Pressure behavior of a steel pipeline experiencing creep at normal temperatures

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378297%3A_____%2F18%3A00482444" target="_blank" >RIV/68378297:_____/18:00482444 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1061/(ASCE)AS.1943-5525.0000846" target="_blank" >https://doi.org/10.1061/(ASCE)AS.1943-5525.0000846</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1061/(ASCE)AS.1943-5525.0000846" target="_blank" >10.1061/(ASCE)AS.1943-5525.0000846</a>

Result language

angličtina

Original language name

Pressure behavior of a steel pipeline experiencing creep at normal temperatures

Original language description

This work was motivated by the need for knowledge about the natural decrease in water pressure due to room temperature creep, as distinct from the decrease in pressure caused by leakage in tightness tests of new and/or repaired pipelines. In this context, a case study was conducted regarding the decrease in water pressure in a test pipe with dimensions of 530 mm in outside diameter and 7.8 mm in wall thickness.The system was pressurized to a pressure of 8.985 MPa, after which the water supply was stopped. The test pipe 4 m in length was made from line pipe steel L360NB and was closed by torispherical heads at both ends. Special attention was given to the thermal insulation of the test pipe, ensuring an average temperature of 14.5°C, with variation within 0.1°C over a period of 24 hours. A non-linear ordinary differential equation was derived to describe the time gradient of the water pressure in the test pipe in relation to time, pressure, coefficient of compressibility of water and cross sectional dimensions of the test pipe. The necessary creep parameters and static tensile properties were obtained from specimens manufactured from a ring 30 cm in width taken from the same pipe. The orientation of the specimens was circumferential. The creep tests were performed over a period of 24 hours at ambient temperature. The creep strains were measured by the strain gauge technique, and the effect of temperature variation during the test period was compensated by the use of a compensating strain gauge. The calculated decrease in pressure with time compared quite well with experimental results when the beginning of the pressure decrease was considered two hours after reaching the initial pressure of water and the supply of water was ended. The time period of 2-24 hours follows the recommendations of the CGA standard. A family of 'pressure-time' curves were constructed for a pipe from steel pressurized by water to specific initial pressure levels taken as multiples of the pressure at the yield. These curves cover a time interval of 2 - 24 hours, and they can be used to check the total decrease in water pressure after the tightness test has been completed.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

20306 - Audio engineering, reliability analysis

Project

<a href="/en/project/TE02000162" target="_blank" >TE02000162: Centre of advanced materials and technologies for protection and safety enhancement</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2018

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Aerospace Engineering

ISSN

0893-1321

e-ISSN

—

Volume of the periodical

31

Issue of the periodical within the volume

3

Country of publishing house

US - UNITED STATES

Number of pages

9

Pages from-to

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UT code for WoS article

000427957100014

EID of the result in the Scopus database

2-s2.0-85043536008