Vinyl Chloride Pipe Research Articles

Fracture analysis of defect Chlorinated Poly Vinyl Chloride pipes based on burst pressure and prediction their fraction of life

Most Chlorinated Poly Vinyl Chloride (CPVC) resins contain 63-69 % chlorine, in particular those used for the extrusion of plumbing tubes, due to this chlorination of basic PVC, CPVC offers a mixture of corrosion resistance and low installation costs for its main applications requiring service in non-ambient conditions. CPVC replaces copper owing to its economic gain and by virtue of its pressure resistance characteristics. In this article, we have been interested in fracture analysis and damage modeling of CPVC tubes by subject CPVC samples to burst pressure tests. We performed a set of burst tests on virgin and artificially damaged CPVC pipe at different notch lengths, then submitted the specimens to burst pressure tests, in addition to recording the pressure and time during these tests for use in conducting the study. The results of the burst tests were exploited to estimate the damage and reliability of the material, these two parameters allow us to follow the degradation of the pipes used; subsequently, we determined a new relationship between these two parameters through the fraction life. This makes it possible to predict the moment of damage acceleration and to intervene at the right time for engaging predictive maintenance.

Fundamental Investigation of Various Factors Affecting the Occurrence of Solvent Cracking for Unplasticized Poly Vinyl Chloride Pipes in Building Equipment

We investigated the occurrence of solvent cracking in unplasticized polyvinyl chloride pipes using test materials prepared by conventional methods. We confirmed that voids were formed on the inner surface of the pipe at a holding time of 2 weeks under conditions of room temperature (298 K), 1.0 g of applied adhesive, and 4 N/m U-band tightening torque. The voids formed linearly in the circumferential direction at regions in contact with the U-band and linearly in the axial direction at regions not in contact. Environmental agents of tetrahydrofuran (THF), 2-butane, and cyclohexanone were detected during analysis of void regions on the inner surface of the pipe and residual gas in the pipe. The results suggest that the stress generated by tightening of the U-band and the environmental agents affected void generation. Furthermore, stress analysis simulation of the U-band contact region show the presence of tensile stress at regions in contact with the U-band and compressive stress at regions not in contact. The difference in these stresses and the regularity of the molecular arrangement during manufacturing of the pipe likely influences the direction of void generation, which can progress into cracks.

Strength Assessment of PVC Pipes Filled with Geo-Polymer Concrete asS lender Column

Geo-polymer concrete is an inventive and elective development material delivered by the substance activity of inorganic particles as it is made without cement. In this study Geo-polymer concrete is made with a blend of fly ash and GGBS. This paper mainly reports the output of study and analysis on the behavior of the strength of geo-polymer concrete for M40 grade slender columns. The methodology involved examining columns with four varying diameters such as 1″, 2″,3″ and 4″ of Poly Vinyl Chloride pipes as slender columns with a standard length of 20″ in which, firstly pipes were tested empty then columns were filled with 100 percent cement in concrete and later columns filled with Geo-polymer concrete. These columns were placed under axial load in Universal Testing Machine, strength values assessed under a load of compression concrete with 100% cement mix prepared and tested that taken as reference mix and contrasted with Geo- polymer concrete. Load- Deflection characteristics were examined for all trials. It was observed that strength attained by Geo-polymer-based concrete is marginally lesser than that of concrete made with cement.

Fundamental Investigation of Various Factors Affecting the Occurrence of Solvent Cracking for Unplasticized Poly Vinyl Chloride Pipes in Building Equipment

Fundamental Investigation of Various Factors Affecting the Occurrence of Solvent Cracking for Unplasticized Poly Vinyl Chloride Pipes in Building Equipment

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.

Modeling and Fabrication of a Mobile Inspection Microrobot Driven by a Pneumatic Bellows Actuator for Long Pipes

This paper details the modeling and fabrication of an in-pipe mobile inspection microrobot able to move long distances on small diameter pipes using pneumatic and vacuum pressure switched by an electromagnetic valve for driving the microrobot. We propose that the electromagnetic valve be used near the pneumatic actuator to move the distance. A pneumatic pressure of +300kPa and vacuum pressure of -80kPa are supplied to the electromagnetic valve by two air tubes 140m long. The microrobot with four friction rings at both ends of the actuator moves 20m in 15 minutes on vinyl chloride pipe with an inner diameter of 44mm.

