When a pre-insulated district heating pipe is joined on site, the joint casing is sealed in two established ways: with a wraparound shrink wrap or with a prefabricated shrink sleeve. Both are EN 489:2009 type-tested, so neither is weaker than the other.
The difference lies in the construction and in which situation each one suits best.
Shrink wrap: Covalence DualSeal RJS-E
The shrink wrap is wound around the joint casing and shrunk with a flame. The backing is cross-linked HDPE polyethylene (PE-X), and the adhesive is a dual system: an anchoring hot-melt adhesive at the edges and a viscoelastic sealant in the centre.
The wrap scales across a wide size range: widths of 155-900 mm and casing pipes of 90-1200 mm. Because the wrap is wound on site, it also adapts to repair work and non-standard dimensions.
Both are EN 489:2009 type-tested, so neither is weaker than the other.Kutistemuhvi ja kutistekalvo
Shrink sleeve: BG Industry
The shrink sleeve is a prefabricated HDPE PE 100 sleeve sealed with butyl mastic; the higher-end versions also include a shrink wrap and foam filling. The joint is weld-free and can be leak-tested.
The sleeves are supplied in standard size classes DN 90-450. When the pipe size matches a standard series, a prefabricated sleeve is a straightforward way to make repeated joints.
PE 100 and PE-X, what is the difference
PE 100 is pipe-grade polyethylene, the same jacket grade as the jacket of the pre-insulated pipe itself. It is the base material of the sleeve.
PE-X is cross-linked polyethylene. Cross-linking gives the wrap a high shrink force and durability, which is essential for the function of a wraparound shrink wrap.
How the choice is made
In practice, three things drive the choice: pipe size, whether it is new-build or repair installation, and the contractor's equipment and accustomed working method.
For a standard-size new line, a prefabricated sleeve is often the fastest. For repairs and a wide size range, the wraparound wrap adapts best. Kampek supplies both from the same Tuusula warehouse, so the choice can be made according to the project rather than availability.
