uPVC Pipes Research Articles

Design of water supply system from rivers using artificial intelligence to model water hammer

Water hammer phenomena is one of the most destructive parameters for designing the water supply systems. This study aims to design sewage transfer system resistant to water hammers through the application of artificial intelligence. The intake location was selected with respect to sediment condition and permissible maximum discharge. After that the water pumping system had been designed and the water hammer phenomenon (WHP) was estimated using the Hytran model. Results showed that the combination of rough UPVC pipes and water hammering controlling facilitation can be chosen as the most proper system for designing the desired system. Also, the Hytran model results showed that the maximum pressure was occurred in 96.59 meters distance. On the other hand, using the adaptive neuro-fuzzy inference system (ANFIS) and a hybrid model, ANFIS optimized by particle swarm optimization (PSO), WHP was estimated in the pipes. The results showed that the ANFIS had better performance in estimation of WHP in the UPVC pipes while the ANFIS-PSO was found to be more suitable in metal pipes.

Innovative approach to determine the minimum wall thickness of flexible buried pipes

This paper uses a finite element based approach to provide a comprehensive understanding to the behaviour and the design performance of buried uPVC pipes with different diameters. It also investigates pipes with good and poor haunch support and proposes minimum safe wall thicknesses for these pipes. The results for pipes with good haunch support showed that the maximum pipe wall stress and deformation increase as the diameter increased. The results for pipes with poor haunch support showed an increase in the dependency of the developed vertical displacement on the haunch support as the diameter or the backfill height increased. Additionally, poor haunch support was found to increase the soil pressure, with the effect increasing as the diameter increased. The design of uPVC pipes for both poor and good haunch support was found to be governed by critical buckling. A key outcome is a new design chart for the minimum wall thickness, which enables the robust and economic design of buried uPVC pipes. Importantly, the methodology adopted in this study can also be applied to the design of flexible pipes manufactured from other materials, buried under different conditions and subjected to different loading arrangements.

Proof-of-concept prototype development of the self-propelled capsule system for pipeline inspection

This paper studies the prototype development for the self-propelled capsule system which is driven by autogenous vibrations and impacts under external resistance forces. This project aims for proof-of-concept of its locomotion in pipeline environment in order to mitigate the technical complexities and difficulties brought by current pressure-driven pipeline inspection technologies. Non-smooth multibody dynamics is applied to describe the motion of the capsule system, and two non-smooth nonlinearities, friction and impact, are considered in modelling. The prototype of the self-propelled capsule system driven by a push-type solenoid with a periodically excited rod has been designed to verify the modelling approach. The prototype contains a microcontroller, a power supply, and a wireless control module, which has been tested in a clear uPVC pipe via remote control. Various control parameters, e.g. impact stiffness, frequency and amplitude of excitation, are studied experimentally, and finally, the fastest progression of the system is obtained.

THICKENING OF ALUM SLUDGE USIN FLOATABLE MEDIA FILTER

A pilot scale filter was tested for thickening of alum sludge generated during the production of potable water in a conventional compact water treatment plant (WTP). The alum sludge is produced from coagulation / flocculation / sedimentation processes that are using aluminum sulfate (Alum) (Al2 (SO4)3. 18H2O). The pilot scale was fabricated from scheduled uPVC pipe. The reactor was filled with floatable media (polystyrene) working as filtration media with counter flow concept. The alum sludge was discharged in the pilot scale setup from the sludge holding tank in the WTP using submersible pump. The pilot scale filter was tested at different rate of filtration (ROF) ranged from 25 to 400 m3/m2/d. In addition, different media heights (100 – 800 mm) were investigated to study the efficiency of the sludge thickening. The filter washing rate (ROW) was tested to determine the optimum ROW that will clean the filter. ROW equal to one to four times the ROF were investigated. The efficiency of the sludge thickening was achieved around 30% at the optimum range of ROF that founded in the range of 150 - 200 m3/m2/d and the filtration media height between 400-600 mm. at the optimum operating conditions, the floatable media filter had the ability to thicken the alum sludge and, the turbidity of the water produced after thickening were less than 12 NTU.

Development of In-Pipe Robot D300: Cornering Mechanism

Utilization of robots for in-pipe maintenance considered as one of the most effective ways to improve the pipeline operation. The specific condition and structure of a pipeline system is a challenge for the robots to perform its task. This research aims to assess the characteristic and performance of the in-pipe robot in a 90° pipe elbow. Hence, a prototype of in-pipe robot for 300 mm UPVC pipe diameter (IPR-D300) has been built. The conception of the robot is based on wall-pressed caterpillar type which is suitable for not only horizontal pipeline position, but also vertical and elbows pipeline. This robot is equipped with ultrasonic sensors, high performance microcontroller board and powerful geared motor for travelling in the corner of pipeline. The developed IPR-D300 consist of three independent driving modules that are able to alter the speed according to the pipeline characteristic. The hardware and software of the IPR-D300 performance have been tested and successfully perform the cornering task smoothly. The developed IPR-D300 potentially can be applied for in-pipe cleaning operation especially on centralised sewerage system. As standard pipeline size for sewerage system housing in Malaysia is 200 mm, smaller and robust in-pipe robot will be the future target.