ウォータージェットによる水溶性天然ガス井硬質塩化ビニルケーシングパイプのパーフォレーションに関する基礎的研究

Vinyl chloride casing pipes were perforated with high pressure water jet in a pressure vessel to develop an in-situ perforation system. The casing pipes, 73mm in inner diameter and 8mm in thickness, are those used in Chiba Prefecture for natural gas production. Driving pressure of water jet was up to 98.1MPa, and ambient pressure was up to 10MPa which corresponds to the depth of 1, 000m. In addition to a so-called straight nozzle, various horn type nozzles were used to clarify the effects of shape on the performance.The main conclusions obtained in this study are summarized as follows:(1) The vinyl chloride casing pipes can be perforated with high pressure water jet up to the depth of 1, 000m if driving pressure is sufficiently high (98.1MPa).(2) The perforated area becomes maximum at the ambient pressure of 2-3% of the driving pressure.(3) The maximum ambient pressure under which the pipe can be perforated decreases with standoff distance while the perforated area under low ambient pressure increases with standoff distance.(4) The horn type nozzle whose half horn angle is from 15°to 35°is much more effective than the straight nozzle. The half horn angle of 15°is the most effective for the perforation of the casing pipe.(5) The length of horn can be reduced to about four times nozzle diameter without lowering the performance.(6) The perforated area per unit area of nozzle exit increases with nozzle diameter.(7) Cavitation is one of the main mechanisms for perforation of the vinyl chloride pipe under high ambient pressure.

Automatic purification of animal wastewater by dual means of energy‐retaining anaerobic fermentation and ultrafiltration

Abstract For the purpose of purifying animal wastewater and recovering energy during the operation, an automatic bench‐scale unit was manufactured and operated. It consisted of three pieces of an anaerobic fermentation digester, a sedimentation tank and an ultrafiltration module. The digester was equipped with fixed bacteria beds (bioreactor) and tape heaters. The sedimentation tank was equipped with a heat exchanger, through which fresh slurry passed. During automatic operations the slurry samples were taken out before, during and after the operation, and turbidity and organic matter contents were analyzed. Comparing nylon mesh, chips of vinyl chloride pipe and crushed cement blocks, the crushed blocks were recognized best as a fixed bacteria bed. In the operating process, the supernatant fluid in the sedimentation tank was sent to the ultrafiltration module. After filtration a daily reverse cleansing was performed. All the operations worked according to the command programmed in the Controller PL40M III...

Concentration and form of asbestos fibers in tap drinking water contaminated from a water supply pipe with asbestos-cement

The identification and concentration of asbestos fibers in tap drinking water supplied in a central area of Akita Prefecture, Japan, were determined by phase-contrast microscopy and a scanning electron microscope equipped with an energy-dispersive X-ray microanalyzer. The following results were obtained. 1. Asbestos fibers were found in the tap water from two areas in which an asbestos-cement pipe was used for public water supply. The concentrations of asbestos fibers in the tap water were 2.7 x 10(4) to 27.0 x 10(4) fibers per liter of water in area A and 10.0 x 10(4) to 21.0 x 10(4) in area B. On the other hand, no asbestos fiber contamination was observed in tap water of area C, which shared a common water source with area A. A vinyl chloride pipe was used over the entire length of the water supply in route C. 2. Crocidolite was the predominant type of asbestos fiber detected in the tap water. Chrysotile and a mixture of chrysotile and amosite were also observed. 3. Almost all asbestos fibers detected in the tap water possessed the form of thick or sheaved fibers with lengths ranging from ca. 5 to 10 microns. Their shapes were very different from those of asbestos fibers found in the atmosphere. The typical form of the latter is short (ca. 1 micron in length) and needle-like. 4. It was suggested that the contamination of asbestos fibers in the tap water was caused by erosion and peeling off of the inner wall of the asbestos-cement pipe used as a conduit. In order to evaluate the safety of drinking water in Japan, an extensive survey on asbestos-fiber contamination in tap water is necessary.

地中内部ひずみ計測定結果の判定について

In case of landslide investigations, a confirmation of existing depth of slide surface is one of the most essential investigation. For the purpose of pipe-strain gauges are usually used in the most landslide areas in Japan. On the basis of these observational results, the existing depth of slide surface is definited and these data are presented for planning and designing landslide preventive works. However, recently we have been able to see many column diagrams of strain variation which have some unreasonable measured results of those pipe-strain gauges.Thereupon, on the basis of these observational examples, we carried out comparison between the measured results of these pipe-strain gauges and geological column, and measured results by inserting-type-strain meter, examination of the insulation resistance of the circuit including pipe-strain gauges and lead wires, and measurement of the resistance of each strain gauge. Further, we considered causes why such unseasonable column diagrams of strain variation were obtained.As a result of these examinations, the main causes of such unreasonable columns are as follows:1) Scratch or disconnection of lead wires and treatment parts of waterproof and dampproofing of strain gauges when inserting a pipe-strain gauge into a borehole or when pulling out a casing pipe from a borehole.2) Deteriorative phenomena of insulation resistance of lead wires and treatment parts of gauges for a long time.3) Abrasion phenomena of strain gauges from vinyl chloride pipe for long time.