Isman Slides Pump Day 2011

Course Outline

Water Supply Analysis Need for Fire Pumps Types of Pumps & Drivers Pump Placement & Sizing Piping & Appurtenances Inspection, Testing & Maintenance

Reference Standards

NFPA 20 - Fire Pumps

NFPA 22 - Water Storage Tanks NFPA 24 - Fire Service Mains NFPA 25 - Inspection, Testing and

Maintenance of Water Based Fire Protection Systems

Basic Hydraulics Flow

– Volume of water moving through a system (or past a point) in a given period of time

– measured in gpm or L/min Pressure

– The energy available to do work (move water)

– Measured in psi or bar

Basic Hydraulics

Head– Another way of expressing energy based on

the equivalent height of a fluid column– measured in feet or meters

Pressure/HeadRelationship for Water

P = .433H

P = Pressure in psi

H = Height of elevation of water in feet

Tank

WaterLevel

150 ft

Laminar Flow

Turbulent Flow

Laminar & Turbulent Flow

Water Supply Analysis

Perform flow tests Adjust for realistic worst case

– Time of day– Time of year

Take into account future growth

FLOW

Sprinkler System Underground

Pressure or Test Hydrant

Pressure Gauge

Flow Hydrant

WATER MAIN

EXAMPLE Static Pressure ..................... 80 psi Residual Pressure ................ 47 psi Pitot Reading ....................... 14 Hydrant Coefficient .............. .90 Butt Opening ........................ 2.5 inches Flow = ?

Flow Formula

Flow (in gpm) = Q = 29.83 x (D)2 x CH x (PT)1/2

Q = 29.83 x (2.5)2 x 0.9 x (14)1/2

Q = 29.83 x 6.25 x 0.9 x 3.74

Q = 627 gpm

100 200 300 400 500 600 700 800

PRESSURE

100 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0

FLOW - GPM

FLOW TEST SUMMARY SHEET

PRESSURE

100 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0

100 200 300 400 500 600 700 800

FLOW - GPM



PRESSURE

100 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0

100 200 300 400 500 600 700 800

FLOW - GPM

Water Supply

Determining Pressure at Any Given Flow

Use graph of water supply data Use Formula: P = (PR - PS)(Q/QR)1.85 + PS

P = Pressure at any given flow

Q = Flow at which you want to know P

PR = Residual pressure measured in test

PS = Static pressure measured in test

QR = Residual flow measured in test

Adjustments Need to account for differences in elevation

between water supply and fire protection system (For this Example, assume none)

Need to evaluate water supply at reasonable worst case for daily and seasonal use

For this example– 24 hour gauge showed variation in static pressure from

72 to 84 psi– Seasonal knowledge of water supply says static

pressures vary from 65 to 85 psi


PRESSURE

100 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0

100 200 300 400 500 600 700 800

FLOW - GPM

Water SupplyWater Supply - Adjusted for seasonal and daily use

Why Do We Need Pumps ?

When the water supply can provide sufficient flow, but does not have the pressure to meet the demand of the fire protection system, pump can be used

Pumps will not increase flow


PRESSURE

100 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0

100 200 300 400 500 600 700 800

FLOW - GPM

Water Supply


PRESSURE

100 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0

100 200 300 400 500 600 700 800

FLOW - GPM

Water Supply

Water Supply With Pump

Pump Pressures Discharge Pressure

– Gage pressure measured on the discharge flange of the pump

Suction Pressure– Gage pressure measured on the suction

flange of the pump– Energy of the water delivered to the pump– Function of water supply, not pump– Must be positive

Pump Pressures

Net Pressure– Pressure produced by the pump– Difference between Discharge Pressure and

Suction Pressure

PN = PD - PS

PD = PS + PN

Types of Pumps

Centrifugal Pumps - use centrifugal force to increase water’s energy (pressure)

Positive Displacement Pumps - push water with pistons or rotary gears to increase water’s energy (pressure)

