Tightness test method for high density polyethylene pipes used in nuclear power plants

Abstract

The invention relates to polyethylene tube test techniques and is intended to provide a tightness test and evaluation method for high-density polyethylene tubes for nuclear power stations, comprising:injecting an HDPE (high-density polyethylene) tube fully with water through a water pump, and increasing the pressure continuously to a test pressure at the controlled pressure increase rate range of40-120 kPa / min; holding the pressure for 4 h, and supplementing water so that the pressure in the tube is maintained to the test pressure; stabilizing the pressure for 1 h, recording pressure data, and drawing a pressure change curve graph; acquiring an actual pressure drop of tightness test according to a ratio of a pressure difference of start and end moments of a stabilized pressure phase to the test pressure; when the actual pressure drop is less than an allowable pressure drop, considering that the tightness test for the HDPE tube is qualified. The method has the advantages that tightness test for the HDPE tube quits using test standards or methods for steel tubes or tubes of other fixed material and structure, and however, a specific acceptance standard for tightness test is made according to the specific tube material and structure and test environments.

Description

technical field [0001] The invention relates to a polyethylene (HDPE) pipe testing technology, in particular to a method for testing the tightness of a high-density polyethylene pipe used in a nuclear power plant. Background technique [0002] With the rapid development of the economy, non-renewable resources such as oil and coal have been exploited and used in large quantities, resulting in aggravated environmental pollution. Therefore, increasing the proportion of clean energy and accelerating the development and construction of nuclear power and other new energy sources have become the general trend. Nuclear power plants typically use seawater as a coolant for peripheral cooling circuits, but seawater is highly corrosive due to its high content of salt and chloride ions. HDPE pipe has excellent corrosion resistance, and has been used in the cooling water pipe system of nuclear power plants such as Callaway in the United States and Sanmen in China. Corrosion on the inner...

AI Technical Summary

Problems solved by technology

Although many theoretical models and research results in the prior art have guaranteed the safety of HDPE pipe systems for nuclear power plants in terms of materials, design, manufacturing, construction inspection and non-destructive testing, the tightness test methods directly used for HDPE pipes for nuclear power plants are still not formed

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