Ethylene Glycol Hydrotest 2

[IanMiller]

I have been working on organizing and verifying our hydrotest data. Last week I came across a few test that were performed with a 70:30 mix of water and antifreeze. The method I am using from the Pipeline Rules of Thumb Handbook does not take a mixture like this into account. Being a dumb Mechanical Engineer, about the only thing I know about ethylene glycol is it behaves differently than water. So I'm looking for the specific volume of ethylene Glycol vs temperature and pressure. Or some way to incorporate it into my model. Once I have that though I am a bit uncertain if I can just take a weighted ratio of water to ethylene glycol behavior to get my solution behavior, I really don't think I can. Has anyone else come across this problem?

Thanks
Ian Miller

 

[PeterCl]

Ian
I looked for similar information several years ago, with limited success, coincidentally for a pipeline hydrostatic testing application. I can recall the theoretical pressure variation due to temperature change was significantly greater for ethylene glycol when compared to both fresh and salt water. We were fortunate that our application was in relatively deep water (1200ft+) with small thermal variation over the test period. The technical departments of the major ethylene glycol suppliers may have the data you're looking for.

Good Luck.
PeterCl

 

[mel66]

how does 50% ethylene glycol effect my pump selection?

 

[zdas04]

Ian,
Disposing of hydrotest liquid is a large and growing problem. Every state has some Draconian rules and they're getting worse every year. How are you planning to get rid of your 70-30 mix?

To me that is a bigger question, but if you've worked that out I'd calculate the thermal expansion as though the pipe were smaller (i.e., reduce pipe volume to 70% and calculate the dP due to 100% water, then reduce it to 30% and calculate the dP due to 100% glycol, then add the two results). I don't know that a mass-weighted average would get you close enough. Like Peter said, you can probably get the bulk thermal exapansion coefficient from the manufacturer.

Mel66,
You might have better luck if you start a new thread for your question, changing questions in the middle of a thread gets really confusing.

David Simpson, PE
MuleShoe Engineering

http://www.muleshoe-eng.com

 

[25362]

I came accidentally through this thread and could add, from literature, that at 20 deg C, packed-in water termal expansion results in a pressure increase of 4.5 atm/deg C, whilst EG results in a 17.2 atm/deg C effect.

 

[1969grad]

For glycol properties I use "Gas Treating Chemicals" by Union Carbide. I have an old (1980) hard copy of this publication but would think that this information is now available on the internet.

 

[jmw]

Density and viscosity both change significantly as well as the freezing point. A good source for data on density and viscosity is:

http://www.houghtonchemical.com/fluids/wintrex/

 

[Arcticdesert]

We use DOW chemical DOWFROST proplyene glycol for winter hydrotests and heat traceing. DOW also makes DOWTHERM ethylene glycol, and both have engineering data contained in litature from dow.

http://www.dow.com/webapps/lit/litorder.asp?filepath=heattrans/pdfs/noreg/176-01419.pdf&pdf=true

I have an engineering and operating guide several years old that has more info than the link above. Like wise contacting the manufacture will likely help you get the info to help solve your problem.

Good luck,
Arctic Desert

 

[ercanbaser]

From "1997 ASHRAE Handbook, Fundamentals, Chapter 20" ,
Table 6 Density of Aqueous Solutions of Ethylene Glycol and table 7 may help you.

I can also e-mail these tables if you want.

regards,
Ercan