Centrifugal Force An object dropped in the center of a

rotating disk will pick up energy from the rotation

The object will move towards the outside of the disk

If unrestrained, the object will be thrown off when the object reaches the edge (kinetic energy)

If restrained, the object will store the energy as potential energy (pressure)

Centrifugal Pump Components Impeller

– Vanes– Shrouds– Eye

Impeller Shaft Packing Casing

Impeller Shaft

Horizontal - attached to horizontal driver

Vertical - attached to vertical driver Vertical - attached to horizontal driver

through right angle gear drive

Packing

Seal between the inside of the pump and the outside of the pump where the shaft penetrates the casing

Must be kept moist Gland around packing designed to leak

Pump Design

Single Suction - Water only enters the eye on one side of the impeller

Double Suction - Water enters the impeller from both sides

Single Suction Double Suction

Multi-Stage Centrifugal Pumps

More than one impeller inside the casing

Parallel - water goes to all impellers simultaneously

Series - all of the water goes to one impeller first, then from that impeller into the next

Two-StagePump inParallel

Two-StagePump inSeries

Types of Centrifugal Pumps Horizontal Pump Vertical Pump End Suction Pump Horizontal Split Case Pump In-Line Pump Vertical (Line) Shaft Turbine Pump Can Pump

End Suction Pump

Horizontal Split Case Pump

Vertical In-Line Pump

Vertical Shaft Turbine Pump

Pump Drivers

Electric Motors Diesel Engines Steam Turbines Gasoline Engines - no longer allowed

Electric Motors

Power source must be reliable– Public Utility – Separate Service– Private Power Station

Noncombustible Construction

Secondary Power SourceRequired When:

1. Reliable power source cannot be obtained from a public utility or a private station.

2. The pump is protecting a high-rise building and the needs of the fire protection system cannot be supplied by FD pumper.

3. Another code or ordinance requires

Generators

Type 10, Level 1, Class X (8 hrs at 100% of rated capacity)

Handle All Loads– Load Shedding Allowed

Diesel Engines

Batteries Exhaust Ventilation Coolant Noise

Pump Drivers - Power Horsepower Brake Horsepower Gross Brake Horsepower Net Brake Horsepower Water Horsepower

WHPnet = Q x P

1714 x E

Pump Sizing and Placement

Pump Sizing

Rated Flow (25-5000 gpm) Rated Pressure (40-200 net psi) Rated Speed

Permissible Performance Ranges

Allows maximum 140% rated net pressure at churn (no flow)

Requires a minimum of 65% rated net pressure at 150% of rated flow (max. flow)

Pump Sizing

Calculate system demand to pump discharge flange

Calculate water supply to pump suction flange Select pump so that the system flow demand is

less than 150% of the rated flow of the pump (less than 140% recommended)

Pump Sizing Using the Manufacturers Pump Curve, find the

pump’s net pressure at the system demand flow Add the suction pressure (at demand flow) to

the net pressure (at demand flow) to get the discharge pressure (at demand flow)

If the discharge pressure is greater than the demand, okay. If not, select new pump.

Fire Pump Sizing

Advantages of Specific Model Sizing– Know exactly how the pump will perform– Match pump’s performance to system demands– Capable of predicting maximum pressure

Disadvantages to Specific Model Sizing– Not always possible to know system demand– Not always possible to know which model pump will be

used in the conceptual stages of design

Alternative Method for Specifying Fire Pump Size

Estimate fire protection system demand at pump discharge flange

Assume a pump with a specific rated flow and pressure– Assume that the pressure will not increase at flows

less than the rated flow– Assume that the pump will perform to the minimum

point of 65% of rated pressure at 150% of rated flow Perform Specific Model Analysis Later

Alternative Method for Specifying Fire Pump Size

0 20 40 60 80 100 120 150Flow (% of Rated Flow)

140

20

50

80

110

Pre

ssur

e (%

of

Rat

ed P

ress

ure)

Minimum Pressures Produced by Pump

Maximum Pressure Produced by Pump

Pump House/Pump RoomNFPA 20 requires protection from: Explosion and fire Flood and earthquake Rodents and insects Windstorm and freezing Vandalism Other adverse conditions

