Our Monday Morning Minute (MMM) in October outlined the value and need of using Bell and Gossett triple duty valves in variable speed pumping applications. The use of the triple duty valve ports will make it easier to determine the maximum speed to set in the drive. This will assure your client will enjoy maximum energy savings in a properly designed hydronic system. See Triple Duty® valves on your variable speed hydronic pumps to review the MMM on this subject.We’ve received many calls from contractors about the application of triple duty valves in variable speed systems with concern about costs.The Bell and Gossett triple duty valve is a combination non slam check device, balance, and shut off. Let’s assume we are not using the valve for shutoff because there will be an additional butterfly valve on the outlet. The triple duty valve will only be used for determining the excess pressure drop, by measuring across the convenient pressure ports, and as a non-slam check valve.You will find there are times when the installed cost of the B&G triple duty valve is less than the non-slam check with the required pipe diameters. There are other times when the installed cost of the Metraflex non-slam check valve wins out over the B&G triple duty valve.Suggestion on variable speed pumps: If you require a butterfly shut off on the discharge of the triple duty valve, detail the check and shut off but allow the triple duty valve with butterfly valve as a voluntary alternate. The mechanical contractor along with the balancing contractor will determine which method will provide the most cost effective solution.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.
|Metraflex Globe Style Non-Slam Check Valve
|Installed Metraflex Check Valve
|B&G triple duty valve