Question: what is the difference between normally open and normally closed valve?
Answer: Normally Closed (NC) Fluid is shut off when the coil is de-energized, flows through the valve when the coil is energized . Normally Open (NO) Fluid flows through the valve when the coil is de-energized, shuts off when the coil is energized . ... The valve will operate at pressures from 0 psi to its rated maximum.