These components are intended for use in LPG kits for small engines, such as generators. LPG is supplied in vapour form to the reducer/vaporiser which feeds the LPG carburettor or mixer.
The Lovato Mini D20 has a vacuum-operated shut-off valve that stops the gas if the engine stalls. The vapour supply should be unregulated, full pressure.
The Gemini KN must be supplied with low-pressure vapour from a 30mbar regulator and will shut off the gas if the engine stalls.
The Tomasetto AT10 Moto has a 12-volt shut-off valve that should be used with a conventional LPG switch to allow priming and to control fuel shut-off. The vapour supply should be unregulated, full pressure.