- 13 years of deformation measurement on HDPE- (Hostalen GM 5010) sewer pipe
Author(s) : Gaube, Mueller 1982 York
In the mid-sixties the application of plastics pipes for sewerage and drainage was beginning.At the same time we have started special tests to measure the deformation of HDPE-pipes under the load of different kinds of soil: sand and shluff. It will be reported about the newest results. The use of Hostalen GM 5010 for...
- A Theoretical Approach to the Practical Problems involved in Jointing different PE Grades
Author(s) : Brinken 1982 York
The compatibility of the various PE materials can be theoretically described by four different theories explained in this text. It is shown that the PE types investigated do not differ with respect to disperse and polar surface energies. The applicability of the theories to socket, electro, and butt fusion and their...
- An appraisal of the UK Market for Plastics Pipes
Author(s) : Stevens 1982 York
Consumption data for the UK pipe markets for PVC, LDPE, HDPE and PP are detailed together with comments on their relative importance to each polymer. Historical growth and market developments are discussed and comment is offered on the future of the UK plastics pipe industry with reference to market penetration, new...
- Assessment of the Influence of Processing on Medium-High Density PE Pressure Pipes
Author(s) : Marshall, Taylor, Dickinson 1982 York
A study has been carried out which has sought to establish the influence of processing conditions on the properties of medium and high density polyethylene. Residual stress and fracture toughness measurements have been carried out on hdpe pipe, from which predications of the influence of diameterlwall thickness on the...
- Case History of a GRP Rivercrossing - Design, Manufacture and Installation
Author(s) : Birkenfeld, Tiemersma, Zonneveld 1982 York
The Wilhelmina canal in the Netherlands has to be enlarged. Therefore the present reinforced concrete culvert for tie crossing of the river "De Donye" with the canal does not Eit with the future canal profile. Due to local circumstances GFP was chosen as material. This was the first project in GW installed in the...
- Criteria for High Toughness in UPVC Pressure Pipes
Author(s) : Birch, Marshall 1982 York
The mechanics of failure of uPVC pipe materials have been investigated using fracture mechanics test methods to induce brittle failure. It has been found that brittle failure can be quantified and test procedures have been developed which are capable of being used as quality control methods for classifying pipe. High...
- Data Collection during Pipe Extrusion
Author(s) : Partridge 1982 York
A flexible data collection system for use on pipe extruders or any other continuous process is described. The system offers security of data, easy installation and displays for supervisors and extruder operators. Some of the benefits and uses of this equipment are described.
- Degradation of PVC Plain and Corrugated Pipes due to Weathering Conditions in Egypt
Author(s) : Eleiche 1982 York
Plastics as engineering structural materials are becoming more and more popular in Egypt. In the present paper, the status of the on-going activities on weathering degradation of plastics pipes is presented. Two types of pipes are being considered, namely : (a) PVC plain pipes produced by the National Plastics...
- Design and Manufacture OF GRP Liners and Their Installation
Author(s) : Cooper 1982 York
Deterioration of the sewers in our cities has produced an urgent requirement for a technically satisfactory cost-effective means of renovating or upgrading existing underground services. One of the most successful methods available is the insertion of a preformed liner into the pipeline with the annular gap being...
- Dynamic Testing of GRP Pipe
Author(s) : Houz 1982 York
In GRP pipes cracks develop and grow, leading to weepage af ter prolonged cyclic loading. Simultaneously a gradual decline of elastic properities of the wall can be observed. This process can be described in two ways : as decline of the elastic "constants" of the lamina and as a concurrent growth of many cracks in the...
- Environmental Stress Cracking as a Tool for Evaluating Polyethylene Piping Materials
Author(s) : Lustiger, Markham, Cassady 1982 York
The phenomenon of environmental stress cracking, which occurs when polyethylene is placed under stress until failure in a detergent environment, is beiag studied both as a means of quality control and for determining the relative resistance to sluw crack growth in polyethylene gas pipe. Two techniques used to measure...
- 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...
- Flexible Plastics Pipes for Hot Water, and the Effects of Oxygen Diffusion
Author(s) : Lenman 1982 York
Flexible plastics pipes have found an everincreasing use for hot-water installations. The requirements that these pipes have to fulfil are more rigorous and partly different from traditional requirements. The oxygen permeability of the pipes has been assumed to cause serious functional trouble in sealed...
