Problem

What is the meaning of the following message?

"The [Reverse Spin Allowed? = False] only works for [Shut Down After Time Delay] pump.  For other pump types, this is always set to True."

Solution

The message in question explains a limitation in that you can only impose a ratchet device (preventing reverse spin) with the "Shut after Time Delay" pump type. For example if you're using the variable speed transient pump type with speed as the control variable, the speed of the impeller is controlled manually by way of the Operating Rule (overriding the "reverse spin allowed" option)

Note that using a ratchet device to prevent reverse spin (with the Shut After Time Delay pump type) is not quite the same thing as a check valve - even if the impeller cannot spin in reverse, water can still pass through the pump in reverse.

If you would like a check valve in your pump, you have a few options. If you do a search for "hammer check valve" in the Hydraulics and Hydrology community, you will find some articles on this subject. For example:

Modeling Reference - Check Valves in Hammer

Modeling a check valve in the pump?