Lateral liner wanted: fitted, no crease and tight

Jun 04, 2007

Fitting accuracy, flat surface and leaktightness: the latest IKT-Product-Test "Liners for Laterals" shows which liners fulfil the requirements of the network operators. The marks range from "VERY GOOD" to "POOR". Even the best liner, however, is not always free of malfunction.

Rehabilitation of public and private sewers
The rehabilitation of laterals is becoming increasingly important. With high proportions of extraneous water the cost-intensive rehabilitation only really makes sense if the private sewers are rehabilitated, too. However, laws as well as standards require tight laterals such as §45 NRW-Bauordnung (building regulations North Rhine Westphalia) and DIN 1986. The technical demands on the rehabilitation of laterals with cured-in-place pipes (CIPP) are tremendous. They have far smaller diameters (e. g. DN 150 and smaller) than public collector lines. They are often marked by tight bends up to 90 degrees. Furthermore, in many cases the accessibility is far more limited than in public space. In addition, numerous practical investigations by IKT show that their damage rate is clearly higher than the one of "large" sewers, namely more than 70%. For this reason the NRW Ministry of Environment and 14 sewer network operators wanted to learn more about the suitability of cured-in-place pipes for rehabilitating laterals. They all put the IKT - Institute for Underground Infrastructure in charge of the product test "Liners for laterals". The following network operators participated in the product test:
  • Eigenbetrieb Abwasser
  • Stadt Alsdorf
  • Abwasserwerk Stadt Bergisch Gladbach
  • Stadt Dinslaken
  • Stadtentwässerungsbetrieb Düsseldorf
  • Stadt Gladbeck
  • Stadtentwässerung Göttingen
  • Stadt Hilden
  • Stadtentwässerungsbetriebe Köln AöR
  • Stadt Neuss
  • Niederrheinische Versorgung und Verkehr AG (NVV)
  • Stadtwerke Quickborn
  • Stadt Recklinghausen
  • Entsorgungsbetriebe Warendorf
  • Staatliches Hochbauamt Würzburg
Together with IKT, in the meetings of the steering committee the 14 network operators developed the test programme, selected the test candidates and assessed the test results afterwards.
Liner in the test
The IKT-testers assessed the following eight liners:
  • BendiLiner, EasyLiner GmbH
  • Brawoliner-Fix, KOB KG
  • DrainLiner, epros GmbH
  • DrainPlusliner, epros GmbH
  • Flex-Liner, ALOCIT Chemie GmbH
  • Konudur Homeliner, MC Bauchemie Müller GmbH & Co. KG
  • ProFlex Liner (prototype), VFG AG
  • SoftLiner, EasyLiner GmbH
 
Two other liner manufacturers declined to take part in the product test. For details see result tables.
Test set-up
For the product test the IKT-testers installed laterals with defined damages in the IKT large-scale test facility. Here, they differentiated between two applications:
  • "Standard situation": vitrified clay sewer DN 150 with several bends and damages, rehabilitation via an inspection opening at the ground surface.
  • "Extreme situation": vitrified clay sewer DN 150 with change of dimension and material transition to PVC sewer DN 125 as well as several bends and damages, rehabilitation via an inspection opening at a downpipe.
Test results
Overall result
The winner of the test is the "Brawoliner-Fix“ by KOB with an overall score of "GOOD" in the standard situation and "VERY GOOD" in the extreme situation.

