The H-Factor

Reducing Entropy

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Unblocking a Group of Files

After downloading a file, it is often Blocked. You must right-click on it, pick Properties and then check the Unblock item: But doing a dozen or more files gets old, real fast. I just learned a way to Unblock a batch of files at once. It involves using PowerShell, a Microsoft tool that is a…

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Adding Hanger Types to HydraLIST

If you want to use a new type of hanger, or are a fab shop that gets a job from a contractor that uses a hanger type that you do not have, it is easy to add that new hanger type to your own machine. A hanger is an assembly, and an assembly is just…

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Welcome

Recently our previous blog service (Typepad) ended their business – so, we have a new home. It will take a bit to get images back and displaying properly, but we are working on it! Final pageview count of original Typepad blog: 387,232

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September 2006
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Darcy – Who?

Darcy-Weisbach. It's a phrase you are probably hearing more and more of. What is it? It is a formula for calculating friction loss just like Hazen-Williams. But whereas Hazen-Williams is used for water in sprinkler pipe, Darcy-Weisbach can be used for any liquid (including water, but NFPA 13 does not permit its use).

Its recent popularity is due to new fluids that have been produced for use in antifreeze systems. In order to calculate these systems you will need to know some things about the fluid being used, specifically the Density and the Viscosity. The Density is in the units of lbs per cubic foot (kg per cubic meter) and the Viscosity is the units of centipoise. These need to be entered in the appropriate spots in the calculation dialog box.

D-W

For more information on Darcy-Weisbach vs. Hazen-Williams see a great comparison article from Scott Martorano of The Viking Group in PDF form at: Darcy-Weisbach Article

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