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Tender text for sewage pipes made out of Polyethylene

Tender text for sewage pipes made out of Polyethylene

Public and private tenders are carried out to obtain as many comparable offers for the deliveries and services named in the tender as possible. The tendering authority orientates towards national and international requirements. The responsible engineers are facing the challenge to consider technical and economic aspects equally.

During the development of the tender texts a close cooperation with the product manufacturers is useful to integrate latest innovations which the market creates year after year.

Subsequently you will find an exemplary tender text for a sewage pipe made out of modern polyethylene.

 

 

1.

Preamble - Sewer pipe made of PE-HD Helical extruded pipes:
(pipe delivery / pipe installation and welding of pipe-joints)

1.1

Because of existing boundary conditions a High Density Polyethylene of third generation with bimodal molar mass distribution has to be used for all components of the pipe-system. The raw material has to be classified according to ISO 12162 as MRS 10 (PE 100) The raw material has to provide an excellent chemical resistance, abrasion-resistance, impact-strength and flexibility.

 

1.2 Water tightness of the pipe system as well as safety against root penetration, sewage exfiltration, ground water infiltration hast to be guaranteed durably. Therefore all components of the pipe-system have to be welded homogenously. 

1.3 The used PE-HD raw material must be approved for gravity and pressure application - MRS 10 (PE 100). The pipe manufacturer has to provide a certificate for the used raw materials and welding materials according DIN EN 10204 2.2 or equivalent.

1.4 The pipes have to be produced by helical extrusion, made of PE 100, according DIN 16961-1,-2 The pipes, fittings and manholes have to be produced with a coextruded, inspection friendly, yellow inner surface. The pipe production must be inspected by a third-party regularly. The requirements of DIN 16961-2, section 4 must be tested and monitored by permanent internal control. Furthermore a quality-system according ISO 9000 or equivalent should be implemented.

1.5 For all construction of PEHD/PE100 and all welding-joints the DVS Rules and standards, especially DVS 2205 and 2207, have to be considered. Only approved plastic welders are entitled to execute the welding-joints. All welding parameters of Electrofusion-joints must be automatically recorded by the used electrofusion-machine (E-Box 33 or E-Box 44). If for the manufacture of manholes and fittings and other constructions butt-fusion or Extrusion-welding is used, the welding records for Butt-fusion and Extrusion welding must be according DVS 2207-1,-4.

1.6 The preferred welding-procedure for all pipe-joints is the Electrofusion-process. The pipes should provide an integrated Electrofusion-socket and matching spigot-end. A barcode with welding parameters must be labelled on the Electrofusion-socket.

1.7 For installation and tightness-testing of the pipe-system the DIN EN 1610 has to be respected. The workforces at site shall be trained and taught by the pipe-supplier in handling, installation, welding and testing the pipes.

1.8 The minimum required wall-thicknesses for diameters until DN/ID 1200 are defined in EN 13476, for larger diameters DIN 16917 has to be considered. Furthermore the wall-thickness and the wall structure including profile have to fulfil the static requirements during installation and the whole life- time.  The profile of a structured wall has to be placed above the overlapping-zone of the inner wall during production.

1.9 The pipes and manholes have to be calculated for all load-cases during installation and operation. These calculations have to be submitted to the client for verification and acceptance before starting the installation. The structural calculations have to consider DWA A 127, using an adequate software is preferred.

 

1.10 Physical properties of the processing pipe material (as granule)
Property Requirements Test parameters Test methods
Typical density > 930 [kg/m3]
(base material)

Test temperature 23°C

EN ISO 1183

Thermal stability /

oxidation induction time (OIT)

> 30 min Test temperature: 200°C EN 728
Tensile elastic modulus > 1000 MPa EN ISO 527
Flexural creep (3-point) > 1000 MPa Standard climatic conditions DIN 50014 23/50-2 ENISO 899-2
Melt mass-flow rate (MFR)

0.2 < MFR < 0.7

[g/10 min]

The MFR value may deviate by a maximum of +20% from the specified MFR value

Nominal load: 5 [kg]

Test temperature: 190°C

EN ISO 1133

Stress Crack Resistance
ESCR

Alternatively: FNCT 

> 10.000 hrs

500 hrs

ASTM D1693 ESCR, F50

80°C, 4 MPa, 2% Arcopal

ASTM D1693

ISO 16674

Volatile constituents < 350 [mg/kg] EN 12099
Moisture content < 300 [mg/kg] EN ISO 15512
Carbon black content (applies only to black materials) 2 to 2.5  [%]
(by weight)
  ISO 6964
Carbon black dispersion < Grade 3 Test specimen
freely selectable
ISO 18553
Pigment dispersion f) < Grade 3 Test specimen
freely selectable
ISO 18553


2. Tender specification – product items
Product description

Unit

price

Total price

2.1

KrahPipe DN/ID ……….

made of PE 100,

General requirements acc. to EN 13476, DIN 16961 and DIN 16917,

with structured or solid wall, raw material approved for gravity and pressure application, with a coextruded and inspection-friendly inner-surface.
Minimum wall thickness acc. DIN 16961, ring-stiffness according to static requirements, with integrated Electrofusion Socket and spigot

As required in installation lengths up to 6,0 m transported to construction site, properly uploaded, stored, lowered into the trench at a sufficient height and correctly aligned on foundation, have to be according to the installation regulations described in DIN EN 1610 and installation-manual of pipe supplier.

