(Continued from vol. 1, page 1062) The term cast-in-place (CIP) describes a method for casting a non-leaking sleeve of polyethylene (PE) around the butted ends of PE pipes while the joint is leaking air at pressures up to 582 kPa. Mold development involved flow-through or vented molds with the latter providing better results with smaller injection charges. Sound sleeves were cast on pipe diameters ranging from 2.5 to 10 cm (1 to 4 in.) SDR. Aged pipe that had been buried for years was successfully joined to new yellow pipe material. Contaminants such as dissolved natural gas in the pipe wall or a solution of anti-static agents generate joints with inclusions or bubbles although strengths were good. The first paper in this series described the basic process that was developed for repair of damaged gas pipes without depressurizing them. In this work, even the unbaked pipe that was saturated with gas produced bubbles rather slowly and only after the casting had been removed from the mold. Future experiments should explore gas evolution when the sleeve is cooled under pressure since this may prevent the bubble layers from forming. (To be continued)
Cast-in-place (CIP) for joining and repairing live, PE, gas lines - II. process development
Vorortgießen für die Verbindung und Instandsetzung von in Betrieb stehenden Polyethylengasleitungen - II. Verfahrensentwicklung
2002
4 Seiten, 9 Bilder, 2 Tabellen, 2 Quellen
Conference paper
English
Cast-in-place (CIP) for joining and repairing live, PE, gas lines - III. repair of holes
Tema Archive | 2002
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