Pressure reported from a water line, gauge or absolute?

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Homework Help Overview

The discussion revolves around the interpretation of pressure measurements in a water line, specifically whether the reported pressure is gauge pressure or absolute pressure. Participants are examining the implications of the units used, particularly in relation to the value of 1630 kPa.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants are questioning the assumption that pressure is reported as absolute unless specified otherwise. There is discussion about the meaning of "psia" and its relation to gauge pressure, with some confusion about unit conversions and the correct interpretation of the problem.

Discussion Status

There is an ongoing exploration of the definitions of gauge and absolute pressure, with some participants providing insights into typical practices regarding pressure measurement. Clarifications have been offered regarding the interpretation of the units, but no consensus has been reached on the initial assumptions of the problem.

Contextual Notes

Participants note that the question does not explicitly specify whether the pressure is gauge or absolute, leading to confusion. The presence of "psia" in the answer box is highlighted as a potentially significant detail that may influence the interpretation.

EastWindBreaks
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Homework Statement


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Homework Equations

The Attempt at a Solution


I thought the pressure in a water line is in gauge pressure, but the solution suggests that 1630 kPa is in absolute pressure, do we always assume absolute pressure unless otherwise specified?
 

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How does the solution imply gauge or absolute? It's simply asking you to change units isn't it?
 
CWatters said:
How does the solution imply gauge or absolute? It's simply asking you to change units isn't it?
I thought psia means psi as in absolute pressure? if it is, then I would need to add 1630 kpa( if its gauge pressure) to atmospheric pressure, which would be 246.42 psi+14.7 psi, but the correct answer is just simply 246.42 psia.
 
EastWindBreaks said:
I thought psia means psi as in absolute pressure? if it is, then I would need to add 1630 kpa( if its gauge pressure) to atmospheric pressure, which would be 246.42 psi+14.7 psi, but the correct answer is just simply 246.42 psia.
A pressure gauge typically gives the pressure in a water line as gauge pressure. So, you are absolutely right in your criticism of question. I would have given the same answer you gave.
 
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Chestermiller said:
A pressure gauge typically gives the pressure in a water line as gauge pressure. So, you are absolutely right in your criticism of question. I would have given the same answer you gave.
haha, I am not sure if i was criticizing the question or just confused, thank you for clarification!
 
I didn't notice the "psia" next to the answer box. The question itself just says psi.
 
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