To prevent stagnation of a fluid inside by communicating first and second passages with the other opening part from one opening part of a valve seat, communicating a third passage with the other opening part, and disposing the third passage in such a way that the inner peripheral lower face of the third passage is almost flush with the lower end of the other opening part.
Passages 1, 2 are formed pointing vertically, and a passage 3 is formed pointing horizontally. The passages 1, 2 can be communicated with the other opening part 6 from one opening part 5 of a valve seat 4 through a diaphragm 7, and the passage 3 is communicated with the other opening 6. A fluid flowing from the passage 1 or 2 is therefore made to flow from one opening part 5 to the other opening part 6 through the inside of a valve body 8 and to flow to the passage 3. The passage 3 is disposed with its axis shifted from the center axis of the other opening part 6 so that the inner peripheral lower face of the passage 3 is almost flush with the lower end of the other opening part 6. The whole quantity of the fluid flowing from the passage 1 or 2 can therefore flow positively to the passage 3.
YOSHIKAWA KAZUHIRO
MESE HISAYOSHI