What does the following user notification mean: "The Check Valve at this element closes at time xx.xx seconds"
This user notification will occur for three different cases:
1) If there is a check valve element.2) If there is a check valve added to a pipe using the "Has Check Valve?" property field.3) If a check valve is applied to a pump. A check valve can be applied to a pump by setting the property field "Pump Valve Type" to Check Valve. In addition, for the case of a pump startup, if you have set the property field "Time (for valve to operate)" to zero, a check valve will be implied.
Check valves operate when the network hydraulics warrant reverse flow, i.e., when the hydraulic grade at the downstream end is higher than at the upstream end. In any of the cases above, when there is reverse flow or a pressure wave that reflects back toward the downstream side of the different check valves available, you will see a user notification detailing when the check valve closes. The user notification will occur for any time step that it applies, since it is possible for forward flow to reoccur, or for the check valve to reopen.
For more information on check valves and their use in HAMMER, please see this link.
Modeling Reference - Check Valves