Construction
Polypropylene heat shrink field joint coatings enjoys very good compatibility with the plant applied three-layer polypropylene coated linepipe.
Structure:
The PP heat shrinkable sleeve is consist of irradiation cross-linked and stretched polypropylene backing and modified high shear strength polypropylene adhesive. It formed into pre-cut wrap around sleeve with a separate closure system, and applied on 2-component solvent-free liquid epoxy primer.
The Backing consists of a cross-linked and stretched polypropylene backing which is designed to partially or fully recover with heat from a touch during application. The backing also provides resistance against mechanical damage and UV resistance during construction and in service.
Specification
| Serial No. |
Specification |
Serial No. |
Specification |
| 1 |
FRDPΦ168×500—1.2/1.0 |
7 |
FRDPΦ508×500—1.5/1.0 |
| 2 |
FRDPΦ219×500—1.2/1.0 |
8 |
FRDPΦ529×500—1.5/1.0 |
| 3 |
FRDPΦ273×500—1.2/1.0 |
9 |
FRDPΦ610×500—1.5/1.0 |
| 4 |
FRDPΦ325×500—1.2/1.0 |
10 |
FRDPΦ711×500—1.5/1.0 |
| 5 |
FRDPΦ355×500—1.2/1.0 |
11 |
FRDPΦ813×500—1.5/1.0 |
| 6 |
FRDPΦ426×500—1.5/1.0 |
12 |
FRDPΦ1220×500—1.5/1.0 |
Note:
☑ Closure patch length and thickness are equal to sleeve axial length and thickness, respectively. Enclosure patch width: 120 mm for sleeves Φ168～Φ426 while 150 mm for sleeves > Φ426.
☑ Custom-made is available to meet any customer special demand.
Frequently Asked Questions (FAQ)
Q1: What is the maximum operating temperature for polypropylene heat shrink sleeves?
The polypropylene heat shrink sleeves are designed to protect buried field joints operating at temperatures up to a maximum of 110°C. They are suitable for pipelines that will operate in buried service from ambient temperature to 110°C for a 30-year design life.
Q2: What standards does the FRDP-PP heat shrinkable sleeve comply with?
The FRDP-PP heat shrinkable sleeve not only meets but exceeds the requirements of ISO/DIS 21809-3: Petroleum and Natural Gas Industries — External Coatings for Buried or Submerged Pipelines used in Pipeline Transportation Systems — Part 3: Field Joint Coatings.
Q3: What is the structure of the PP heat shrinkable sleeve?
The PP heat shrinkable sleeve consists of irradiation cross-linked and stretched polypropylene backing and modified high shear strength polypropylene adhesive. It is formed into a pre-cut wrap-around sleeve with a separate closure system, applied on a 2-component solvent-free liquid epoxy primer, forming the same three-layer structure as the factory-applied 3LPP coating.
Q4: What are the available pipe diameter sizes for heat shrink sleeves?
Heat shrink sleeves are available in a wide range of pipe diameters, from Φ168mm up to Φ1220mm. Standard specifications include sizes such as Φ168, Φ219, Φ273, Φ325, Φ355, Φ426, Φ508, Φ529, Φ610, Φ711, Φ813, and Φ1220. Custom-made sizes are also available to meet any special customer requirements.
Q5: What are the key mechanical performance values of the PP backing material?
The PP backing demonstrates excellent mechanical performance: tensile strength ≥30 MPa (ASTM D638), elongation ≥550% (ASTM D638), hardness ≥61 Shore D (ASTM D2240), water absorption ≤0.1% over 24h (ASTM D570), volume resistance ≥2×10¹⁶ Ω.cm (ASTM D257), and dielectric strength ≥25 KV/mm (ASTM D-149). It also passes low temperature brittleness testing at -40°C.
Q6: How does the closure patch sizing work for different sleeve diameters?
The closure patch length and thickness are equal to the sleeve axial length and thickness respectively. For sleeves with diameters ranging from Φ168 to Φ426, the enclosure patch width is 120 mm. For sleeves larger than Φ426, the enclosure patch width is 150 mm. Custom-made configurations are available to meet specific project requirements.
CYCT