Finite Element Analysis of Buried UPVC Pipe

Background/Objectives: Understanding the mechanics of buried pipes is complicated due to the imprecision in the properties of the soil envelope. This paper deals with the study of behavior of flexible Un-Plasticized Poly Vinyl Chloride pipes buried in loose and dense sand backfill. Methods/Statistical Analysis: A design methodology is proposed for prediction of the performance of pipes using the finite element method ANSYS. The pipe soil interaction under static loading conditions is investigated. Height of the soil above the pipe varies with the ratios of diameter of the pipe. The numerical results are compared with the available values calculated using the theoretical approach Spangler Deflection theory. Findings: Provision of geogrid reinforcement above the crown of buried pipe is suggested to minimize the vertical deflection of buried Un-Plasticized Poly Vinyl Chloride pipes.

Development of Track Wheel for In-pipe Robot Application

At present, the application of pipelines in industries is becoming more severe. The application is not limited for home application only but it can stretch up to thousands of kilometers across countries. Pipelines are used to transport water, sewage, flammable liquid, high pressure gasses and oil. In order to ensure efficient pipelines performance, the pipelines need to undergo routine monitoring, maintenance and repairing activities. However, due to the nature of pipelines that are long, interconnected, and sometimes buried underground or far beneath the sea make it hard to accomplish the tasks. Relying on human labor for the cleaning and maintenance process is not efficient, not safe and not economical. Therefore, there is a strong demand for a robot that can help the cleaning and repairing process in the pipelines. The main aim of this research is to produce an in-pipe robot. This paper will specifically discuss about the development of hardware and software of track wheel for in-pipe robot application. The Caterpillar concept has been chosen to be considered for further development. The Caterpillar that is equipped with special made track wheel is able to move and also climb in pipelines. The scope of this project is limited to 14” inner diameter of UPVC pipe. The development of the wheel track has followed a systematic engineering design process. Experiments have been conducted to validate the software and hardware. As a result, the developed track wheel successfully climbed up to 300 without skidding or slipping. Consequently, the designed track wheel can be considered to be applied as locomotion of the in-pipe robot. The track wheel can be used to move, climb and maneuver the robot in the pipeline smoothly.

Leaching of lead from new unplasticized polyvinyl chloride (uPVC) pipes into drinking water.

Unplasticized polyvinyl chloride (uPVC) pipes have been used in the premise plumbing system due to their high strength, long-term durability, and low cost. uPVC pipes, however, may contain lead due to the use of lead compounds as the stabilizer during the manufacturing process. The release of lead from three locally purchased uPVC pipes was investigated in this study. The effects of various water quality parameters including pH value, temperature, and type of disinfectant on the rate of lead release were examined. The elemental mapping obtained using scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) confirmed the presence of lead on the inner surfaces of the uPVC pipes and their surface lead weight percentages were determined. The leachable lead concentration for each pipe was determined using high strength acidic EDTA solutions (pH 4, EDTA = 100mg/L). Lead leaching experiments using tap water and reconstituted tape water under static conditions showed that the rate of lead release increased with the decreasing pH value and increasing temperature. In the presence of monochloramine, lead release was faster than that in the presence of free chlorine.

Geo-Spatial Information for the Location and Maintenance Management of Water Service Pipelines

This study examined the geo-spatial information needed for locating and maintaining water service pipelines. Geo-spatial information about the components of water service pipelines are a sine qua non for their location above, on or under the surface of the earth as well as the effective preventive maintenance of the entire water service pipelines. The Faculty of Engineering water service network in University of Benin, Benin City, was used as a case study. The geo-spatial data of the components of water service pipelines were acquired using Global Positioning System (GPS) receivers, while the attribute data were acquired using a standard checklist. Thereafter, the geo-spatial data (GPS data) were processed, and all the GPS data acquired in geographic co-ordinates were converted to plane rectangular co-ordinates, based on Minna Datum of Nigeria, using INCA GeoMATRIX software. The rectangular coordinates were exported into Autodesk Land development software, and vector model of the water service infrastructure in digital format was produced. A database was designed and created for geo-spatial and attribute information of various components of water service infrastructure (WSI). The study has revealed the locations of the burst pipes and the control valves that were malfunctioning, where the water pumped from the ground level storage reservoir, ooze out and caused artificial water scarcity in the Faculty of Engineering. The burst pipes were replaced with Unplasticised Polyvinyl Chloride (uPVC) pipes since they are nowadays most preferred for water supply piping. The control valves were also replaced with new ones. The GPS coordinates obtained in this study were used to determine the locations of the various components of water service infrastructure (WSI) in the study area. The geo-spatial and attribute information of hydraulic characteristics of the WSI has facilitated the planning, updating, operation and maintenance management of water service scheme in the study area. Furthermore, the study has provided a dynamic water service scheme of the Faculty of Engineering in digital format, which supersedes the existing, static water service scheme that is difficult to update, maintain and in analogue format. The dynamic water service scheme as well as the geo-spatial information of WSI can be updated and maintained regularly.

