Abstract: A safety and control system for the product outlet valves of a vehicle tank has pneumatically operated valves associated with each product outlet of the tank, control valves are connected to an air reservoir through a charge valve for effecting operation of the outlet valves, the charge valve being of a single shot type for pressurizing a manifold connected to the product outlet valve or valves. The manifold is connected with emergency release valves and a further solenoid operated valve is operatively connected with a gas detector means. With this arrangement either on detection of escaping product vapor by the gas detector or actuation of the emergency release valves pressure in the manifold is vented thereby closing the product outlet valves through release of pressure, the control valves thereafter being inoperative until the charge valve is actuated to re-pressurize the manifold.A system for protecting and also shutting down the vehicle engine is also disclosed.