part 1 can the case of pressure loaded structures, such as pipes and
be taken as the basis. fittings, carrying out the long-term internal pressure test has been
the proven state of the art for a long time. For pipes of larger
For max. 2 specimens, which do not fulfill the requirements, 2 dimensions, however, these tests are increasingly expensive in
replacement specimens each from the same part can be tested. cost terms, so that this test is only seldom used in testing
No value should lie below the required minimum value. practice.
6.2.3 Manual test To assess the execution of the weld the long-term tensile test in
combination with other tests has proved itself. The tests are
This version of the technological bending test is a simple
carried out at + 80 °C. The applied stresses are 4 and 3 N/mm2.
indicative workshop test. Because of the force required this
If no brittle fracture should occur during the execution of the test,
method is limited to small thickness specimens. lower stresses must be chosen. In order to shorten the time-to-
The specimen is bent with the machined side of the weld over a failure (acceleration effect), a 2% aqueous wetting solution (for
rounded, 6 mm thick bar with powerful application of force as per example Arkopal N 100 3) ) should be used as the test medium.

3) (R) Messrs Hoechst AG. Extensive testing experience is available for this test medium, which facilitates comparison of the results and the determination
of requirements. If other products on the same basis are used, compare the number of ethylene oxide molecules in the polyglycol ether chain.
Page 8 to DVS 2207-5

The required joining factors (fs) in the tensile creep test (Table 4, 6.4.2 Evaluation
Section 7) and the fracture photomicrograph give an indication of For determining the long-term joining factor4) (fs) the creep curve
the quality of the weld execution. of the welded and unwelded specimens must be determined, the
gradient of the straight lines being particularly important. The
6.4.1 Execution tensile creep joining factor – referred to a particular stress on the
The tensile creep test is carried out in accordance with DVS 2203 reference curve B – is calculated from the curve obtained for the
Part 4 or DIN 53 444 (Fig.10). The welded joints are tested in welded specimen: see examples in Fig.11.
accordance with the actual execution. Alternatively, the ong-term joining factor can be referred to one
test stress on the reference specimen. The joining factor
determined must then be identified, with indication of this test
dial gauge stress (for example σ4(B)), see Fig.12.
Simplified method for minimum proof of a required long-term
joining factor
To reduce the complexity of the test the proof can be limited to
one stress level in each case using the following method, see
Fig.13.
For example:
– Test stress for the basic material (reference specimens)
σB = 4 N/mm2
specimen – Test stress for the weld specimens with for example fs = 0.8
σS = fs · σB = 0.8 · 4 N/mm2 = 3.2 N/mm2.
test medium
If the weld specimens reach at least the same mean time-to-
tank test weight failure as the base material, at least the required long-term
joining factor is demonstrated (yes/no statement).
With this test no conclusion about the stress-related strength
behaviour is possible.