Application of High Density Polyethylene Pipe (HDPE) in Same Floor Drainage System

This paper analyses the technology characteristics of HDPE pipes and UPVC pipes that used in drainage. Using a residential building project in Hangzhou as an example, it compares the economic benefits and comprehensive benefits of HDPE pipes with those of UPVC pipes. It concludes that it’s better to use HDPE pipes in same floor drainage system, and the using of HDPE pipes will bring benefits in the promoting of the same floor drainage system.

Lifetime Assessment of Load‐Bearing Polymer Glasses: An Analytical Framework for Ductile Failure

AbstractThe most widespread application of polymers in structural applications is their use as pipe material for e.g., gas distribution systems. Pipes have a design lifetime of typically 50 years, which rules out real‐time lifetime assessment methods. Here, an engineering approach is presented, which makes it possible to predict long‐term ductile failure of loaded glassy polymers based on short‐term tests. The approach is based upon the hypothesis that failure is governed by accumulation of plastic deformation up to a critical strain. A pressure‐modified Eyring relation is employed to calculate the accumulation of plastic strain for any simple loading geometry. It is demonstrated that the approach can produce accurate quantitative time‐to‐failure predictions for loaded PC specimens and uPVC pipe segments.magnified image

An attempt to use scratch tests to predict the residual lifetime of unplasticised poly(vinyl chloride) pipes

This paper reports on a procedure that can potentially predict the residual lifetime of low-pressure uPVC pipes in a non-destructive way. Ageing of these materials is characterised by a change in yield stress and fracture behaviour. The search for a method being able to non-destructively evaluate the yield stress and the fracture behaviour led to the study of scratching of the polymer surface. According to an extensive study by Atkins and Liu, the scratching behaviour is a function of yield stress, fracture toughness and the attack angle of the cutting tool. Experiments reported in this paper give an evaluation of the scratched area as a function of the attack angle for uPVC samples having different ageing times. Existing analyses for metals are adapted for polymer specific properties, such as the pronounced strain rate dependence of yield stress and visco-elastic recovery. The suggested adaptations are successful in the sense that the resulting analysis is capable of describing the forces during scratching and the resulting cross-sectional area of the groove. Although the scratching technique was not able to discriminate between differences in the scratch force or cross-sectional area of the groove of the different ageing times, it was possible to get an estimate of the fracture toughness from the analysis. Therefore, scratching is a promising technique to determine the fracture toughness for ductile materials for which it is difficult to obtain accurate results with conventional techniques.

Multi‐modal acoustic propagation in pipes with arbitrary defects: theory and experiments

Underground sewer systems are prone to flooding incidents caused by obstructions such as sediment deposits and wall deterioration. An efficient method for identifying and characterising these obstructions involves measuring the amplitudes of the reflected and transmitted acoustic normal modes excited by a point source in the sewer pipe. However, the behaviour of higher order modes in relatively large pipe work is often difficult to predict and interpret. In order to provide a greater physical insight into the measured data and to guide future experimental work, theoretical predictions have been developed and validated. The presented theoretical work is based on a finite element method and a mode matching technique. In this paper the predicted and measured sound fields are analysed for up to four acoustic modes reflected from two different obstacles (axisymmetric and non‐axisymmetric) deposited in a 150 mm diameter uPVC pipe.

Effect of UV-Radiation on the Migration of Vinyl Chloride Monomer from Unplasticized PVC Pipes

The effect of direct exposure to UV-radiation on the migration of vinyl chloride monomer (VCM) from unplasticized polyvinyl chloride (uPVC) pipes was investigated using locally manufactured pipes. Specimens 33-cm long were used throughout the research. The investigation was carried out, at different times of exposure to a UV-radiation. The VCM concentration in the water was evaluated using the gas chromatography (GC)/head-space technique. A VCM concentration of 2.3 µg/L (ppb) was detected after 14 days of exposure to the UV-radiation. The initial VCM concentration in the uPVC pipe was calculated and the diffusion coefficient of VCM was expressed as a function of time.