- Flexible Thermoplastic Pipes buried in Soft Soils
Author(s) : Soini 1982 York
The series of tests dealt with in the paper was carried out under field conditions. These test installations, conducted in connection with actual installations, were realized in such a way that the test conditions and the conclusions from the results would correspond to actual everyday installation practice as...
- Fracture Propagation in Plastics Pipes
Author(s) : Vancombrugge 1982 York
Formation and propagation of brittle fracture as a function of internal pressure and temperature. Information about crack propagation speed. Discussion about influence of residual stresses.
- Fracture Propagation in Polyethylene (PE) Gas Pipes
Author(s) : Greig, Ewing 1982 York
Fracture propagation is a phenomenon in which a long brittle crack runs along the pipeline at high speeds of...
- Gravity Sewage Pipes of UPVC for 10 Years in Use
Author(s) : Vaelimaa 1982 York
During the time 1968 to 1982 uPVC pipes have been introduced and applied for drainage and sewer installations in Finland. Development consists of work for material technics, product standards and...
- Insulated Flexible Plastics Pipes in District Heating
Author(s) : Bontje 1982 York
In the design of district heating systems, as these become increasingly used, there is a trend towards the conveyance of heat over greater distances and its use at lower temperatures. At the same time, more plastic materials are becoming available and being developed for use at higher temperatures. Thermoplastics can...
- Loading Tests on Buried Plastics Pipes to Validate a New Design Method
Author(s) : Reilly, Trott, Crab 1982 York
A series of loading tests on buried plastics pipes has been carried out to validate a new design method, which can be sumarised in a set of design charts. The test programme involved monitoring the response to loading of pipes of different plastics materials, buried in uncompacted sand. The pipes were tested to...
- Measurement of Toughness in Pipe Materials
Author(s) : Gray, Frye 1982 York
Long term failure of plastics pipes is governed by very slow crack propagation. Assessing pipe materials' resistance to this slow growth is time consuming and in the case of recent very tough medium density polyethylenes is difficult using constant load tests. It is shown that fatigue tests can achieve comparative...
- Mechanical Quality of Welds in Polyethylene Pipe Systems
Author(s) : Wolters, Venema 1982 York
The weld strength of some butt welds and extrusion welds in pipeline systems, made of the newer PE types, has been evaluated by means of short-term and long-term tests. Butt welding appears to be a reliable jointing method. Welding strength is almost independent of the heating plate temperature and weldinq pressure. A...
- New Modifications of Chemically Crosslinked Polyolefin Based Pipes
Author(s) : Narkis 1982 York
Continuous high-temperature peroxide crosslinking of polyethylene is now a well-established technology in production lines of cable and wire insulation. A single-stage, highpressure technology where the pipe forming operation and crosslinking reaction take place in the same machine was developed by Thomas Engel & Co....
- Plastic Material for Pipeline Installations
Author(s) : Barber 1982 York
The growing acceptance of polyethylene as a pipeline material is assessed against its background in relining applications. It is compared and contrasted with more traditional materials for water distribution and an attempt is made to introduce realistic cost comparisons taking into account the relevant technical...
- Polybutylene - Selected Material and Property Aspects
Author(s) : Kemp 1982 York
The properties of polybutylene as a pipe material are discussed, with particular reference to creep, bending moment, bending radius, oxygen diffusion, burst hoop stress as a function of time, and lifetime estimation.Its properties are compared with those of polypropylene and cross-linked polyethylene. Polybutylene 1s...
- PVC Pressure Pipes The Importance of Gelation to Ensure
Author(s) : van den Hevel 1982 York
The field performance of PVC pressure pipes is generally acceptable. Yet a substantial international research effort is being devoted to spontaneous brittle failures. A model describing the nature of such failures will be presented. In this model a pipe is considered to be a matrix with defects. To obtain satisfactory...
- Recent Developments in Expansion Joints for Plastic Pipe Systems
Author(s) : Damerham 1982 York
When I chose a title for this paper nearly two years ago I was aware of projects for several new types of telescopic expansion joints, and of new materials being tested in bellows type joints.I therefore believed that by September 1982 sufficient progress would have been made for a report such as this to be of...
- Recent Developments to Overcome Problems with Drain Reconnections in Plastic Sewer Linings
Author(s) : Gale 1982 York
The report outlines the problem that drain connections Wse on small diameter sewer renovation and equimnt development that is taking place to overcome them. The principal topics covered are: the removal of protruding connections prior to relining ; the subsequent re-opening of drains; grouting to make a mth transition...
