Tim Sullivan, P.E. Hubbell, Roth & Clark, Inc.
Outline Pressure Hydraulic Energy and Head Losses System-Pump Curves Concepts of hydraulics as they relate to Operators and Mechanics
Outline Good News Bad News
Outline Formulas & Math
Outline Good News? No Test
Outline Formulas & Math
Pressure Depth Weight Pressure = of x of Water Water
Pressure (ft) 1 ft 2 1 3 0 PSI 4 1 ft 2 ft 2 1 3 0 4 PSI 2 ft 3 ft 2 1 3 0 PSI 4 3 ft
Pressure (in psi)
Pressure (psi per ft) 2.3 ft 2 1 3 0 PSI 4 1 psi 4.6 ft 2 1 3 0 4 PSI 2 psi 6.9 ft 2 1 3 0 PSI 4 3 psi
Pressure (psi per ft) 50 psi 2.3 ft 2 1 3 0 PSI 4 51 psi 4.6 ft 2 1 3 0 4 PSI 52 psi 6.9 ft 2 1 3 0 PSI 4 53 psi
Pressure (Gauge vs Absolute) psi g & psi a psi a = psi g + 14.7 psi
Pressure (Gauge vs Absolute) 14.7 psi Absolute Gauge 2 15.7 psi a 2.3 ft 1 3 0 PSI 4 1 psi g 16.7 psi a 4.6 ft 2 1 3 0 4 PSI 2 psi g 17.7 psi a 6.9 ft 2 1 3 0 PSI 4 3 psi g
Pressure Is all pressure positive?
Pressure (Suction Lift)? psi -10 0 10-20 PSI 20 23 ft Water Lever
Pressure (Suction Lift) -10 psi -10 0 10-20 PSI 20 23 ft Water Lever
Compound Gauge 0-10 10-20 PSI 20
Pressure (Suction Lift) Water Level 10 psi -10 psi 0-10 -20 PSI 10 20 0-10 -20 PSI 10 20 23 ft Total Pressure developed by pump 23 ft = 20 psi Water Level
Pressure (Water(?) Cooler) 1ft negative pressure 1ft
Hydraulic Energy Bernoulli Theorem
Hydraulic Energy
Hydraulic Energy Bernoulli Theorem Pressure (ft) Velocity (ft) Height (ft)
Pipe Pressure 50 psi 50 25 75 0 PSI 100 23 ft 60 psi 50 25 75 0 PSI 100
Pipe Pressure - Energy 50 50 25 75 25 75 50 psi + 23 ft 0 100 0 100 PSI PSI 50 psi + 23 ft 60 psi + 0 ft 23 ft 50 25 75 0 PSI 100 Constant Diameter
Pipe Velocity Energy Kinetic Energy = Velocity Head
Pipe Velocity Energy EGL 50 25 75 0 PSI 100 Pressure Energy Decreases Kinetic Energy Increase 50? 25 75 0 100 PSI Kinetic Energy Pressure Energy 50 25 75 0 PSI 100 HGL 50 psi 50 psi Flow 1 V 1 V 2 2 3 V 3
Pipe Pressure Eductor EGL Kinetic Energy Pressure Energy HGL 50 psi 50 psi 50 25 75 50 25 75 0 PSI 100 50 25? 75 0 100 PSI 0 PSI 100 Very Fast Flow 1 V 1 V 2 2 3 V 3 Negative Pressure = Vacuum
Bernoulli Theorem in air Fast Air Velocity LOWER Air Pressure Air travels over top and bottom The air over the top travels farther thus faster The lower air pressure on the top creates lift
Pipe Pressure - Energy Real World: Energy A = Energy B + Losses
Pipe Pressure - Energy 50 25 75 0 PSI 100 50 psi 50 psi 50 25 75 0 PSI 100 60 psi 23 ft 50 25 75 0 PSI 100 No Flow
Pipe Pressure - Energy 50 25 75 0 PSI 100 50 psi 50 46 psi 50 25 75 0 PSI 100 58 60 psi 23 ft 50 25 75 0 PSI 100 Some Flow
Pipe Pressure - Energy 50 25 75 0 PSI 100 50 psi 50 40 psi 50 25 75 0 PSI 100 60 psi 55 psi 23 ft 50 25 75 0 PSI 100 Lotsa Flow
Pipe Pressure - Energy Engineers spend a lot of time with HEADLOSS
Headloss Minor Losses Friction Losses
Minor Loss Water moving through: Valves Fittings Entrance/Exit Reducers
Major Loss?
Minor Loss Values of K: 0.2 = Gate Valve 0.5 = 90 Bend 1.5 = Tee 2.0 = Swing Check Valve 10.0 = Disk Check Valve 70.0 = Ball Check Valve!
Minor Loss if K = 23, V = 8 fps, then: = 23 ft pressure loss = 10 psi pressure loss
Friction Loss
Friction Loss Length & Headloss
Friction Loss Diameter & Headloss
Friction Loss
Friction Loss Diameter & Headloss?
Friction Loss Diameter & Headloss
Be Careful of True Diameter 12 Ductile Iron 12 HDPE O.D. = 13.1 I.D. = 12.2 O.D. = 13.2 I.D. = 10.8
Be careful of the diameter of your glass Although they restricted themselves to one drink at lunch time, Howard and Tom still found they were not at their most productive in the afternoons
Friction Loss + Minor Loss K
Friction Loss + Minor Loss Is this going somewhere? Yep..System Curve then Pump Curve
System Curve 2 System Extremes 1. Lift Station 2. Force Main
System Curve Lift Station High Static Lift Low Losses
System Curve Lift Station E Static Lift
System Curve Lift Station E Static Max Min Static Lift Lift Wet Well Level High Low
System Curve TDH (ft) Losses Min Static Lift Max Static Lift 1000 2000 Flow (gpm)
System Curve Force Main Little/no static lift High losses
System Curve Lift Station E
System Curve TDH Same Duty Point Flow (gpm)
Pump Curve TDH Flow (gpm)
Pump Curve Allowable Operating Range TDH Preferred Operating Range Flow (gpm)
Pump Efficiency BEP 80% 70% TDH 60% Flow (gpm)
Pump Curve BEP TDH Flow (gpm)
Pump Curve Add Valves And Pipe TDH Flow (gpm)
Pump Curve TDH Increase Diameter Flow (gpm)
Variable Frequency Drive (VFD) TDH 40 Hz 45 Hz 50 Hz 65 Hz 55 Hz Flow (gpm)
Variable Frequency Drive (VFD) BEP TDH 40 Hz 45 Hz 50 Hz 65 Hz 55 Hz Flow (gpm)
Variable Frequency Drive (VFD) BEP TDH 40 Hz 45 Hz 50 Hz 65 Hz 55 Hz Flow (gpm)
Title? 50 25 75 0 PSI 100 50 25 75 0 PSI 100
Title? 50 25 75 0 PSI 100 50 25 75 50 25 75 0 PSI 100 50 25 75 0 PSI 100 0 PSI 100
Joint Expo 2013 Open Channel Flow? Questions? Thank You Tim Sullivan IS GOING TO MESS SOMEBODY UP