Solenoid valve including independently movable pilot plunger head

A solenoid valve, which is disposed in a flow path that extends from a high pressure vessel to open or close the flow path, the solenoid valve comprising:

• a main seat including a hole so that gas flows into the solenoid valve through the hole of the main seat;
• a main plunger configured to be in contact with the main seat;
• a pilot plunger, which is disposed at a top surface of the main plunger inside the solenoid valve, including a hollow portion therein;
• and
• a pilot plunger head, which disposed inside the pilot plunger, having an apex which is in contact with the main plunger, wherein the pilot plunger head moves independently,
• wherein the pilot plunger is movable inside the solenoid valve, and the pilot plunger head is movable inside the hollow portion of the pilot plunger,
• wherein the pilot plunger head and the pilot plunger separately move from each other,
• wherein the apex is arranged at a front end of the pilot plunger head,
• wherein the apex of the pilot plunger head is in contact with a main plunger flow path of the main plunger,
• wherein the solenoid valve further includes a spring attached to a rear end of the pilot plunger head toward the opposite direction to the main plunger and disposed inside the hollow portion, and
• wherein the pilot plunger head is arranged and configured to be pushed into the hollow portion of the pilot plunger independently from the pilot plunger according to the apex being impacted by the main plunger.