Abstract: The calcium hydroxide(Ca) which is flowed into the deteriorated tunnel by groundwater is reacted with carbon dioxide() and the vehicle's exhaust gas (). So its by-products are precipitated at the drainage pipe and these cause the drainage clogging. Most by-products are composed of with calcite from a chemical experiment. The purpose of this study is mainly focused on comparison of attachment on each material of drainage pipe (teflon-coated steel pipe, silicon-Oil coated pipe, acrylic pipe and PVC pipe). The test was progressed to disembogue the CaO aqueous solution and tunnel outflow into each of the pipes. The experimental results show that the most produced scale pipe is PVC material and the followings are Acrylic pipe, Silicon-Oil coating pipe and Teflon coating pipe. But the long-term test results showed that teflon-coated steel pipe had a problem with durability because soil which was contained in the tunnel outflow occurred detachment of coating and corrosion of the steel pipe.

Abstract: The utility model relates to a household PVC (Polyvinyl Chloride) pipe plug-in type greenhouse belonging to the technical field of household cultivation equipment. The household PVC pipe plug-in type greenhouse adopts the technical scheme that a PVC pipe space frame and a plastic membrane (4) are included, wherein the PVC pipe space frame is formed in the way that PVC stand pipes (1) are in plug-in connection with PVC horizontal pipes (2); the PVC pipe space frame is covered with the plastic membrane; and an entrance (6) is provided. The household PVC pipe plug-in type greenhouse is convenient to move, mount and dismount, and is firm and durable; a user can assemble such a greenhouse with an appropriate size according to the house space of the user; and the household PVC pipe plug-in type greenhouse is low in manufacturing cost, is favorable for popularization, and is particularly suitable to be used in families.

Abstract: A soil nutrient vertical migration leaching device comprises a rain supply device and an earth pillar device; the rain supply device comprises a PVC (polyvinyl chloride) cylindrical pipe, valves, a PVC pipe, a slideable overflow port, a hose and a rain distribution nozzle; and the earth pillar device comprises transparent PVC cylindrical pipes, soil sampling points, solution sampling points, solution collection pipes and penetration holes. The system can be used for adjusting and controlling rain intensity, fertilizing intensity, irrigation intensity as well as land utilization.

Abstract: PURPOSE: A device for manufacturing a Polyvinyl Chloride joint pipe is provided to improve pressure resistance by uniformly maintaining the thickness of a bent pipe CONSTITUTION: A device for manufacturing a PVC joint pipe comprises an extruder(100), a mold(200), a cutting device(500), and a cooling unit(300) The extruder extrudes a PVC material The mold is connected to the extruder and molds the PVC material into a pipe shape The cutting device cuts the first molded PVC pipe The cooling unit is installed in the bottom of the mold The cooling pipe of the cooling unit is bent plural times around an extrusion passage

Abstract: The utility model relates to an acrylonitrile-chlorinated-olyethylene-styrol copolymer (ACS)/polyvinyl chloride (PVC) composite pipe, which belongs to the technical field of plastic composite pipelines. The utility model is characterized in that the composite pipe is formed by compounding an ACS material layer (2) and a PVC material layer (1). The ACS material layer (2) of the first kind of composite pipe is positioned at the inner layer and the outer layer, and the PVC material layer (1) is positioned in the middle layer. The ACS material layer (2) of the second kind of composite pipe is positioned in the inner layer, and the PVC material layer (1) is positioned at the outer layer. The ACS material layer (2) of the third kind of composite pipe is positioned at the outer layer, and the PVC material layer (1) is positioned at the inner layer. The utility model greatly improves the performance of the pipe materials on the technology, and the defects of poor weatheability, easy aging, low softening point and the like of the PVC pipe are overcome. The ACS/PVC composite pipe has the excellent weatheability, aging resistance and high temperature resistance and can be widely used for indoor and outdoor water discharge pipes, water supply pipes, electric sleeve pipes and the like on buildings.

Abstract: Cyclic loading of plastic pipe is a known risk factor that can lead to fatigue related failure. While the re-rating of plastic pipe based on cyclic loading is addressed by advisory documents on other continents, there is limited guidance for design engineers in North American practice. Domestic polyvinyl chloride (PVC) and polyethylene (PE) standards include surge allowances above rated working pressure based on limiting values of hoop stress, but only C900 and C905 for PVC pipe include a method for addressing fatigue in design and then only as an informational appendix, not as part of the adopted standard. In this paper, the author uses field measured transient data to develop three classes of cyclic loading that are typical of water and wastewater practice. Various standard design approaches are then applied to the selection of the appropriate pressure class of plastic pipe for each classified transient. Determination of the corresponding dimension ratios allow for the analysis of the transient data in terms of hoop stress. Given sufficient knowledge of the transient conditions in an existing or proposed piping system, the design engineer can not only design for a total number of lifetime cycles, but also reduce risk of fatigue failure by managing the magnitude of repeated stress cycling.

Abstract: The invention discloses a simple and easy hot melting technology for connection of a PVC pipe, in the method, the PVC pipe is connected through hot melting socket, and the method has the following brief process flows: heating up a pipe end to expand, cooling and shaping the pipe end, connecting the pipe line, heating up the pipe end for the second time, and cooling and shaping the pipe end. Gum water is unnecessary for the technology, so that water pollution caused by the gum water is avoided, and the technology is simple, convenient in operation, firm and reliable in connection, low in installation cost, and particularly suitable for home installation of pipes.