herald (plural heralds) 1  A messenger, especially one bringing important news. 2  A harbinger, giving signs of things to come. ( 3 heraldry) An official whose speciality is heraldry, especially one between the ranks of pursuivant and king-of-arms. ( entomology) A moth of the species Scoliopteryx libatrix.
a fire nozzle weighs approximately  ten to fifteen pounds.
PSI is determined by orifice size of the nozzle tip and the flow rate (gallons per minute). For labeling purposes, the standard nozzle size for measurement is a #4 orifice. This size delivers 0.4/gpm at 40psi and 4.0/gpm at 4,000psi.As nozzle sizes increase or decrease, PSI fluctuates accordingly.hemicals. Water Pressure-PSI. Water pressure from the pressure washer is measured in pounds per square inch or PSI. This pressure is the amount of force delivered to the surface being cleaned, and is the critical factor in breaking debris from the surface being cleaned.