Pump House/Pump Room

Pump House– Construction– Separation

Pump Room– Separation– Accessibility

Pump House / Pump Room Size - fit pump, equipment, and suction

pipe Heat - at least 40° F (more for diesel) Ventilation Light - artificial and emergency Drainage - size and pitch

Suction Pipe

Straight run to suction flange Vertical bend into suction flange Horizontal bend into suction flange

Suction Pipe Size The size of the suction pipe . . . shall be such

that . . . At 150% of rated capacity, the gage pressure at the pump suction flange shall be 0 psig or higher. (Note: Pressure is allowed to go as low as -3 psig for tanks on same level as pump)

The size of that portion of the suction pipe located within 10 pipe diameters upstream of the pump suction flange shall be not less than that specified in Table 5-25(a) or (b).

Suction Pressure

Must be positive Evaluate at maximum flow of pump

(150% of rated flow) Take into account friction loss of all pipe

and components between water supply and pump

Take into account elevation between water supply and pump

Suction Pressure Calculation

Find the residual pressure of the water supply at the maximum flow for the pump (150% of rated flow). Call this PR.

Calculate all pressure losses (friction and elevation) between the water supply and the pump suction flange at maximum flow for the pump. Call this PL.

The Suction Pressure will be the residual pressure from the water supply minus the pressure losses.

PS = PR - PL

Suction Pressure CalculationExample

1500 gpm pump



Analysis at 2250 gpm (150% of 1500) Residual Pressure = 24 psi (from graph) Friction loss through underground = 2.4 psi Friction loss in pump room piping = 1.2 psi Friction loss through backflow = 8.0 psi Elevation loss = 0.0 psi PS = 24 - 2.4 - 1.2 - 8.0 - 0.0 = 12.4 psi

Design / Installation of Suction Pipe

NFPA 24 Air Pockets Air Leaks Eccentric Reducers Protection from Freezing Hydrostatic Testing Screens (Open Water Source)

Reducers

Devices in Suction Pipe Control Valves Check Valves Vortex Plates Low Pressure Cut-off Devices Low Pressure Throttling Devices By-Pass Piping Backflow Preventers

Discharge Piping

Steel - Rated for Maximum Working Pressure

Maximum Working Pressure = Static Pressure + (Net) Churn Pressure

Devices in Discharge Piping Control Valve Check Valve Pressure Relief Valve - only required if

discharge pressure exceeds components’ ratings (evaluate at component)

Circulating Relief Valve– Required for electric driven pumps– Required for diesel driven pumps with radiator

cooling

Discharge Pipe and Components

Fire Pump PressureRelief Valves

Pressure ReliefValve

Fire Pump CirculationRelief Valves

Circulationrelief valve

Testing Arrangements

Test Header to Open Flow to Reservoir Closed Loop Metering

Test Headers Listed Outlets (Table 2-20) Location Shut-off Valve (if needed) Drain Pipe Size (Table 2-20)

Determining Flow Pitot Gage

Flow Meter– Listed– 175% of Rated Flow– Size (Table 2-20)

Pitot Gage

Converting Pitot to FlowQ=29.83 c d2 P

Q = flow in gpm

c = 0.97

d = nozzle diameter in inches

P = Pitot pressure in psi

Sensing Lines Connected between discharge check

valve and control valve Separate for each pump Minimum 1/2” corrosion resistant pipe Check valves/Ground Face Unions

Pressure Sensing Line Connections

Valve SupervisionControl Valves

Suction, Discharge, By-Pass, Test Outlet

1. Central station, proprietary, or remote signaling service.

2. Local signaling service providing an audible signal at constantly attended location.

3. Locking valves open.

4. Sealing of valves in a fenced enclosure

NFPA 25

Inspection, Testing and Maintenance of Water Based Fire Protection

Systems

Weekly Inspection of

Pump Components

Pump House

Adequate Heat

Ventilating Louvers Operational

Hydraulic Systems

Suction & Discharge Valves Open

Suction Pressure Gage Normal

System Pressure Gage Normal

Reservoir Full

Electrical SystemsController Power “on”

