ASCO has a newer series of valves out with Class "H" insulation in the coil winding's. Can handle more heat and won't burn out as quick.
I would never do a control scheme energizing a solenoid on a continuous basis. Prone to failure.
Also, all valves leak that are conveying gas unless you spend some really big bucks, so if you had your emergency O2 system in place, could this not be prone to draining the tank before you really need it? I mean going cheap and not understanding valves when you try to hold them closed with a solenoid.
