Opposing these two is the frictional force between pipe and soil. Let us find these factors first:. I am a Mechanical Engineer turned into a Piping Engineer.
I am very much passionate about blogging and always tried to do unique things. This website is my first venture into the world of blogging with the aim of connecting with other piping engineers around the world. Could you explain better?
In my opinion frictional force calculated by formula 4 shall be multiply by acceleration of gravity g because right now the units are not correct.
Your email address will not be published. Save my name and email in this browser for the next time I comment. The mechanism involves atomic hydrogen which diffuses into a metal Thermal relief valves are also known as thermal safety valves, temperature relief valves, or thermal expansion relief valves. It is a safety device employed in liquid piping and pipeline systems to Skip to content What is Virtual Anchor Length? Join us on Telegram. In my opinion in formula 4 the acceleration of gravity is missing!
Leave a Reply Cancel reply Your email address will not be published. Continue Reading. Soil provides a constant frictional force along a buried steel pipeline. The magnitude of the frictional force depends on the burial depth, pipe weight, soil density, and coefficient of friction between the soil and steel. Therefore, starting from a free end, the total restraint exerted by the soil on the pipe gradually increases until it reaches the fully restrained load at the virtual anchor.
At this point, the naturally occurring forces are balanced with a restraint point. Similarly, moving along the pipe away from the virtual anchor, the pipe expansion becomes gradually minimized until a point of zero expansion is reached indicating the pipe is fully held in place. Axial expansion is calculated by taking the average of the full axial restraint at one end of the pipe and zero restraint at the opposite end of the pipe. When compared to above-ground piping, the total axial expansion at the free end of a buried pipeline is half of the calculated value for a similar scenario involving the above-ground pipe.
In reality, most pipes do not have a totally free end but have some resistance due to soil restraint as the pipe exits the ground and from the connection to above-ground piping. Soils with lower friction resistance or pipes with less depth of cover have longer active lengths and thus have greater expansion at the free end.
Theoretically, there will be pipe movement from the entry point due to thermal expansion. Also, an expansion will be there due to the pressure. Opposing these two is the frictional force between pipe and soil. Let us find these factors first:.
I am a Mechanical Engineer turned into a Piping Engineer. I am very much passionate about blogging and always tried to do unique things. This website is my first venture into the world of blogging with the aim of connecting with other piping engineers around the world. Could you explain better?
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