Printer Friendly

Printer Friendly
20929 Bridge Street, Southfield, MI 48033
4121 Brockton Drive SE, Grand Rapids, MI 49512
6200 Baron Drive, Bridgeport, MI 48722
6910 Treeline Drive, Suite A, Brecksville, OH 44141
Phone: (800) 589-6120 - Fax: (248) 354-3710
www.deppmann.com
Serving the industry since 1927
October 10th 2011 ~ Monday Morning Minutes:
Expansion and Compression Tanks – Part 2 by Norman Hall Last week the Monday Morning Minute introduced the expansion and compression tank formula. We described the
numerator as the tank acceptance. The formula is (Ef – Ep) X Vs where Vs is the system volume and (Ef – Ep) is the expansion of the
fluid minus the expansion of pipe. Let’s review some of the required data.
The volume of the system is the most difficult item to calculate. Some drawing design programs will calculate the system
volume for you. Sometimes you have the difficult task of measuring the pipe lengths and the need for a spreadsheet. Bell and Gossett
offers a quick selection program in the ESP-PLUS. This program offers a handy calculator to help with the manual calculations saving
time and money.
click to enlarge
click to download
The expansion of the fluid and pipe is calculated from the fill temperature to the average maximum temperature of the system.
This is often miss-understood. It is not the delta T of the system or the return temperature to the supply temperature. Example:
Assume you have a closed heating system in Cleveland with a supply temperature of 180°F and a return temperature of 150°F. The
average of the design water temperature is 165°F. In a worst case, in the winter, the fill temperature could be 40°F. So the initial
temperature is 40°F and the maximum average temperature is 165°F.
Showing 180°F Supply and 30°F ΔT so
the average temperature is 165°F
Showing 180°F Supply and 2°F ΔT so the
average temperature of the design is 179°F
If the reset system does not work there
could be times when the delta T is very
low. Often the engineer might select
the maximum temperature very near
the design supply temperature. This
will result in a bit of oversizing of the
tank but also provides a measure of
safety factor. Here are snapshots of the
ESP-PLUS program showing both
methods.
Next week we will continue to examine important calculation parameters.
Disclaimer: R. L. Deppmann and it’s affiliates can not be held liable for issues caused by use of the information on this page. While the information comes from many
years of experience and can be a valuable tool, it may not take into account special circumstances in your system and we therefore can not take responsibility for actions
that result from this information. Please feel free to contact us if you do have any questions.
20929 Bridge Street, Southfield, MI 48033
4121 Brockton Drive SE, Grand Rapids, MI 49512
6200 Baron Drive, Bridgeport, MI 48722
6910 Treeline Drive, Suite A, Brecksville, OH 44141
Serving the industry since 1927
Phone: (800) 589-6120 - Fax: (248) 354-3710
www.deppmann.com
Disclaimer: R. L. Deppmann and it’s affiliates can not be held liable for issues caused by use of the information on this page. While the information comes from many
years of experience and can be a valuable tool, it may not take into account special circumstances in your system and we therefore can not take responsibility for actions
that result from this information. Please feel free to contact us if you do have any questions.
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement