TT PE - External Polyethylene
The TT PE range from DN 60 to 700 features a high-density polyethylene coating coextruded onto the pipes in the factory.
The TT PE range is intended for use with highly aggressive soils. A high-density polyethylene coating deposited in PAM plants The polyethylene coating is extruded onto the pipes in the Saint-Gobain PAM plants. Internal manufacture ensures rigorous control of the coating application conditions.
Each pipe is tested individually after coating by a "Holiday detector" test in order to check the protective quality of the coating (barrier forming a seal against the external environment). Two manufacturing processes are used, depending on the diameter ranges :
- Coextrusion for DN 60 to 500
- Lateral extrusion for DN 600 and 700
Highly demanding technical specifications
Due to the thickness of its polyethylene layer, the ductile cast iron pipe is fully protected in the most aggressive soils as well as during transport and handling operations.
Thickness of the HDPE layer according to EN 14628
| DN | Minimum thickness μm |
|---|---|
| 60 to 100 | 1800 |
| 125 to 250 | 2000 |
| 300 to 450 | 2200 |
| 500 to 700 | 2500 |
The coating of the TT PE ranges meets highly detailed technical specifications to guarantee outstanding performance.
The TT PE coating complies with European standard EN 14628
Technical specifications of the high-density polyethylene coating according to EN 14628
| N° | Parameter | Requirement Refer to EN 14628 15189 for the precise definition of the test methods |
|---|---|---|
| 1 | Peel strength | 10 N (on zinc plated surface) |
| 2 | Impact strength | Figure 2, category A |
| 3 | Resistance to indentation | <0.3 mm |
| 4 | Elongation at break | >200% |
| 5 | Specific resistance of the coating in 0.1 m NaCl solution | > 108 Ωm2 |
| 6 | Resistance ratio | >0.8 |
| 7 | 7 Thermal ageing, 100 d, 100 °C | <±35% |
| 8 | Light ageing, 100 d, xenon arc radiation | <±35% |
| 9 | Saponification properties of the adhesive | Saponification index < 3 mg KOH/g |
Adhesion of polyethylene is provided on the whole pipe by a regular layer of high performance adhesive specially selected for its durability.
| Property | Standard | Requirement |
|---|---|---|
| Fluidity index | EN ISO 1133 | 0.2g/10 min to 1.0g/10 min |
| Density | EN ISO 1183-1 | 0.910g/cm3 to 0.960g/ cm3 |
Technical specification of the adhesive according to EN 14628
The outer surface of the pipe is completely sprayed with metallic zinc to form a coating of 200 g/m2.
The TT PE coating can be used at permanent operating temperatures up to 50 °C. For high storage temperatures please contact our sales engineers.
| Property | Standard | Requirement |
|---|---|---|
| Viscosity | EN ISO 3219 | > 4000mPa at 180°C Thermosel Brookield Sp 21/5 min-1 |
Specific protection for the junctions
The protective system for the junctions consists of :
- DN 60 to 300 - elastomer sleeve
- DN 350 to 700 - heat-shrink sleeve
If a pipeline with anchored joint (STANDARD Vi, UNIVERSAL Vi or VE, PAMLOCK, STANDARD Ve) is used in saline exterior environment, the elastomer sleeve must be replaced by a heat-shrink sleeve.
Remark
STANDARD Ve and STANDARD V+i anchored joints cannot be used with TT PE pipes, which do not have a rim. STANDARD Vi, UNIVERSAL Vi or VE anchored joints must be used.