One key feature of solenoid valves is that they have a position that they are always in when de-energized. This position dictates whether the valve is Normally Closed (N/C) or Normally Open (N/O). Normally Closed solenoid valves are closed when no energy is applied, and Normally Open solenoid valves are open when no energy is applied. When activated, a N/C valve will open. Conversely, a N/O valve will close when energized. Because energy must be constantly applied to stay in the energized position, solenoid valves can become hot if run continuously. Many more options are available for Normally Closed Valves, though we do offer several Normally Open valves as well.