6.5 Imperviousness test

Figure 10. Test set-up for the tensile creep test (on the basis of DVS Normally a positive pressure test with compressed air at approx
2203 Part 4). 0.2 to 0.3 bar is carried out. After a test duration of at least 10
minutes after coating the welds with a harmless foaming aqueous
For the shapes and dimensions of the specimens the specimen solution (for example a modern biologically degradable
shapes (Fig.6) indicated in Section 6.1 "Tensile Test" with Table household detergent in the lowest concentration) no leaks must
1 are applicable. For this test the use of the same specimens is be visible (bubble formation).
recommended. The joint position lies in the middle of the
specimen, the longitudinal axis of which must lie in the direction
of the tensile force. 7 Requirements imposed on welded joints
The specimen must be made without notches and if necessary
The welded joints on PE-HD casing pipes and fittings must – just
retouched after visual examination (for example grinding in the
like the tubes – reliably withstand the stresses occurring in
longitudinal direction). In the tensile creep test the duration until
operation over the design duration of stress.
fracture of the specimen and, if necessary, the increase in
elongation with time are determined. As a rule welded joints on PE-tubes do not achieve the same
material strength as the unwelded casing pipe. The piping
The specimens are stressed at constant temperature (± 1°C) with planning and design must indicate the weld qualities achievable
uniformly steady tensile force (± 1%) and constant ambient with the welding methods used. The required weld qualities must
conditions. be guaranteed by suitable measures and test methods.
In order to ensure even concentration of the wetting agent, it Therefore corresponding requirements must be imposed on the
must be circulated continuously in the test bath. The bath welded joints.
concentration of the test medium must be monitored by control In the Directive DVS 2203 Part 1 requirements imposed on
measurements – in its spatial distribution also – (for example by plastic welded joints are described for certain moulding
residue determination by evaporation). Evaporated water must compounds and welding methods, as are applied mainly in tank,
be topped up by adding demineralized water (deionate) vessel and piping construction. In these fields of application the
continuously (level control). plane butt joint without transition is used and welded.
After reaching the bath temperature the specimens are In the case of lines with PE-casing pipes the multiple lap joint is
vigourously stressed with the test force but without impact in the also often used in special process variants, however from a test
test bath, the force being maintained constant during the test. point of view and also in respect of the requirements imposed it
The duration of loading is calculated from the moment the test cannot be immediately treated and assessed. Otherwise the
force is reached and recorded by built-in dial gauges. requirements of the Directive quoted apply.
In order to determine the gradient of the creep curve (straight
7.1 Visual test
lines in double logarithmic form), the tests are carried out under
at least 2 stresses (for example 4 and 3 N/mm2). At least 6 In the visual test the defect-free execution of the welded joint
welded and 6 unwelded specimens are tested for each stress. must be demonstrated by visual examination. In combination with
The mean value is calculated as the geometric mean of the destructive tests the weld cross-section and fracture surfaces
individual values. must also be assessed. Typical test features are:

4) On the basis of the shape and nature of the lap welded joints involved here with superimposed types of stress in the joints in the tensile test, the long-
term joining factor is defined here, as a departure from DVS 2203 Part 4.
 Page 9 to DVS 2207-5

– a process-specific, correct weld/weld edge formation (root and – homogeneity of the material being welded; weld surface
edge welding) – weld flash, weld shoe guidance (WE)
– presence of notches, cavities, lack of fusion, etc – bulge/double bulge formation (HS, WZ)
– the effect of heat, fusion zones, overheating, etc Defect descriptions and evaluation references are also given in
– shape and uniformity of the weld formation DIN 32 502 and DVS 2202 Part 1.
Stress (N/mm2)

S = weld specimen
B = reference specimen

Time-to-failure (h)

Figure 11. Diagramatic representation for defining the joining factor in the tensile creep test.
Stress (N/mm2)

S = weld specimen; σ4 and σ3

B = reference specimen; σ4

Time-to-failure (h)

Figure 12. Diagram for defining the joining factor in the tensile creep test in the case of only one test stress on the refrence specimen.

7.2 Mechanical-technological tests in the short-term test proposed as an alternative for these joint shapes the surfaces to
be joined must not separate.
In principle, in the short-term tests described (tensile and
technological bending tests) the requirements of DVS 2203 Part With this form of joint the technological bending test cannot be
1 must be satisfied; see Table 3 and Fig.14. carried out easily. Likewise, essentially only the weld edge
regions are covered by the test.
In the case of lap welded joints with flat welding in the joint the
result of the tensile stress is primarily determined by the weld The results of these tests have less informative value for lap
edge execution; the welding itself is covered to a lesser extent in welded joints, in particular for flat welds in the lap joint, than for
this tensile/shear test. During the manual peel test to Section 6.3 plane butt joints.
Page 10 to DVS 2207-5

Stress (N/mm2)

S = weld specimen
B = reference specimen

Time-to-failure (h)

Figure 13. Simplified method for minimum proof of a required long-term joining factor.

Table 4. Requirements for the joining factor in the tensile creep test
for the reference stress σ = 4 N/mm2 (on the basis of DVS
2203 Part 1).

Welding method Tensile creep

joining factor fs
Heated plate welding 0.8
V-weld extrusion welding 0.6
Extrusion welding on the lap joint with fillet
weld 0.5*)
Bending angle

Electrofusion in the lap joint 0.5*)

*) At present values from approximately fs = 0.4 are accepted. This low

value is permitted in order to take into account the falsification of the
tensile test due to the superimposed bending stresses, increased
inherent stresses and notch effects, etc.

7.3 Tensile creep test

In the tests as per Section 6.4, for correctly executed joints on

casing pipes at least the long-term joining factors "fs" required in
Table 4 must be demonstrated.
For the tubular semi-finished products (casing pipe and tubular
sleeves), under the same test conditions as in Section 6.4 for the
test stress 4.0 N/mm2, a minimum time-to-failure of 1500 hours is
required for the geometric mean value from at least 6 individual
specimen results, see Draft Standard DIN EN 253.
Specimen thickness
This single-point requirement in the creep diagram (+ 80 °C)
HS = Heated plate welding applies subject to the condition that the tube moulding material
LE = Light beam welding by extrusion of filler material basically satisfies at least the creep requirements in the internal
WE = Hot gas welding by extrusion of filler material pressure test according to the creep diagram used as the basis
WF = Hot gas welding with torch separate from filler rod
WZ = Hot gas string-bead welding for DIN 8075.

Figure 14. Requirements for the technological bending test (from DVS In accordance with the current quality standard, here the inclined
2203 Part 1). load range of the curves is shifted in such a way along the time
axis that the test point (4.0 N/mm2 /+ 80 °C) lies at 1000 hours.
Table 3. Joining factor requirements in the shoert-term tensile test In comparative tests it has been shown that in the case of the lap
(on the basis of DVS 2203 Part 1).
welded joints the deformations in the test specimens (strips or
Welding method Short-term tensile shoulder specimens) have no influence on the test result (pairs of
joining factor fz forces).
Heated plate welding 0.9
V-weld extrusion welding 0.8
7.4 Imperviousness test
Extrusion welding on the lap joint with fillet
weld 0.8 During the imperviousness test (as per 6.5) no leaks, atypical
Electrofusion in the lap joint 0.8 deformations or other impermissible changes may occur.
 Page 11 to DVS 2207-5

8 Quality Assurance The welders used must demonstrate adequate training5) in the
material science of PE- HD, having passed the welder
Because the quality of plastic welded joints for specific examination6). These must be carried out and certified as per
applications can in the last analysis only be demonstrated by Directive DVS 2212 or in rational application for the particular
destructive long term tests, the quality assurance must be based method. For the methods WZ and HS DVS 2212 Part 1 and Part
on indices, identity and reproducibility proofs. 2 apply to extrusion welding.
Therefore, for the quality assurance of welding work in the case The execution of the welding work in the manufacturer's works
of joints in PE-HD casing pipe and fittings, in addition to the use (prefabrication of fittings) and – in particular – on the site under
of moulding compounds and tube products with fixed indications difficult conditions in pipe trenches, must be supervised by a
of product qualities, qualification requirements must be imposed qualified responsible welding inspector of the manufacturer's
on the skilled welding personnel and minimum requirements on works.
the equipment and workplace arrangements of the contracting The welding inspector must supervise in particular
companies.
– The use of suitable welding equipment and accessories in a
8.1 Quality assurance for casing pipes and fittings in the functionally reliable condition,
manufacturer's works – The correct arrangement and preparation of the joints
The measures for quality assurance in the manufacturer's works – The qualified execution of the welding processes in accor-
are normally divided into two. According to DIN 18 200, a dance with the particular prescribed methods (Manufacturer's
distinction is made between internal and outside supervision: instructions, DVS Directives, etc.) if necessary using suitable
– Internal supervision protective measures (protection against weather, etc),
