Specific Gravity

S Davis

Can any one tell me the specific gravity of a 70%-30% water and glycol mix at 130 degrees.

Thanks

S Davis


Apex Radiant Heating

Carl PE_2

http://appserver.ittind.com/software/adv_plus/visc.htm

Oops. That url only works if you have an account set up with B&G. Try this one. There's a table on page 2.

http://www.dow.com/webapps/lit/litorder.asp?filepath=heattrans/pdfs/noreg/180-01312.pdf&pdf=true

hr

What no HDS

software yet! Dow shows .942 for Dowfrost propylene at 130°, 30%

Siggys Fluid Properties calc module shows.. below.

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Mike Kraft_2

Cryo-tek

s.g. of cryo-tek original is 1.04.The newer -100 stuff is 1.054.......water is 1 so the margin between is so sligt @ 30%.I just went to Hercules web site and checked the specs.You may want to try with whose glycol you'll be using.

cheese

PS the temps are @ 60°to 64° as is the s.g. of water in the GPM formula.

S Davis

HDS

Yes I have HDS, so your specific heat of fluid is your specific gravity?

S Davis


Apex Radiant Heating

Mike T., Swampeast MO

Specific Gravity of the Mix Should Be

63 / 61.55 = 1.0236

63 pounds per cubic foot for mix at 130° divided by 61.55 pounds per cubic foot for pure water at 130°.

hr

Be specfic

sg is a relative measure of a fluids density compared with water at a standard temperature. Dows tables use water 68° F. Others seem to use water at 60°?

So to determine the specfic gravity, divide the density of the fluid by the density of water at 68°

So 30% pg at 130°F (63.0) divided by water at 62.1 gives you 1.01.

The number is always very close to one, what exactly are you trying to calc? Seems your final answer will not vary much using 1 or .924 or 1.002

My Grundfos sg table for water from 32° to 290° ranges from 1.002 at 32­F to .924 at 290°F

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Mike T., Swampeast MO

From Density, Specific Weight and Specific Gravity

"Specific Gravity is dimensionless unit defined as the ratio of density of the material to the density of water at a specified temperature. Specific Gravity can be expressed as:

SG = =

S Davis

New Grundfos

I am setting up a system with a variable speed main pump using a differential pressure transducer set to max system head, so as the zones close off it will ramp the pump down.

S Davis


Apex Radiant Heating

hr

Why not have

the pump manufactures help with you the calcs? I know the young engineers at Grundfos, Kansas City branch are certainly capable of answering your questions, and doing the math. They have acess to all the tables and numbers you need to design this type of job.

Hydronic specfic engineers that hang here could figure that out. Siggy is available for design assistence through www.hydronicpros.com. You are getting beyond my design skills with that type of system and questions

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Mike T., Swampeast MO

Just Found Link to Table

Also from "Engineering Tool Box"

SG Table for Water/Glycol Mix"

Note that as the temperature climbs specific gravity decreases and at a faster rate the higher the glycol concentration

Also note it states "as compared to clean water". Again, if super-finicky you need to know clean water at what temperature...