The "Flex-Liner" by ALOCIT Chemie GmbH and the „ProFlex Liner“ by VFG AG, of which only a prototype entered the race, were at the bottom of the list. It could be observed that all test candidates improved the operability of damaged laterals even in extremely bent laterals. Numerous liners, however, presented disappointing results in the very important leaktightness test. Here, only three of the eight tested liners are "GOOD" and better.
Varying quality
All cured-in-place liners showed variations in the liner properties. The IKT-testers noticed these variations in the circumference of the liners, e.g. when measuring the wall thickness, as well as in the length of the liner, e.g. when determining the density. The results of the leaktightness tests according to the APS guideline underline the varying quality of the liners. The dispersion of the results even partially leads to apparent contradictions in the test results. So due to these variations the "Brawoliner-Fix" performs better in the extreme situation ("VERY GOOD") than in the standard situation ("GOOD").
Operation strains with minor influence
The strains introduced during HP cleaning and mechanical cleaning (spiral machine with various fittings) do not noticeably affect the liner quality. The dispersion of the material properties obviously dominates the result of the leaktightness tests. As a consequence of the strains usually only the inner foil is roughened or damaged in some parts. The IKT-testers did not notice changes in the carrier material.
Conflict of aims between operability and tightness
Nearly all tested liners achieved better results in the recovery of operability than in leaktightness. A rehabilitation can be considered successful if the liner does not show any or only few creases and edges. To achieve this the liner material needs to have adequate flexibility especially in bends. This flexibility, however, can oppose the leaktightness of the material.
In the test this became particularly clear when several liner suppliers used different liners for rehabilitating the standard and the extreme situation. So "DrainPlusliner" and "BendiLiner", which were exclusively used in the extreme situation, showed far less creases in bends than the ones used in the standard situation "DrainLiner" and "SoftLiner". But, less creases in these cases led to clear loss in the sealing effect and thus to a worse overall result.
Quality assurance in preparation
Merely the test winner is able to convince in quality assurance with the score "VERY GOOD". Most suppliers provided incomplete or even no documents at all. Partially the documents refer to other materials than used in the test. However, many providers stated that they were currently improving the quality assurance of their products. According to this, three providers applied for a license by the Deutsches Institut für Bautechnik (DIBt) for their liners.
Additional investigations of practice
In addition to their laboratory experiments, the IKT-Product-Testers visited selected construction sites where they inspected the procedures of the rehabilitating personnel and assessed the rehabilitation results. The gained impressions confirm the results gathered at IKT. It was found out that with the procedures liners can be installed under practical conditions (little working space, time pressure). Still the IKT testers found variations in quality, in the length of the liner and its circumference by carrying out random leaktightness tests.
Conclusions
Liners are not only suitable for rehabilitating public sewers, but just as well for rehabilitating smaller laterals. Here, there are numerous constructional challenges, however, under equally high demands on fitting accuracy, flat surfaces and leaktightness. The test shows that there are indeed liners that meet these requirements – but until today still too less. This is why property owners should take a closer look by means of which liner they have their laterals rehabilitated. For liner suppliers with less good results shows the test primarily the potential for improvements. The results clarify which product characteristics still need improvement. Hopefully, the suppliers regard the results as helpful criticism and act in a corresponding way. After all the aim of the independent and neutral IKT-Product-Tests is to build up pressure on the market quickening technical innovations and thus contributing to better products and methods.
Table 1: IKT-Product-Test "Tube Liners for Lateral Pipes":sStandard situation 1
Liner supplier KOB KG epros GmbH MC Bauchemie Müller GmbH & Co. KG EasyLiner GmbH ALOCIT Chemie GmbH VFG AG epros GmbH EasyLiner GmbH Mr. PIPE GmbH Insituform Rohrsanierungstechniken GmbH
Tube liner BRAWOLINER - FIX DrainLiner Konudur Homeliner SoftLiner Flex-Liner ProFlex-Liner (Prototyp) DrainPlusLiner BendiLiner Mr. PIPE-Liner Insituform-Liner
Basic material Polyester high-strengthfabric with PU foil Polyester needle felt with PVC foil Polyester needle felt with PU foil Polyester needle felt with PU foil Knitted polyester fabricwith PVC foil Meshed felt with PU foil - - - -
Resin system Brawo I EPROPOX VIS A4/B4 Konudur 160 PL-XL EasyPox 3008 ALOCIT A 480, B 48.48 or 48.948 Biresin LS - - - -
IKT test mark: standard situation GOOD (1.6) SATISFACTORY (2.6) SATISFACTORY (2.8) SATISFACTORY (3.3) ADEQUATE (4.2) ADEQUATE (4.4) NOT ASSESSED NOT ASSESSED NOT ASSESSED NOT ASSESSED
System test
(weighting 80%)		 good (1.6) good (2.3) good (2.1) adequate (3.7) adequate (4.0) Tube liner was not used

Reason: supplier decided to use the DrainLiner for refurbishment of the standard situation		 Tube liner was not used

Reason: supplier decided to use the SoftLiner for refurbishment of the standard situation		 Participation declined

Supplier's reason: quality already verifiedto an adequate extent by other documents (including DIBt certification)

Complete letter declining participation dated 27.01.2005 included in Annex I of the final report		 Participation declined

Supplier's reason: test conditions outside the specifications of the Insituform-Liner

Complete letter declining participation dated 14.02.2005 in Annex II of the final report
Refurbishment result (60%) Operability2 (40%) 1.7 2.4 2.2 2.9 2.6 2.1
Tightness3 (40%) 1.8 2.7 1.8 3.5 3.5 4.3
Tightness after HP cleaning3 (20%) 1.0 1.0 2.7 1.0 4.3 4.3
Tightness after mechanical cleaning3 (20%) 1.6 2.7 2.1 4.3 4.9 5.4
Quality assurance
(weighting 20%)		 very good (1.5) adequate (4.0)poor (5.5) adequate (4.5) inadequate (6.0) inadequate (6.0)
DIBt certification4 (50%) yes no no no no no
Environment compatibility test certificate submitted for the resin4 (20%) yes5 yes no yes7 no no
Procedure manual and training courses4 (10%) yes yes no no no no
External monitoring4 (10%) yes yes yes yes no no
Evidence of disposability4 (10%) no no no no no no
Construction site investigation practice-orientated installation not carried out6 practice-orientated installation practice-orientated installation practice-orientated installation practice-orientated installation
Additional information: available for 70mm to 200mm 100mm to 300mm 100mm to 300mm 70mm to 1200mm 50mm to 300mm DN 70 to DN 200
Recommended improvements Reduce fluctuations in the liner properties Reduce fluctuations in the liner properties; extend DIBt certification to include the used resin system Reduce fluctuations in the liner properties; improve quality assurance Reduce fluctuations in the liner properties; improve tightness and quality assurance Reduce fluctuations in the liner properties; improve tightness and quality assurance Reduce fluctuations in the liner properties; improve tightness and quality assurance
1 "Standard situation" refers to the geometry of the lateral pipe.

2 Assessment of the operability through visual inspection of the refurbished standard situation by the sewage network operators: 100 points = 1.0 to 0 points = 6.0; marks depicted by a linear function.

3 Assessment: 100% tightness tests passed according to APS guideline = 1.0 to 0% tightness tests passed according to APS guideline = 6.0; marks depicted by a linear function.

4 Assessment: present = yes, not present = no; certifications/certificates/verifications must be valid for the materials used in the test.

5 According to the DIBt certification, a PE protective tube is to be used between the liner impregnated with resin and the pipe being refurbished when using the refurbishment method in areas saturated with ground water.

6 The liner was not used by the participating sewage network operators at the point in time of the site tests; the liner supplier could not name a site either. The installation procedure corresponds basically to that used for the DrainPlusliner.

7 Test certificate of the Hygiene Institute of the Ruhr area dated 1 August 2002: "Given the clear smell and taste contamination of the test water, it is advisable as a precaution to refrain from using in direct drinking water catchment areas (protection zone I) and in protection zone II"..." In our opinion[there] are no objections to using the material "EasyPox" in areas with groundwater contact, as long as these are above the saturated zone and outside drinking water protection zone II".

8 Both B-components (hardeners) 48.48 resp. 48.94 were available and were used.

Assessment key for the test results: very good = 1.0 – 1.5, good = 1.6 – 2.5, satisfactory = 2.6 – 3.5, adequate = 3.6 – 4.5, poor = 4.6 – 5.5, inadequate = 5.6 – 6.0.
Table 2: IKT-Product-Test "Tube Liners for Lateral Pipes": extreme situation 1
Liner supplier KOB KG MC Bauchemie Müller GmbH & Co. KG epros GmbH EasyLiner GmbH VFG AG ALOCIT Chemie GmbH epros GmbH EasyLiner GmbH Mr. PIPE GmbH Insituform Rohrsanierungstechniken GmbH
Tube liner BRAWOLINER - FIX Konudur Homeliner DrainPlusLiner BendiLiner ProFlex-Liner (Prototyp) Flex-Liner DrainLiner SoftLiner Mr. PIPE-Liner Insituform-Liner
Basic material Polyester high-strength fabric with PU foil Polyester needle felt with PU foil Polyester needle felt with PU foil Polyester needle felt with PU foil Meshed felt with PU foil Knitted polyester fabricwith PVC foil - - - -
Resin system Brawo I Konudur 160 PL-XL EPROPOX VIS A4/B4 EasyPox 3008 Biresin LS ALOCIT A 480, B 48.48 or 48.945 - - - -
IKT test mark: extreme situation VERY GOOD (1.3) SATISFACTORY (3.2) ADEQUATE (3.9) ADEQUATE (4.1) POOR (4.6) POOR (5.1) NOT ASSESSED NOT ASSESSED NOT ASSESSED NOT ASSESSED
System test
(weighting 80%)		 very good (1.2) satisfactory (2.6) adequate (3.9) adequate (4.0) adequate (4.3) poor (4.9) Tube liner was not used

