Paul - If I am reading this correctly, these are two gravity-fed systems. One with a higher pressure head than the other. But in theory the higher tank will simply drain until its elevation is equal to the lower tank. Or as Charles illustrated, if you have a check valve separating the systems, the higher system will be your source until it drains to the point that they are at equal pressures. In the end, you will have a higher pressure with lower volume; then when the pressures equalize, your volume will increase a little but at the lower tank pressure.
Mark A. Sornsin, P.E. | Karges-Faulconbridge, Inc. | Fire Protection Engineer | Fargo, ND | direct: 701.552.9905 | mobile: 701.371.5759 | http://www.kfiengineers.com -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Paul Cetani Sent: Thursday, February 19, 2015 3:44 PM To: [email protected] Cc: [email protected] Subject: Hydraulic Calculations with two water sources We have an existing fire service (from city water main) feeding hydrants and sprinkler systems. The hydrant at the end of this fire service (hydrant #1) has a static of 50psi, residual of 40psi, and a flow of 750gpm. Our client wants to add an additional water source, via a 200,000 gallon water storage tank at 610 feet about the POC, hoping that the pressure will increase. This storage tank also feeds existing hydrants. The closest hydrant from this water source (hydrant #2) is 50 feet higher in elevation than hydrant #1. Hydrant #2 has a static of 128psi, residual of 8psi, and a flow of 265gpm. To connect the two water sources we are going to run a new fire line 380 lineal feet from hydrant #1 to hydrant #2. We use HydraCalc and it does not allow two separate water sources. Any suggestions on how to determine how much the pressure will be increased, if any? Thanks, Paul B. Cetani <mailto:[email protected]> [email protected] CONFIDENTIALITY NOTICE: This message and any document accompanying it may contain confidential information belonging to the sender. The information is intended only for the use of individual or entity named above. If you are not the intended recipient, or the employee or agent responsible to deliver this message to the intended recipient, you are hereby notified that any disclosure, copying or taking of any action in reliance on the contents of this information is strictly prohibited. If you have received this transmission in error, please immediately notify us by telephone to arrange for return of the documents. _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please visit http://www.symanteccloud.com ______________________________________________________________________ ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please visit http://www.symanteccloud.com ______________________________________________________________________ _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
