Conventionally, flow control in accordance with the temperature of the liquid is generally performed by a valve mechanism controlled by electric signals from temperature sensors, or by a pressure tube in which special liquid is filled for transmitting an expansion force or contraction force thereof to a valve mechanism.
However, if those methods are applied to lines for a very small flow formed by pipes having relatively small daimaters, there is unbalance in sizes between the pipes and a controller, resulting in disadvantages in spaces and manufacturing costs.
Such controlling devices have been already developed that initial conditions can be initially set and the initially set conditions or characteristics can be shifted in accordance with the temperature of liquid. These devices have however several problems such as complicated structures and thus high manufacturing costs.
Accordingly, it is an object of the present invention to provide a controller, overcoming the above-noted disadvantages, in which initial conditions can be facilely set, temperature-flow control characteristics based on the initial conditions can be shifted, and the structures are simple, compact, and thus, inexpensive.