Metal Oxide Surge Arrestersn Applications in general considerations on protective characteristics Arrester design (station arresters) Configuring arresters electrical data mechanical data
Pressure Surge
Pressure Surge
Pressure Surge
Pressure Surge
Pressure Surge
Pressure Surge
Pressure Surge
Pressure Surge B) Valve closes suddenly
A) Valve open
Shock wave
Liquid flowing steadily
Liquid flowing steadily E-15
Liquid stationary
Pipe support
Valve experiences a large force
C) A time later
Shock wave Liquid flowing steadily
Liquid stationary
High pressure
E-23
Low pressure
Pipe support experiences large force
Liquid stationary Closed valve (or tripped pump)
Cavity growing (vacuum)
Liquid flowing steadily
Pressure Surge
Pressure Surge Barometric leg
Vapour cavity
Pump tripped
A) Just before the strike
Liquid flowing quickly
Air
E-39
Restrictor - orifice
Pressure Surge
Pressure Surge Consequences: High force Simple equation for force caused by passing pressure wave: F = A * dP A = pipe cross-sectional area F = force, N dP = Joukowski pressure rise
