communicate with a fluid supply side within a valve housing and solenoid means mounted to the valve housing with a pilot valve interposed between them while defining a pilot chamber below the pilot valve and a second pressure chamber above the pilot valve the pilot chamber communicating with the first pressure chamber and with a fluid discharge side of the valve member the pilot valve actuated by the solenoid means for a relatively smaller displacement allows the main valve member to be actuated to open and close the valve whereby the solenoid means and eventually the entire valve can be minimized in size and any impurity contained in flowing fluid can be prevented from adhering to a movable member in the solenoid means for assuring a highly reliable operation of the valve for a long term application_number US 60847690 A description referring to fig1 3 there is shown a solenoid valve 10 in an embodiment according to the present invention which solenoid valve 10 comprises a valve housing 11 including therein a valve seat 12 and fluid supply and discharge sides or passages 13 and 14 defined on both sides of the valve seat 12 a fluid inlet port 15 connected to the fluid supply side 13 and a fluid discharge port 16 connected to the fluid discharge side 14 in the housing 11 further a main valve member 17 is disposed to be engageable with and disengageable from the valve seat 12 and an elastic diaphragm 18 is provided integral with the main valve member 17 preferably by means of bonding along peripheral part of them these main valve member 17 and diaphragm 18 made integral with each other are disposed so that a fluid pressure in.