DESCRIZIONE
The present invention relates to an actuator housing, comprising a mechanical ON/OFF valve arrangement, at least one system pressure connection and at least one ambient pressure connection, said ON/OFF valve arrangement comprising a diaphragm arranged within the housing to have one side exposed to the environment and the other side exposed to an air chamber, wherein said valve is arranged to maintain an OFF-mode when the environmental pressure acting on said diaphragm is below a preset level and maintain an ON-mode when the environmental pressure acting on said diaphragm exceeds said preset level wherein said air chamber is connected to ambient pressure via a valve that is arranged to close said connection when a system pressure is applied that is substantially higher than that in the ambient pressure connection.