| 摘要 |
<p>Regions adjacent to butt welded joints between thermoplastic pipes and/or fittings are covered with sleeves thicker than the maximum weld bead. Alternatively the weld bead is machined of and a single sleeve is used to cover both adjacent regions. Sleeves may be longitudinally or helically split to facilitate fitting. Sleeve elements may be of metal, wood, cork or synthetic materials, e.g. polyamides, polyolefins, impact resistant polystyrenes or rubbers, in dense or expanded foams.</p> |
