Examining the Behaviour of an Interactive Pipe Liner Under Conditions that May Occur

Rehabilitation # 2004 Milan

The water industry has used renovation techniques to extend the life of its assets for a number of years, beginning with sliplining in the 1970s. These techniques have evolved with time and the use of an interactive liner, where the liner withstands only some of the service loads, with the remainder borne by the host main, is now an established concept. Previous work by the authors has shown that along with the accepted gap-spanning and holebridging criteria, interactive liners are also capable of surviving a circumferential (or ring) failure event, as may be experienced by distribution mains under flexural loading. This paper describes work in which a lined host main, in an as- failed condition is subjected to deflections representative of those which may be seen in service following circumferential fracture. The results of a scoping study suggested that fracture surfaces may experience both longitudinal and transverse displacements post- fracture, leading to tensile and shear displacements of the liner in the vicinity of the host main fracture. A series of experiments were carried out on cast iron host pipes that had been lined with a medium density polyethylene thin- walled liner. These lined pipes contained a simulated transverse fracture. The fracture plane was subjected to varying degrees of shear displacement (up to ~50 mm) and longitudinal separation (up to ~20 mm). The tests were carried out for host/pipe liner systems with a variety of longitudinal gaps. The pipes were held at a pressure of 10 bar for a period of approximately 12 days (˜1,000,000 seconds) to allow creep deformation to take place. The ability of the liner to withstand such deflections over a period of time was hence determined. The aim of the work was to show to what extent displacements such as those discussed above affect the behaviour of a liner under service conditions. The implications of the results of this work on the current design guidelines need further consideration. However, if the outcomes are favourable, and a whole life costing approach shows the merits of such techniques, this could lead to an increased use of interactive liners, with many potential benefits to both the water industry and the customer. Keywords : Interactive Liner, Shear Testing, Mechanical Testing, Host Pipe Fracture.

Please note that the whole article content is available on PPCA website onlySource : 2004 Milan


Related papers

Examining the Performance of Semi-Structural Pipe Liners

Author(s) : Crunkhorn, Smith, Whiter, Mulheron 2001 Munich

Cast iron pipes have been loaded to failure using a four point bending geometry under displacement-controlled loading. Specimens were tested with various liner configurations : unlined, epoxy resin lined or lined with one of two interactive (semi-structural) liners. Some of the pipes also had a circumferential...

Updating Retained Gastket Jointing Technology for PVC Pipes

Author(s) : Smith, Guzowski 1998 Gothenburg

Some forty years ago simple 0 ring joints for PVCu pipes were just being introduced as an alternative to solvent cemented joints. Rubber lip seal type of joints soon followed for both pressure and non pressure applications. Whilst in theory these designs were fine, both styles of joint had operational problems,...

Antioxidant loss in Hot-Water Polyolefin Pipes - Experimental Data and Modelling

Author(s) : Gedde, Smith, Ifwarson, Viebke 1992 Eindhoven

Polyolefin pipes subjected to extensive hoop stresses fail in a ductile manner (stage I). At lower stresses failure is brittle and may in certain cases be preceded by degradation of the polymer (stage 111). Reviewed in this paper are the changes in polymer structure and antioxidant concentration profiles preceding the...

Extrudate Cooling of Medium Density Polyethylene Pipe Sections

Author(s) : Edwards,Ellis, Georghiades,Smith 1982 York

A model is presented for the prediction of cooling rates and temperature profiles during the cooling and solidification of M.D.P.E. pipes. Experimental measurements from an industrial production line are reported and these confirm the predictions of the model. Finally, the model is used to determine the most important...

Case study 1 Plastics underground drainage and access systems, Margam, South Wales

Author(s) : Smith 1972 Southampton

My task in this paper is to convey my experience in the use of uPVC in soil drainage schemes at Port Talbot. I began incorporating plastics drains in building projects in 1966, and owing to experience gained I have continued to specify its use in schemes under my control since that date. One might ask me why I began...

Members of the Association

BOREALISBOROUGEINEOS O&PIRPCKorea Petrochemical IND. Co., LTDLyondellBasellPetroChina Dushanzi Petrochemical CompanyPRIME POLYMERSABICSCG Chemicals & Thai PolyethyleneSinopecTASNEE
TOP