The work of fracture in uniaxial and biaxial oriented unplasticised polyvinylchloride pipes

In oriented unplasticised polyvinylchloride (uPVC) pipes, cracks propagate tangentially rather than through the wall as in conventional pipe. Notched impact, a modified peel test and the specific work of fracture approach have been used to measure fracture toughness of a conventionally extruded, a uniaxially oriented and a biaxially oriented uPVC pipe in different directions. The different failure mode for the oriented pipes was found to result from an order of magnitude increase in the fracture toughness for cracks propagating perpendicular to the orientation direction. Differences in the fracture toughness between the oriented pipes were also related to their molecular orientation.

The essential work of fracture through the wall of a uPVC pipe

The specific essential work of fracture, w(e), has been measured for a relatively thick walled uPVC pipe as a function of position through the wall of the pipe. w(e) was highest at the surface of the pipe and decreased significantly at the centre of the pipe wall. The variation in w(e) through the wall of the pipe correlated with the processing level of the uPVC material as measured by the critical temperature, T-c. The variability in the measured values of w(e) was substantially higher in the centre of the pipe where the processing levels were lower. This was likely to be a result of the variability in the microstructure of the material where poor processing had introduced regions of poor fusion of primary PVC particles. (C) 2002 Kluwer Academic Publishers.

Effect of solar radiation on the migration of vinyl chloride monomer from unplasticized PVC pipes

The effect of direct exposure to solar radiation on the migration of vinyl chloride monomer (VCM) from unplasticized polyvinyl chloride (uPVC) pipes was investigated using locally manufactured and imported pipes. Specimens 33 cm long were used throughout the research. The investigation was carried out, at different times of exposure, by exposing one part of the specimens to the direct sunlight, while keeping the other part in the shade. The VCM concentration in the water was evaluated using the gas chromatography (GC)/head-space technique. A VCM concentration of 2.5 μg/l was detected after 30 days of exposure in direct sunlight. The original initial VCM concentration in the uPVC was predicted, and the diffusion rate of VCM from uPVC pipes was expressed as a function of time.

A two-stage collapsible core for injection moulded plastic parts with internal undercuts

The internal grooved (undercut) features of plastic injection moulded parts are formed by collapsible cores. While collapsible cores have been designed for pipe sizes smaller than 90 mm in diameter, those for larger pipes are custom designed. The objective of this research was to fully automate the design procedure which, for uPVC pipe fittings is laborious and error-prone at present. This paper discusses the design of the four key geometrical features of a two-stage, lever-actuated collapsible core, namely, the number of segments, the path of the retracting segments during demoulding, the minimum angle of taper of the grooved undercut to permit the segments to retract during de-moulding and the prevention of interference between moving components. After these key geometrical features are established, it is then possible to fully automate the design of two-stage, lever-actuated collapsible cores in a CAD system.

Effect of Water Quality Parameters on the Migration of Vinyl Chloride Monomer from Unplasticized PVC Pipes

The migration of vinyl chloride monomer (VCM) from unplasticizedpolyvinyl chloride (uPVC) pipes was investigated using locallymanufactured pipes. Specimens of 33 cm long were used throughoutthe research. The investigation was carried out under differentconditions of water temperature, pH and total dissolved solidsconcentration and at different durations of exposure. The VCMconcentration in the water was evaluated using the gaschromotography (GC)/head-space technique. A VCM concentration ofmore than 2.5 ppb was detected after 30 days of exposure at45 °C. The initial VCM concentration in the uPVC pipewas predicted using equations derived from Fick's first law ofdiffusion. Water tenperature did not affect the migration ofVCM, unless it was raised to high values (i.e. 45 °C).Total dissolved solids (TDS) and pH of water were found toaffect the release of VCM from uPVC pipes. Diffusion rate of VCMwas predicted as a function of pH or TDS values.

Design automation of two-stage collapsible core using design prototype

Internal features such as undercuts in plastic products obstruct the removal of the moulded product and so special moulding tools have to be custom-designed. Since there is a lack of design knowledge of such tools, heuristic knowledge has first to be formalised and then organised into a framework so that the design can be automated. This paper discusses how a functional reasoning approach for the design of a two-stage, lever-actuated collapsible core for the moulding of uPVC pipe fittings with internal undercuts was implemented as design prototypes that were subsequently computer automated. In functional reasoning, a design is represented in a hierarchy of functions and the behaviours that realise the functions. A structure contains specific variables such as the way in which the design should be assembled. Four different types of knowledge bind together function, behaviour and structure. These are relational, qualitative, computational and context knowledge. The design prototype for the collapsible core was implemented in UniGraphics II. The time required to design these moulding tools has been drastically reduced in the plastic injection moulding company with whom this research was jointly undertaken.