Two way fluid switchover valve with crossover protection

Abstract

A valve controls mutual communication between first, second, and third spaces, and includes a first valve seat controlled by a first valve element communicating between the first space and the second space, and a second valve seat controlled by a second valve element communicating between the first space and the third space. The first valve member is biased towards the first valve seat, and the second valve member is biased away from the second valve seat with less biasing force. A temperature sensitive actuator includes first and second actuator members and is supported between the first actuator member bearing on the first valve element and the second actuator member bearing on the second valve element. This actuator, with rise in the temperature of the fluid generally around it, moves the first and second actuator members with respect to one another so as to exert by the first actuator member a force on the first valve member which urges it away from the first valve seat, and so as to exert by the second actuator member an equal force on the second valve member which urges it towards the second valve seat. Thus communication between the first and second spaces is definitely interrupted, before communication commences to be established between the first and third spaces.