Tests by professionals of the manufacturer's works based on – Adequate recording of the welds (for suggested report forms
established test and work instructions. see Annex) with welder identification and documentation of the
– Outside supervision joints in accordance with what is stated in the manufacturer's
These are used to permit the regular checking of the equip- specifications and DVS Directives relating to the method.
ment and operations of the internal works inspectors, their do- Finally, he carries out
cumentation and test procedures by outside supervisors. For
the application described here, as a rule the outside supervi- – The visual examination of the finished welded joints for defect-
sion is carried out and administered by suitable independent free execution and
plastics test centres and experts as per DIN 18 200. As a rule – The imperviousness test
outside supervision dates are observed and certified twice per
and prepares a test report on these.
year. The results of the supervision inspections must be docu-
mented and the test reports of the outside inspector included The welding inspector is responsible to and reports to the
in the manufacturer's documentation. Employer/the Site Management.
For the execution of the welding work done by the Employer,
8.2 Proof of quality for casing pipes and fittings
outside supervision is recommended on a random basis.
For the casing pipes and fittings used tests must be carried out in
accordance with the basic standards, moulding compound and
moulding guidelines already in existence for the products or 9 Standards, Directives
according to a product-specific test and supervision program.
The test results obtained must be specified and documented, 9.1 Standards
contrasted with the established requirements. DIN EN 253 Preinsulated bonded pipe systems for underground
The content of the test must be based on: (Draft) hot water networks – Pipe assembly of steel
service pipes, polyurethane thermal insulation and
– DIN EN 253, 448, 488 and 489 for PE-HD casing pipe materi- outer casing of high density polyethylene.
als DIN EN 448 Preinsulated bonded pipe systems for underground
– DIN 8074/75 applied rationally, in particular in respect of the (Draft) hot water networks – Fitting assemblies of steel
long-term tests. In the case of the larger tube diameters with service pipes, polyurethane thermal insulation and
smaller wall thicknesses tensile creep tests are preferable to outer casing of high density polyethylene.
the otherwise customary long-term internal pressure tests in DIN EN 488 Preinsulated bonded pipe systems for underground
this respect. For the minimum time-to-time failure rates the (Draft) hot water networks – Steel valve assembly of steel
requirements under Section 7.3 apply. service pipes, polyurethane thermal insulation and
The proofs of quality must be produced by the manufacturing outer casing of high density polyethylene.
works at least in the form of "Works Certificates" as per 2.2, DIN DIN EN 489 Preinsulated bonded pipe systems for underground
50049. For the content of the tests and the application of internal (Draft) hot water networks – Joint assembly steel service
or outside supervision, see Annex 5. pipes, polyurethane thermal insulation and outer
casing of high density polyethylene.
8.3 Quality assurance of the welding work DIN 1910 Welding, Welding of plastics, methods
Process tests must be demonstrated by the contracting Part 3
companies and skilled workers for the welding method applied DIN 8074 Tubes of high density polyethylene (PE-HD),
(proof by the manufacturing company that it is in a position, with dimensions
its skilled personnel and the physical equipment of the company,
to execute the welding work correctly and reproducibly in DIN 8075 Tubes of high density polyethylene (PE-HD),
accordance with the high requirements imposed. general quality requirements, testing

