Joint Expo 2012February 7-8, 2012

BASIC HYDRAULICS

Tim Sullivan, P.E.

Hubbell, Roth & Clark, Inc.

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Outline

• Pressure

• Hydraulic Energy and Head Losses

• System-Pump Curves

Concepts of hydraulics as they relate

to Operators and Mechanics

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Outline

Good News

Bad News

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Outline

Formulas

&

Math

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Outline

Good News?

No Test

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Outline

Formulas

&

Math

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pressure

Weight

of

Water

Depth

of

Water

Pressure = x

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pressure (ft)

2

1 3

40PSI

2

1 3

40PSI

2

1 3

40PSI

1 ft

2 ft

3 ft

1 ft

2 ft

3 ft

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pressure (in psi)

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pressure (psi per ft)

2

1 3

40PSI

2

1 3

40PSI

2

1 3

40PSI

2.3 ft

4.6 ft

6.9 ft

1 psi

2 psi

3 psi

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pressure (psi per ft)

2

1 3

40PSI

2

1 3

40PSI

2

1 3

40PSI

2.3 ft

4.6 ft

6.9 ft

51 psi

52 psi

53 psi

50 psi

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pressure (Gauge vs Absolute)

psig & psia

psia = psig + 14.7 psi

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pressure (Gauge vs Absolute)

2

1 3

40PSI

2

1 3

40PSI

2

1 3

40PSI

2.3 ft

4.6 ft

6.9 ft

14.7 psi

15.7 psia

16.7 psia

17.7 psia

Absolute Gauge

1 psig

2 psig

3 psig

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pressure

Is all pressure positive?

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

0

10

20PSI

-20

-10

Pressure (Suction Lift)

? psi

23 ft

Water Lever

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

0

10

20PSI

-20

-10

Pressure (Suction Lift)

-10 psi

23 ft

Water Lever

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Compound Gauge

0

10

20PSI

-20

-10

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pressure (Suction Lift)

23 ft

Water Level

0

10

20-20

-10

PSI

-10 psi

23 ft

10 psi0

10

20-20

-10

PSI

Water Level

Total Pressure

developed by pump

= 20 psi

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pressure (Water(?) Cooler)

1ft

1ft negative

pressure

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Hydraulic Energy

Bernoulli Theorem

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Hydraulic Energy

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Hydraulic Energy

Bernoulli Theorem

• Pressure (ft)

• Velocity (ft)

• Height (ft)

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pipe Pressure50

25 75

0PSI

100

23 ft

50

25 75

0PSI

100

50 psi

60 psi

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pipe Pressure - Energy50

25 75

0PSI

100

50

25 75

0PSI

100

50

25 75

0PSI

100

Constant Diameter

50 psi + 23 ft 50 psi + 23 ft

60 psi + 0 ft23 ft

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pipe Velocity Energy

Kinetic Energy = Velocity Head

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Flow

1

V1

V2 2

50

25 75

0PSI

100

3

V3

50

25 75

0PSI

100?

EGL

HGL

Kinetic

Energy

50

25 75

0PSI

100

Pressure

Energy

Kinetic

Energy

Increase

Pressure

Energy

Decreases

50 psi 50 psi

Pipe Velocity Energy

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pipe Pressure – Eductor

Very

Fast Flow 1V1 V2 2

50

25 75

0PSI

100

3

V3

50

25 75

0PSI

100?

EGL

HGL

50

25 75

0PSI

100

Kinetic

Energy

Negative Pressure = Vacuum

50 psi 50 psi

Pressure

Energy

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Bernoulli Theorem

“in air”

Air travels over top and bottom

The air over the top travels farther thus faster

The lower air pressure on the top creates lift

Fast Air Velocity

LOWER Air Pressure

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pipe Pressure - Energy

Real World:

EnergyA = EnergyB + Losses

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pipe Pressure - Energy50

25 75

0PSI

100

50

25 75

0PSI

100

50

25 75

0PSI

100

No Flow

23 ft

50 psi 50 psi

60 psi

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pipe Pressure - Energy50

25 75

0PSI

100

50

25 75

0PSI

100

50

25 75

0PSI

100

Some Flow

23 ft

50 psi 50 psi

60 psi58 psi

46 psi

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pipe Pressure - Energy50

25 75

0PSI

100

50

25 75

0PSI

100

50

25 75

0PSI

100

Lotsa Flow

23 ft

50 psi 50 psi

60 psi55 psi

40 psi

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pipe Pressure - Energy

Engineers spend a lot of

time with…

HEADLOSS

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Headloss

Minor Losses

Friction Losses

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Minor Loss

Water moving through:

• Valves

• Fittings

• Entrance/Exit

• Reducers

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Major Loss?

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

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 !

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Minor Loss

if K = 23, V = 8 fps, then:

= 23 ft pressure loss

= 10 psi pressure loss

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Friction Loss

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Length & Headloss

Friction Loss

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Diameter & Headloss

Friction Loss

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Friction Loss

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Friction Loss

Diameter & Headloss

?

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Friction Loss

Diameter & Headloss

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

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”

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

Be careful of the diameter of your glass

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Friction Loss + Minor LossK

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Friction Loss + Minor Loss

Is this going

somewhere?

Yep……..System Curve

………then Pump Curve

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

System Curve

2 System Extremes

1. Lift Station

2. Force Main

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

System Curve

Lift Station

• High Static Lift

• Low Losses

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

System Curve – Lift Station

Static

Lift

E

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Static

Lift

System Curve – Lift Station

E

Wet Well Level

High

Low

Min

Static

Lift

Max

Static

Lift

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

System Curve

TDH

(ft)

Flow (gpm)

Min

Static

Lift

1000

Losses

2000

Max

Static

Lift

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

System Curve

Force Main

• Little/no static lift

• High losses

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

System Curve – Lift Station

E

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

System Curve

TDH

Flow (gpm)

Same

Duty

Point

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pump Curve

TDH

Flow (gpm)

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pump Curve

TDH

Flow (gpm)

Allowable

Operating

Range

Preferred

Operating

Range

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pump Efficiency

TDH

Flow (gpm)

BEP

80%70%

60%

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pump Curve

TDH

Flow (gpm)

BEP

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pump Curve

TDH

Flow (gpm)

Add Valves

And Pipe

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Pump Curve

TDH

Flow (gpm)

Increase

Diameter

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Variable Frequency Drive (VFD)

TDH

Flow (gpm)

65 Hz

55 Hz

50 Hz45 Hz40 Hz

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Variable Frequency Drive (VFD)

TDH

Flow (gpm)

65 Hz

55 Hz

50 Hz45 Hz40 Hz

BEP

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Variable Frequency Drive (VFD)

TDH

Flow (gpm)

65 Hz

55 Hz

50 Hz45 Hz40 Hz

BEP

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Title?

50

25 75

0PSI

100

50

25 75

0PSI

100

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Title?

50

25 75

0PSI

100

50

25 75

0PSI

10050

25 75

0PSI

100

50

25 75

0PSI

100

Joint Expo 2012

BASIC HYDRAULICS

February 7-8, 2012

Joint Expo 2013

Open Channel Flow?

IS GOING TO MESS SOMEBODY UP

Questions?

Thank You

Tim Sullivan