Expansion Tank Selection Tips
When we redesigned Bell & Gossett’s ESP-PLUS® tank selection program a few years ago, we sought comments from users about the program. The feedback came back in two camps. One group wanted a simpler program where the engineer could just enter the basic sizing parameters like other manufacturers’ programs. The other group wanted even more design help than offered in the existing ESP-PLUS program. Our solution? Offer both.
Direct Sizing Method
If the engineer knows the tank sizing parameters, he or she can enter them using the direct sizing method. Users who need more guidance in calculating the parameters can choose one of several methods that match their system type. In ESP-PLUS, each system type shows a sample system schematic to help the user answer questions that will lead to a proper tank size. Each of the tank sizing parameters has a help option that guides the user. In addition to tank sizing, you can size any of the hydronic equipment by clicking on that item in the schematic. ESP-PLUS gives you the ability to spec out the entire system including the tank, pressure reducing valve, pressure relief valve, air separator and the new tank purge valve.
Estimating System Volume
If the user doesn’t know the total system volume – a required input for tank sizing – ESP-PLUS offers two methods for estimating the total: Component and Chiller Size. The component method works by entering the water volume for different system components. ESP-PLUS includes calculators to help. As an example, for pipe, a calculator allows you to enter the total length of each of the different pipe diameters. After the user clicks on the ‘Size Tanks’ button, ESP-PLUS will display all the possible tank selections and show their cost ranking. Information screens are available to describe the features of each of the different tank type.
When sizing a new diaphragm or bladder type expansion tank to replace an old compression tank, use the ESP-PLUS program to simplify the process. Just input all of the requisite information – system size,pressure, etc., and ESP-PLUS will help make the selection. And, once you install the new tank, make sure you properly dispose of the old compression tank.
A final report is available that shows each of the components for the air control system. The report includes the proper field settings for tank and fill valve pressures and links to product information and CAD drawings.
ESP-PLUS is available online at www.bellgossett.com and also from ITT. For more information please contact your ITT HVAC Representative or visit www.bellgossett.com