     Welding-Joints have to be according to the manual of the pipe supplier:

-     Electro fusion socket with integrated brass heating wire
in meander-shape, diameter Æ 2 mm ± 3/100)

-     Structural static proof acc. DWA A 127

         safety factor: …

         max.: cover in m .......

         min.:  cover in m ......

         traffic load:  truck .......... 

         max. ground water lever above pipe crown (longtime), in m: ......

         max. ground water lever above pipe crown (short time), in m: .....

         bedding: base group/Dpr ........ %

         ground soil: base group/Dpr ……. %

-     The proofed static calculation has been submitted
before start of installation

........... meter

2.2

KrahPipe - fitting piece DN/ID ........

made out of PE 100, as described at Item 1, as gap closure, with coextruded and inspection friendly inner surface; additional extrusion welding, manually cutting for fitting into trench

pipe lengths ......... m,
incl. cover socket made from PE 100 for extrusion welding

........... pcs.

2.3

KrahPipe - standard manhole DN/ID ………

made of PE 100, according to EN 13598, manhole shaft according to EN 13476, DIN 16961 and 16917, wall structure according to DIN 16917 type A1 or A2, with security steps made of PE, with welded channel, berm and bottom.

All weldings are according to DVS 2205, Static calculation of manhole shaft acc. DWA A 127 by using adequate software. The full design has to consider all requirements for raw material, pipe-design, statics and for welding. 

The joint between upper shaft and concrete slab/lid has to provide adequate sealing-solution, preferred is a telescopic design to avoid direct axial load induction into the manhole shaft. The chosen design has to be considered in the structural calculation

Construction height from pipe sole up to top edge .......... m,

Manhole shaft DN/ID ……..

Manhole height ……… m over pipe crown

Inlet DN/ID  ……

Inlet angle ……°

Outlet DN/ID  ……

Outlet angle ……°

Channel inner diameter ......... mm,

Side flow DN/ID ………

See also Item 1

               ........... pcs

2.4

KrahPipe - tangential manhole DN/ID ………  

made of PE 100, according EN 13598, manhole shaft according to EN 13476, DIN 16961 and 16917, wall structure according to DIN 16917 type A1 or A2, with security steps made of PE, with welded channel, berm and bottom.

Shaft laterally jointed with main pipe

All weldings according to DVS 2205, Static calculation of manhole shaft acc. DWA A 127 by using adequate software. The full design has to consider all requirements for raw material, pipe-design, statics and for welding. 

The joint between upper shaft and concrete slab/lid has to provide adequate sealing-solution, preferred is a telescopic design to avoid direct axial load induction into the manhole shaft. The chosen design has to be considered in the structural calculation

Tangential manholes are recommended for main pipes > DN 1000

Construction height from pipe sole up to top edge .......... m,

Manhole shaft DN ……..

Manhole height ……… m over pipe crown

Inlet DN/ID  ……

Inlet angle ……°

Outlet DN/ID  ……

Outlet angle ……°

Channel inner diameter ......... mm,

Side flow DN/ID ………

See also Item 1

........... pcs

2.5

Segmented bend DN/ID ......., 

made of PE 100, fabricated of pipes, described at Item 1, fulfilling all static requirements, all segment-weldings made by Extrusion-welding or butt-fusion acc. to DVS 2207.
Bend-ends with integrated Electro-socket and spigot.

preferred Radius = 1,5 x DN

......... ° angle

 

                ........... pcs

2.6

Segmented T-branch DN/ID ......., 

made of PE 100, fabricated of pipes, described at Item 1, fulfilling all static requirements, all segment-weldings made by Extrusion-welding or butt-fusion acc. to DVS 2207.
T-ends with integrated Electro-socket and spigot.

Main diameter DN...........

Branch diameter DN...........


......... ° angle of branch

 

                ........... pcs

2.7

Reducer inverted level, DN/ID .......,

made of PE 100, fabricated of pipes, described at Item 1, fulfilling all static requirements, all segment-weldings made by Extrusion-welding or butt-fusion acc. to DVS 2207.
Ends with integrated Electro-socket and spigot.

Main diameter DN...........

reduced diameter DN...........

                ........... pcs

2.8

Wall collar fitting, DN/ID ..........,

made of PE 100, fabricated of solid wall pipes, described at Item 1, with thickened structured wall for axial and radial anchorage in concrete wall, with integrated EPDM puddle flange (tightness-proof up to 1 bar, supplier has to provide independent test-certificate). Puddle flange fixed by stainless steel straps.

 

........... pcs

2.9

HAS House connection fitting, OD ..........made of PE 100,

for house connection, made of 100,

for branch-dimensions OD 125,160,200 and 225 mm

for main pipes DN/ID > 300 mm

installation by using HAS Welding devices only

Installation manual from the pipe supplier has to be respected

               ........... pcs