Cross-linked Wrap-around Heat Shrinkable wrap tape
General
Cross-linked Wrap-around Heat Shrinkable Sleeve on the weld joint shall be long enough for 24” OD pipe so as to overlap onto the mainline coating by a minimum on each side of the weld joint.
The width of Heat Shrinkable Sleeves shall be 450mm
The corrosion Coating is a wrap-around Heat Shrinkable Sleeve, black in color and shall be suitable for an operating temperature of 140ºF in wet conditions.
Sleeve coating
The inner surface of the sleeves shall be coated with a controlled thickness of an adhesive which in combination with the modified Epoxy primer, will bond to and seal to the steel pipe and common yard applied medium temperature yard coatings, such as epoxy.
Backing
The Sleeve and closure backings shall be fabricated from a thermally stabilized, extruded radiation cross-linked heat shrinkable polyethylene. The Backing of the sleeve and closure shall be homogeneous and free from flaws, defects, pinholes, bubbles, cracks and inclusions.
Primer
The primer shall be a solvent free, modified Epoxy type primer, which is applied to cleaned and dry steel surface. When the sleeve coating comes in contact with the liquid primer during installation, a strong bond shall be formed upon full curing time of the system.
Sleeve thickness
The Heat Shrinkable Sleeve shall provide mechanical protection to the epoxy layer and shall seal onto the epoxy layer and the adjacent line coating. It shall have the following minimum thickness:
Backing 0.97mm (after full free recovery)
Backing +adhesive 1.60mm as supplied
2.2mm fully recovered
| First layer | Epoxy primer |
| second layer | Hot melt adhesive |
| Third layer | Crosslinking polyethylene |
| | | Test standard | Unit | 3PE 65 |
| Adhesive | Softening point | ASTM E28 | ℃(℉) | 100 |
| | Lap shear @23℃ | EN12068 | N/cm2 | 450 |
| | Lap shear @23℃ | EN12068 | N/cm2 | 25 |
| Backing | Specific gravity | ASTM D792 | g/cm3 | 95 |
| | Tensile strength | ASTM D638 | MPa (psl) | 24 |
| | Elongation | ASTM D638 | % | 550 |
| | Hardness | ASTM D2240 | Shore D | 55 |
| | Abrasion resistance | ASTM D 1044 | Mg | 35 |
| | Volume resistance | ASTM D257 | Ohm-cm | 1017 |
| | Dielectricvoltage breakdown | ASTM D149 | Kv/mm | 27 |
| Sleeves | Impact | EN12068 | J | >8 |
| | Indentation | EN12068 | mm | 0.1 |
| | Peel adhesion | ASTM D1000 | N/cm | 120 |
| | Peel adhesion | EN12068 | N/cm | >140 |
| | Cathodic disbondment | ASTM G8 | Mm rad | 3 |
| | Water absorption | ASTM D 570 | % | 0.05 |
| | Low Temp.flexbility | ASTM D2671-C | ℃(℉) | >-32(-26) |
| | Fully recovered T thickness | | Mm(mil) | 1.9(77) |
| | Fully recovered L thickness | | Mm(mil) | 2.4(96) |
|
|
Crosslinking Wrap-Arounded Heat Shrinkable Sleeves For Underground Pipe Coating Corrosion Protection Images
|