5) Training centres for PE welders:

– Süddeutsches Kunststoff-Zentrum, Frankfurter Straße 15-17, D-97082 Würzburg
– Training centres under supervision of the Institut für Kunststoffverarbeitung at Aachen
University of Technology, Pontstraße 49, D-52056 Aachen
6) Examination centres:
- the Training Centres mentioned under 5) and
- the TÜV Plastic Test Centres; for information: Association of the Technical Supervision Societies, Kurfürstenstrasse 56, D-45038 Essen.
Page 12 to DVS 2207-5

DIN 16 776 Polyethylene (PE) moulding compounds DVS 2205 Design of containers ans appaartus made from
Part 1 – Classification and description thermoplastics
Part 2 – Manufacturing the test specimens and Part 1 Characteristic values
determining the properties Part 3 Welded joints
DIN 16 963 Pipe connections and piping components for high DVS 2206 Testing of components and constructions made of
Part 5 pressure pipelines of high density polyethylene thermoplastic materials
(PE-HD); general quality requirements, testing DVS 2207 Welding of thermoplastics, PE-HD (high density
DIN 18 200 Supervision (quality monitoring) of building Part 1 polyethylene) Pipes and pipeline components for
materials, components and structures, general gas and water mains
principles Part 2 Heated plate welding – pipes and pipelines for
DIN 32 502 Effects on welded joints in plastics, classification, sewerage pipes and lines
designation, explanations Part 3 with Annex Hot gas welding of thermoplastics –
DIN 50 049 Certificates for material tests sheets and pipes, welding parameters)
DIN 53 444 Testing of plastics, tensile creep test Part 4 Welding of thermoplastic polymers, panels and
DIN 53 455 Testing of plastics, tensile test pipes – extrusion welding
DIN 53 479 Testing of plastics and elastomers; determining the DVS 2208 Machines and equipment for welding of
density thermoplastics
DIN 53 735 Testing of plastics; determining the melt flow index Part 1 – heated tool welding
of thermal plastics Part 2 – hot-gas welding (not extrusion welding)
ISO Plastics; determination of the melt flow index (MFR) DVS 2209 Welding of thermoplastics – extrusion welding,
1133:1991 and the volume flow index (MVR) of thermal Part 1 methods – features
plastics DVS 2211 Filler materials of thermoplatics, scope,
ISO Plastic pipes for conveying liquids; determination of designation, requirements, tests
1167:1973 the resistance to internal pressure DVS 2212 Testing of welders for welding plastics,
ISO Plastics; methods for determining the density and Part 1 Test group I (hot gas string bead welding and
1183:1987 relative density of non-expanded plastics heated plate welding)
ISO/DIS Tubes of polyethylene (PE); Part 1: Determination Part 2 Test group II; Hot gas extrusion welding (WE)
6259-1:1985 of the properties in the tensile test
GKR- Casing pipes for the manufacture of sleeves and
ISO/TR Determination of the thermal stability of Guideline fittings of PE-HD (high density polyethylene) for
10 837:1991 polyethylene (PE) for gas piping and fittings R 9.3.17 preinsulated bonded pipe systems for underground
hot water networks with the quality symbol of the
9.2 Directives Plastic Pipes Quality Association e.V., Bonn
DVS 2201 Testing of semifinished products of thermoplastics "Building of district heating networks" – Technical Guidelines of
Part 1 – fundamentals, references the AGFW
DVS 2202 Imperfections in thermoplastic welded joints – AGFW membbers information "Plastic jacket pipes for district
Part 1 features, description, evaluation heating lines".
DVS 2203 Testing of welded joints og thermoplastics
Part 1 Test methods – requirements
Part 2 Tensile test
Part 4 Tensile creep test
Part 5 Technological bending test
Assembly Report

This Annex is only for information and is not a binding part of this Directive.
Annex 1: Report form (proposal) for the electrofusion method
Order No.: Welder:

BV/Section: Welding machine No.:

Section No.: of: Power source: … Mains … Generator

Sleeve No. Type Section Date Ambient Weather Weather Displays Sleeve Remarks

Sleeve initial temperature (oC)

temperature protection
A B C (°C)

Replacement welds

Non-watertight
Temperature

Programme

Watertight
Rewelds
Screen
Cloudy
Sunny

Snow

Open
Wind

Time
Tent
Rain

Page 13 to DVS 2207-5

 Page 14 to DVS 2207-5
This Annex is only for information and is not a binding part of this Directive.
Annex 2: Report form (proposal) for heated plate welding
Report form for heated plate welding of tubular Laid above ground Material
Laid underground Sheet of
components
Employer Contracting company Welding machine Weather conditions Protective measures

Make: 1 = sunny 1 = none

2 = dry 2 = screen
Order title Name of the welder Identy No. Type: 3 = rain or snowfall 3 = tent
4 = wind 4 = hetating
Maschine No.:

Order No. Name and company of the welding Year of manufacture: In the case of multiple designations follow the sequence of the figures as above
inspector (e. g. 34 = rain and wind)

Weld Date Input data Adjustment/measurement values1): theoretical/acutal information Ambient conditions Remarks
No.
Pipe size Movement Heating Equalizing Heating up Joining Heating Adaption Time to Cooling Ambient Weathering Code No.
Ø dA × t pressure, element temperature up time2) time2) complete time under temperature code No. of the
measured, temperature’ joining joining protective
P pressure pressure2) measures
bar oC bar bar bar s s s s oC

Example: (10,5+10,7) (10,5+0,7) (10,5+10,7)

1 25.5.92 160Ø14,6 10,5 220 ± 5 21,2/ 11,2/ 21,2/ 130/ <10/8 ≈ 10/12 >20/20 ≈ 20 24 2 None

Signature of welder: Date and signature of the welding inspector:

1 )The settings are the sum of the movement pressure and the indications of the manufacturer of the welding machine concerning equalization and joining pressure.
2) The measured values must be entered.
 Page 15 to DVS 2207-5

Annex 3: Report form (proposal) for extrusion welding

This Annex is only for information and is not a binding part of this Directive.