- Relaxation Modulus of PVC and PEH Sewage Pipes for Evaluation of Long-Term Stiffness
Author(s) : Koski 1982 York
Stress relaxation in PVC and PEH sewage pipes was measured for more than 10 years, and the relaxation data were extrapolated by means of the Findley creep model up to 50 years. The influence of pipe dimensions, as well as that of the degree of deflection in the pipe are being discussed. It has been observed that the...
- Residual Stress in Internally Cooled Pipe
Author(s) : Housz 1982 York
Residual stress in extruded thermoplastics pipe is set up during the cooling process. The stress is compressive at the cooled boundary and tensile at the adiabatic midplane. Stress level increases with the itensity of cooling. A compromise may be sought between process time and stress level.Measurements made on...
- Sealing Systems for PVC Pipes
Author(s) : Magnusson 1982 York
Sealing rings of natural and synthetic rubber have been used for connecting pipes since 1930. When PVC-plastic pipes were introduced in the early years solvent...
- Service Failure Experience of uPVC Pressure Pipes in the Water Industry
Author(s) : Stephens, Gill 1982 York
Due to its link with the Water Industry WRC has been involved with uPVC pipes for many years. Rased on information gathered from several WRC exercises involving detailed evaluation of operational data, research into pipe failures and information from other suitable sources this paper discusses various aspects found by...
- Some factors affecting Toughness in UPVC Pipe Materials
Author(s) : Moore, Stephenson, Whale 1982 York
Short term tests For the evaluation of the toughness of UPVC pipe materials have been examined. A combination of fracture toughness (a fracture mechanics parameter) and tensile yield stress provide an assessment of toughness. These tests have been applied to commercial pipe samples and to laboratory extruded strip. A...
- The Forecast of Polyethylene Pipe and Fitting burst Life using Rate Process Theory
Author(s) : Bragaw 1982 York
A method for predicting the long-term service life or pressure of polyethylene piping system components has been developed based on rate process theory and validated by a nher of statistical tests. Burst data and life predic- tions for joints and fittings nade by seven manufacturers show lives which could not have...
- The Markets for Plastics Pipes in West Germany and the UK
Author(s) : Dudley 1982 York
This paper discusses the existing markets and underlying trends for pipes made of plastics materials within Europe. Especial emphasis is given to the areas known best to the author, the Federal Republic of Germany and the United Kingdom.
- The Performance of Polyethylene Pipe Systems under Internal Fatigue Pressure Loadings
Author(s) : Barker, Bowman, Bevis 1982 York
The influence of the incorporation of injection moulded fittings and the presence of mirror plate butt welded joints on the performance of polyethylene pipe systems has been assessed. Systems have been tested at 79.5OC under, predominantly, internal fatigue pressure loading. Both fittings and butt welded joints have...
- The Strength of HDPE Pipes for the Renovation of Pipelines by Sliplining
Author(s) : Meldt 1982 York
A method of specifying the HDPE pipes to use in renovation is described. The following factors are considered: flow capacity, stress during insertion into straight and non-straight lines, lifting and buckling forces experienced by the lining while the cavity between it and the old pipe is filled. Four sources of...
- Transportation of Solids and Slurries Through Pipelines
Author(s) : Sprecher 1982 York
The bulk transportation of solids is now setting demands vis-2-vis economic and ecological conditions, particularly overland, which traditional methods of transportation can no longer meet. However, transportation by pipeline provides an ideal solution to such problems. Technological advances in regard to this new...
- Transportation of Solids through Plastics Pipes
Author(s) : Meldt 1982 York
Plastic pipes, in particular High Density Polyethylene (HDPE) have found wide acceptance for the hydraulic transportation of bulk materials.This paper discusses the applications of plastic pipes on the basis of the following criteria: strength under internal pressure, abrasion resistance, corrosion resistance, loss...
- Underfloor Heating - The Up-To-Date Heating System
Author(s) : Jirka 1982 York
The successful application of plastics pipes in several fields has contributed to investigate pS- pes of polyolefines for...
- Weathering Behaviour in UPVC Pipes
Author(s) : LeHunt 1982 York
Exposure df UPVC systems in storage and service leads to changes in physical properties with increased exposure periods. A programme of external exposure and artificial accelerated exposure has been undertaken and changes to surface gloss, low speed mechanical properties and colour development monitored.