Ran across some double solenoid valves and was wondering what is the common practice for these nowadays? My thought is that we used to have quite a few of these 20-30 yrs ago when the signal/system was not that reliable (double voting on the solenoids).

 

Are you sure it's not a dual solenoid on a spool type valve. One coil for open, one coil for close. We use these where we want a valve to "Fail Last"

BTW its possible to just use a short pulse instead of holding the voltage.

Regards
Roy