Welding Report
for the extrusion welding of panels and tubes

General Information

Order No.: Drawing No.:

Contracting Company:

Welder (Name, Reference):

Process/Equipment

Process variants: Welding shoe No.:

Welding equipment (make):

Weld shape (e. g. DVS 2205):

Material

Material to be welded:

Semi-finished product shape, thickness (mm):

Welding filler:

Welding Conditions

Hot air temperature (°C): Air volume (l/min):

Cylinder heating (°C): Compound temperature (°C):

Hose heating: Welding speed (mm/min):

Remarks:

Date/signature Date/signature
Welder Welding supervisor
Page 16 to DVS 2207-5

Annex 4: Report form (proposal) for imperviousness test

This Annex is only for information and is not a binding part of this Directive.

Imperviousness Test
Acceptance Order No.

Project:

Building section/line section No.:

Sleeve No. Positive pressure Welder Tested and accepted Date

VL RL 0.2 bar Name Signature

Remarks:
 Page 17 to DVS 2207-5

Annex 5: Content of test and organization of internal and outside supervision

This Annex is only for information and is not a binding part of this Directive.

This Annex to the Directive contains the content of the test for the – DIN 8075 (05/87)
Quality Assurance of PE casing pipe and tubular sleeves and – DIN 16 963 Part 5 (10/89)
corresponding sleeve plates, Table A5-1. The content of the test
for the Quality Assurance of welded joints in fittings and sleeve – GKR Guideline R 9.3.17 (05/92)
joints (welding in the works and on site) is also specified; Table
A5-2. It isbased on the requirements of the official product In Tables A5-1 and A5-2 recommendations for a Quality
standards and guidelines: Assurance Certificate are given. In the list of obligations of the
– DIN EN 253 (4th draft revision; issued on 1.11.1991 in the TC contractual partners special stipulations can be imposed
107) concerning the tests to be carried out, the scope and frequency.
– DIN EN 448 (pr EN; issued on 1.11.1991 in the TC 107)
Table A5-1. Monitoring tests on semi-finished products (casing pipes and tubular sleeves and sleeve plates); FM = moulding compound, HZ = semi-finished product.

Serial Application Tests Execution as per Requirements as per/ Test/frequency

Item standard, Section values
No. in:
DIN EN DVS Type of tests On On suitability internal outside
253 2207-5 FM HZ test supervision supervision
Page 18 to DVS 2207-5

1 – Technological tests
1.1 5.2.1 – Density of the tube material × DIN 53 479 DIN EN 253, Section 4.2.1.1
E.g. Method A GKR Guideline R 9.3.17
ISO 1183:1987 "A" or "D" > 0.944 g/cm3
1.2 5.2.1 – Melt index, × × DIN 653 735 DVS 2207-5, Section 3
"MFI 190/5" (g/10 minutes) ISO 1133:1981 DIN EN 253, Section 4.2.1.2
GKR Guideline R 9.3.17
Execution of the
For moulding compounds: Execution of the In general twice
tests described
tests described per year1)
a) 0.4. ... 1.3 on each delivery
a) (classes 005 and 010
a) DIN 16 776 T1)
For welded joints:
a) ∆MFI ≤ 0.5
b) MFI(HZ) ≤ MFI (FM) + 0.22)
1.3 4.2.1.3 – Oxidation stability (OIT) × (×) ISO/TR 10 837 DIN EN 253, Section 4.2.1.3 Manufacturer's
GKR Guideline R 9.3.17 certificate per
200°C/> 20 minutes batch

1.4 – if necessary dry loss × GKR Guideline R 9.3.17 GKR Guideline R 9.3.17
> 0.1 % Execution of the
Execution of the In general twice
tests described
1.5 – if necessary homogeneity × × GKR Guideline R 9.3.17 GKR Guideline R 9.3.17 tests described per year1)
on each delivery
Non-homogeneities < 0.02 mm2
Table A5-1. Continuation.

