Delete a Propane Solenoid Safety Valve?

When I operated LPG vehicles to try and thwart evil Mexican gasoline in the 80's the use of a shutoff (vacuum or electric) switch valve was mandatory. I lost track 30 years ago about price and obsolescence but the electric switches would last for many years. They were 12 volt operated and required about one half amp. I used a 24 volt model in my bus with a wind up 12 hour Intermatic Timer. This was in the tropics. Cruising sailboats I worked on had similar smaller valves but the switches heated up to "Ow! ****!" hot.