Valve device for priming a pump, particularly for coffee making machines

A device for priming a pump comprising:

• a tank storing a water;
• pump means for pumping the water out of said tank along a path and adapted to be controllably activated;
• a first conduit being in flow communication with said pump for conveying the water from said tank;
• heat means downstream from said pump means along said path and in flow communication with said first conduit for heating the water and provided with a calibrating valve controllably evacuating heated water upon reaching a first predetermined pressure set for said calibrating valve from said heat means;
• valve means along said path for passing the water therethrough and formed with a body located between said tank and said heat means, said body receiving said first conduit and a second conduit, said second conduit providing:
• a free passage of the water from said body into said heater upon activating said pump means,
• a flow of the water back from said heat means into said body upon reaching a second predetermined pressure in said heat means which is lower than said first predetermined pressure of said calibrating valve, so that there is no drainage through said calibrating valve;
• and
• a third conduit on said body and operatively connected with said first conduit for discharging the air accumulated therein through said valve means upon actuating of the pump means.