Resident script pump circulation

[Domoticatorino]

Hi,
I did a resident script that every minute checks the status of 2 valves and when one of them goes ON, a pump has to be start after 5 minutes. 

Instead if valves are both OFF pump has to be stop immediately.

Considering that I have to use a os.sleep() command, I would like to avoid to run many script in parallel.

What do you suggest?

Thanks.