Finding resulting pressure in a pipe when water is heated

1. Mar 2, 2015

TSN79

I work with pressurized pipe systems, and so I'm looking for some equation that link water temperature and pressure. In other words, when water in a closed system is heated, it expands, and so the static pressure increases. A typical problem will be determining the resulting pressure in a piece of pipe if the water in it is heated from say 5 to 90 degrees. Any ideas?

2. Mar 2, 2015

Staff: Mentor

Does the water fill the pipe, or is there gas also? Can the pipe expand also when heated, or is it just the water?

3. Mar 3, 2015

TSN79

There is only water, usually at 1-5 bars (gauge pressure). We mostly deal with regular steal pipes (SCH 20, 30, 40) up to DN150 so I'm not sure if pipe expansion is a factor to consider?

4. Mar 3, 2015

Staff: Mentor

What is the coefficient of volumetric thermal expansion of steel, and what is the coefficient of volumetric thermal expansion of water?

Chet

5. Mar 3, 2015

TSN79

They can both be found in the link, but I'm still not sure how to apply these values.

http://en.wikipedia.org/wiki/Thermal_expansion#Volume_expansion

6. Mar 3, 2015

Staff: Mentor

I'd like you to be able to figure this out by yourself. I'm prepared to keep you pointing in the right direction.

Please tell me you understanding of the physical meaning of "volumetric coefficient of thermal expansion" and "bulk compressibility"? Understanding of both of these quantities will be necessary to solve your problem. If you aren't sure of their meaning, please look them up, and then get back to me with your understanding. If you have any questions about them, I will be glad to answer them.

Chet