Serial Application Tests Execution as per Requirements as per/ Test/frequency

Item standard, Section values
No. in:
DIN EN DVS Type of tests On On suitability internal outside
253 2207-5 FM HZ test supervision supervision
2 Condition and dimensions
2.1 5.2.3 – Surface condition × DIN 8075 DIN 8075
DIN EN 253 DIN EN 253, Section 4.2.2.4
GKR-Guideline R 9.3.17 GKR-Guideline R 9.3.17
Unacceptable features Continuous
inspection during
2.2 5.2.2 – Dimensional stability × DIN EN 253 DIN EN 253, Section 4.2.2.3 production
GKR-Guideline R 9.3.17 Execution of the In general twice
tests described per year1)
see permissible limits of
deviation
2.3 5.2.4 – Hot storage × DIN EN 253 DIN EN 253, Section 4.2.2.6 Once per week
GKR-Guideline R 9.3.17 GKR-Guideline R 9.3.17
Deformation ≤ 3%
3 Mechanical tests
3.1 4.2.2.5 – Elongation at tear in the × DVS 2203-2 DIN EN 253, Section 4.2.2.5 Once per week Generally twice
tensile test ISO/DIS 6259, Section 1.2 GKR Guideline R 9.3.17 per year1)
DIN 53 455
≤ 350%
Test speed = 100 mm/min
3.2 5.2.5 – Long-term internal ×3) (×) DIN 8075 DIN EN 253, Section 4.2.1.4 Once per week, Generally twice
pressure test ISO 1167 if stipulated in per year, if
Execution of the
detail stipulated in
tests described
detail1)
3.3 5.2.6 6.4 Tensile creep test in the × × DVS 2203-4 DIN EN 253, Section 4.2.2.7 Four times per Generally twice
wetting agent bath (ISO/DIS 6259 Section GKR-Guideline R 9.3.17 year per year1)
1.2) > 1500 h in the water bath with
2% wetting agent at 80°C;
= 4.0 N/mm2

Explanations:
1) Inspection of the execution and the indications of the internal supervision; if necessary taking of samples for laboratory tests
2) HZ = result on the semi-finished product. FM = result on the moulding compound (pellets)
3) As type test on the extruded specimen tube and as alternative to the tensile creep test in product supervision.

x Execution of the test described.

(X) Execution, if stipulated in detail
a Per machine, dimension, type of compound, or per per production run
b At least per type of compound, machine and group diameter once per year.
Page 19 to DVS 2207-5
Table A5-2. Monitoring tests on welded joints (works and site welds)

Consecutive Application standard, Type of tests Execution as per Requirements Test/frequency

item No. Section in: as per Process Workshop welds Site welds
tests
DIN EN DVS 2207-5 welding outside welding outside
253 (448) supervisor supervision supervisor supervision
Page 20 to DVS 2207-5

1 – 7.1 Visual examination Visual inspection DVS 2207-5, 100% 100%

Section 7.1
2 – 6.1 Short-term tensile test DVS 2203-2 DVS 2207-5,
DN 53 455 Section 7.2
As part of the As part of the
3 – 6.2 Technological bending DIN 2203-5 DVS 2207-5, welder and welder and
test DIN 2207-5, Section 6.2.1 Section 7.2 Execution work work
In general In general
of the examinationsb) examinationsb)
4 – 6.3 anual peel test DIN 2207-5, Section 6.3.1 DVS 2207-5, twice per twice per
tests
(alternative to Item 3) Section 6.3.2 year1) year1)
described
5 – 6.4 Tensile creep test in DVS 2203-4 DVS 2207-5, Four times per
wetting agent bath DVS 2207-5, Section 6.4 Section 7.3 yeara)
DIN 53 444
6 – 6.5 Imperviousness test DVS 2207-5, Section 6.5 DVS 2207-5, 10 ... 20% 100%
Section 7.4

Explanations:
1) Inspection of the execution and the indications of the internal supervision; if necessary taking of samples for laboratory tests
a) At least for each compound type, machine and diameter group once per year
b) Per method, type of material and welding machine
Welder examinations based on DVS 2212
Project-related work tests at the beginning of work; at least half yearly
 Page 21 to DVS 2207-5

Annex 6: Determination of the time factor and a fictitious joining factor for a welded joint
This Annex is only for information and is not a binding part of this Directive.