Reason: supplier decided to use the DrainPlusliner for refurbishment of the extreme situation		 Tube liner was not used

Reason: supplier decided to use the BendiLiner for refurbishment of the extreme situation		 Participation declined

Supplier's reason: quality already verified to an adequate extent by other documents (including DIBt certification

Complete letter declining participation dated 27.01.2005 included in Annex I of the final report		 Participation declined

Supplier's reason: test conditions outside the specifications of the Insituform-Liner

Complete letter declining participation dated 14.02.2005 in Annex II of the final report
Refurbishment result (60%) Operability2 (40%) 1.9 2.6 1.7 2.4 2.9 3.5
Tightness3 (40%) 1.0 4.3 4.3 6.0 6.0 6.0
Tightness after HP cleaning3 (20%) 1.0 1.0 4.3 1.0 1.0 4.3
Tightness after mechanical cleaning3 (20%) 1.0 1.0 5.2 5.2 6.0 5.2
Quality assurance
(weighting 20%)		 very good (1.5) poor (5.5)adequate (4.0) adequate (4.5) inadequate (6.0) inadequate (6.0)
DIBt certification4 (50%) yes no no no no no
Environment compatibility test certificate submitted for the resin4 (20%) yes6 no yes yes7 no no
Procedure manual and training courses4 (10%) yes no yes no no no
External monitoring4 (10%) yes yes yes yes no no
Evidence of disposability4 (10%) no no no no no no
Construction site investigation practice-orientated installation practice-orientated installation practice-orientated installation practice-orientated installation practice-orientated installation practice-orientated installation
Additional information: available for 70mm to 200mm 100mm to 300mm 100mm to 300mm 100mm to 150mm 70mm to 200mm 50mm to 300mm
Recommended improvements Reduce fluctuations in the liner properties Reduce fluctuations in the liner properties; improve quality assurance Reduce fluctuations in the liner properties; improve tightness; extend DIBt certification to include the used resinsystem Reduce fluctuations in the liner properties; improve tightness and quality assurance Reduce fluctuations in the liner properties; improve tightness and quality assurance Reduce fluctuations in the liner properties; improve tightness and quality assurance
1 "Extreme situation" refers to the geometry of the lateral pipe.

2 Assessment of the operability through visual inspection of the refurbished standard situation by the sewage network operators: 100 points = 1.0 to 0 points = 6.0; marks depicted by a linear function.

3 Assessment: 100% tightness tests passed according to APS guideline = 1.0 to 0% tightness tests passed according to APS guideline = 6.0; marks depicted by a linear function.

4 Assessment: present = yes, not present = no; certifications/certificates/verifications must be valid for the materials used in the test.

5 Both B-components (hardeners) 48.48 resp. 48.94 were available and were used.

6 According to the DIBt certification, a PE protective tube is to be used between the liner impregnated with resin and the pipe being refurbished when using the refurbishment method in areas saturated with ground water.

7 Test certificate of the Hygiene Institute of the Ruhr area dated 1 August 2002: "Given the clear smell and taste contamination of the test water, it is advisable as a precaution to refrain from using in direct drinking water catchment areas (protection zone I) and in protection zone II"..." In our opinion [there] are no objections to using the material "EasyPox" in areas with groundwater contact, as long as these are above the saturated zone and outside drinking water protection zone II".

Assessment key for the test results: very good = 1.0 – 1.5, good = 1.6 – 2.5, satisfactory = 2.6 – 3.5, adequate = 3.6 – 4.5, poor = 4.6 – 5.5, inadequate = 5.6 – 6.0.

Contact

Dipl.-Ing. Gunter Kaltenhäuser (IKT – Institute for Underground Infrastructure)

45886 Gelsenkirchen

Phone:

+49 209 17806 47

Fax:

+49 209 17806 88

E-Mail:

info@ikt.de

Internet:

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