Ageing test device for PE pipes under fluctuating pressure and lifetime prediction method

A technology of aging test and aging device, which is applied in the direction of applying repeated force/pulsation force to test the strength of materials, measuring devices, instruments, etc., which can solve problems such as deviation and achieve low cost effects

CN107367432APending Publication Date: 2017-11-21GUANGZHOU SPECIAL PRESSURE EQUIP INSPECTION & RES INST
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2017-11-21

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Abstract

The invention relates to an ageing test device for PE pipes under fluctuating pressure. A pressure supply device provides gas load of a whole pipe, air pressure in the pipe is adjusted by combined action of a pressure sensor, an electric control valve and a central controller, a pressure injecting and relief process is repeated to form fatigue circulating load, a test pipe section is aged by an ageing device, by the device, research on existing single-factor ageing is changed, various environmental stresses are combined together, and therefore, a laboratory environment which simulates actual working conditions of an urban natural gas pipe is formed. The invention further relates to a lifetime prediction method for the PE pipes under fluctuating pressure. An aged pipe sample is taken out after a specific period, test on mechanical properties and physical and chemical properties is carried out to obtain related data, and change of ageing properties of optional environment temperatures and optional pipes is measured. Compared with an existing method, the lifetime prediction method has the advantages of simplicity, high efficiency and low cost.
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Description

technical field

[0001] The invention relates to the technical field of PE pipeline detection, in particular to an aging test device and a service life prediction method for PE pipelines under fluctuating pressure. Background technique

[0002] Polyethylene (PE) is a high-molecular polymer widely used in the fields of gas transmission and water supply. It has good mechanical properties and excellent corrosion resistance. It has been put into production application in large quantities. However, in the installation and use of polyethylene (PE) pipes, it is inevitable that there will be damage caused by corrosion, microbial decomposition, thermo-oxidative aging and third-party construction reasons. The aging failure problem is particularly noteworthy. However, in recent years, aging research Among them, the fatigue effect caused by the fluctuating gas load on the pipeline during gas transmission under actual working conditions is often ignored, resulting in a large deviation be...

Examples

Embodiment Construction

[0028] see figure 1 , which is a structural schematic diagram of an aging test device for PE pipes under fluctuating pressure in this embodiment. The aging test device includes a compressor 1, a pipeline 2, an oven 6, a first pressure sensor 4, a first electric control valve 3, a second pressure sensor 8, a second electric control valve 9, a central controller 10 and a pressure reducing valve 5.

[0029] The compressor 1 and the oven 6 are connected through a pipeline 2 to form a circulation loop, and the test pipe section 7 is placed in the oven 6 .

[0030] Specifically, the compressor 1 serves as a gas generating device to provide a gas load for the pipeline, and also serves as an air extraction device to ensure that the gas load in the pipeline fluctuates within a certain range. The oven 6 plays the role of heating, providing high-temperature environmental stress to age the test pipe section 7 . A sealing ring is tightly fitted between the pipeline 2 and the oven 6 to e...