If creep tests are only carried out under one test stress (for 2. The slope of the curve of the single-axis tensile creep test cor-
example where σ = 4.0 N/mm2), from the results for the base responds in its slope to the curves of the multi-axis long-term
material and the welding specimens only the ratio of the internal pressure tests to DIN 8075; shift of position only on
evaluated times-to-failure (geometrical mean value "XG") can be the time axis.
formed and as the time factor
3. The slope of the curves of welded specimens corresponds to
x G(S) the slope of the base material specimens (parallel trend). Ex-
f s(t) = ------------
-
x G(B) perience has shown that this is only applicable to high quality
butt joints!
be specified.
In the example in Fig.A6-1 the fictitious joining factor is
This time factor is not identical with the joint factor (fs) calculated
from the significance ratio of the stresses. f′ s ( σ ) = 2,0/4,0 = 0,5
If nevertheless – in the absence of basic curves for the tube
material from tensile creep tests – a comparison factor is formed The time factor from the results of the tensile creep test works out
by including known long-term internal pressure curves (for at
example the minimum value curves from DIN 8075) for PE-HD
tubes, this is based on the following assumed conditions: f s ( t ) = 67/1500 = 0,045
1. The long-term internal pressure curves of the casing pipes
correspond in their slope to the minimum curves of DIN 8075. This fictitious joining factor cannot be used as a calculation value.
Comparative stress in N/mm2 is the long-term internal pressure test

Applied stress
in the tests R
As

ef
er
su

en
m

ce
pt
io

sp
n:

ec
w

im
el
di

en
ng

Z-
sp

S-
ec

Z-
im

V
(8
en

0o
cu

)
rv
e

Time-to-failure in years

Time-to-failure in hours
Figure A6-1. Formation of a fictitious joining factor f′s(σ ) from test results of the tensile creep test (Z-S-Z-V) for only one test stress; for example
σ = 4.0 N/mm2.
Page 22 to DVS 2207-5

Annex 7: Stressing of welding sleeves in plastic jacket pipes

This Annex is only for information and is not a binding part of this Directive.

Like the PE-casing pipes, the welding sleeves are exposed to The calculations have been carried out taking into account the
mechanical loads. The stresses are caused by relaxation with temperature, using values of E (σ = 0.75 N/mm2
and 1 N/mm²).
– friction in the subsoil
The following conclusions should be drawn:
– possible drag of the sleeve and
– With the usual plastic jacket pipes applications axial stresses
– restricted elongation due to temperature. of max 2 N/mm2 are to be expected in the sleeve wall.
Because the level of the mechanical stresses has a critical – In extreme cases stresses of up to 4.5 N/mm2 are also possi-
influence on the working life of the joint, the stresses occurring ble.
are estimated for 3 different cases of loading. The significant
loads are in each case the stresses in the axial direction. – The effect of the drag on the axial stress is small.
Estimates: – sheath friction σR = µ · p -– In the case of the traffic loads, the "parking SLW 60" load re-
presents the most unfavourable stress. Because of the disper-
– drag σSt sion of the load coming from the wheel loads with depth, this
– restricted elongation due load represents the critical load for the sleeve joint when there
– to temperature σT = αT ∆T E is little cover above it. The probability that an SLW 60 will park
over a sleeve is however very remote, because the axle load of
Calculation assumptions: DN 250, Da = 400mm, t = 6 mm an SLW 60 is twice the maximum possible according to the
Case 1: Fitted welding sleeve without drag, Road Traffic Authorization Order.
hü = 60 cm in the expansion buffer, µ = 0.25 – Expansion pads reduce both the sheath friction and the drag
Case 2: Welding sleeve with high drag, loads and increase the stress due to restricted thermal expan-
hü = 60 cm in the sand bed, µ = 0.5 sion. In all, however, the stress-relieving effect predominates.
This occurs in particular with high mechanical stress (for ex-
Case 3: High drag, parking heavy truck with 60 t ample depth of cover or traffic loads).
(called: SLW 60),
This information is at present under discussion in the specialist
hü = 1.5 m in the sand bed, µ = 0.5.
circles. The calculations based on other hypotheses and
The results of the guide calculations should be taken from Table assumptions lead to different results, but are of the same order of
A7-1. magnitude.

Table A7-1. Axial stresses in the sleeve wall.

σR σST σT σres
[N/mm2] [N/mm2] [N/mm2] [N/mm2]
Case 1 µ = 0.25 0.3 0 approx 1 1.3
σ = 1 N/mm2
T = + 25 oC
E = 120 N/mm2
Case 2 µ = 0.5 0.6 0.2 approx 0.8 1.6
σ = 0.75 N/mm2
T = + 30 oC
E = 180 N/mm2
Case 3 µ = 0.5 2.7 0.7 approx 0.8 4.2
σ = 0.75 N/mm2
T = + 30 oC
E = 180 N/mm2