Transfer Switch “normal”

Isolating Switch Closed

Reverse Phase Light off

or

Normal Phase Light on

Diesel EnginesFuel Tank 2/3 Full

Controller in “Auto” position

Battery Voltage Normal

Charger Readings Normal

Battery Pilot Lights on

or

Failure Lights off

Alarm Lights off

Engine Run Time Meter Reading

Oil Level Normal

Crank Case Oil Level Normal

Cooling Water Level Normal

Electrolyte level (batteries) Normal

No Corrosion on Battery Terminals

Water-jacket Heater Operating

Weekly Tests (No Flow)

Automatic Start

Electric Pumps - 10 minutes

Diesel Drivers - 30 minutes

Record During TestSuction & Discharge Pressures

Slight Discharge from Packing Gland

No Unusual Noise or Vibrations

No Overheating

Pump Starting Pressure

Time to Achieve Full Speed

Time Controller on First Step

Suction Pressure Discharge Pressure

Time Pump Runs After Starting

(for Auto-Stop Controllers)

Time for Engine to Crank

Time to Reach Run Speed

Engine Oil Pressure, Speed, Water and Oil Temperature

Water Flow in Heat Exchanger

Annual Flow Test

No Flow

Rated Flow

Peak Flow

Test OptionsTest Header to Hose Streams

Flow Meter to Drain or Suction Reservoir

Closed Loop Metering

At Churn

Check Circulation Relief Valve

Check Pressure Relief Valve

Run Test for 30 minutes

At Flow ConditionsRecord Voltage & Current

Record Pump RPM

Record Suction & Discharge Pressures

Record Flow

Observe Alarm Operations

Testing Equipment

Pressure Gages

Tachometer

Ammeter

Hose & Playpipes

Pitot Tube

Flow Meter

Converting Flow to Pitot

Q = flow in gpm

c = 0.97

d = nozzle diameter in inches

P = Pitot pressure in psi

2

283.29

cd

QP

Test Procedure - for Test Header and Hoses

1. Water at test header (all air out of system)

2. Start the pump

3. General pump operation

No unusual vibrations, noises, oil or water leaks

4. Check packing gland

5. At churn (no flow into system), record:

Suction Pressure, Discharge Pressure, RPM

Amperes & Volts (if applicable)

6. Open test header valves

Achieve 100% of rated flow

7. At rated flow, record:

Suction Pressure, Discharge Pressure

RPM, Pitot Gage Readings (if applicable), Amperes & Volts (if applicable)

Test Procedure - for Test Header and Hoses (continued)

8. Open test header valves to achieve 150% of rated flow

9. Record data at 150% of rated flow


10. Calculate pump net pressures

11. Plot flow curve

12. Compare flow curve to manufacturers shop curve

13. Plot ampere curve (electric motor)

14. Compare ampere curve to manufacturers curve


Test Procedure - for Flow Meters

1. Prime pump (get all air out)

2. Discharge valve closed

3. Start the pump

4. General pump operation

No unusual vibrations, noises, oil or water leaks

5. Check packing gland

6. At churn (no flow in system), record:


Amperes & Volts (if applicable)

7. Open (flow meter) to achieve 100% of rated flow

8. At rated flow, record:


Pitot Gage Readings (if applicable), Amperes & Volts (if applicable)


9. Open the flow meter valve to achieve 150% of rated flow

10. Record data at 150% of rated flow

11. Calculate pump net pressures

12. Plot flow curve

13. Compare flow curve to manufacturers

14. Plot ampere curve

15. Compare ampere curve to manufacturers


Activate Suction Throttling Valve

Simulate Power Failureif Transfer Switch Installed

Alarm Sensors&

Indicating Devices

Pump Test Data

Test

100%

Churn

150%

Driver Suction Pressure Net Nozzle Flows TotalSpeed Discharge Size Pito/Flow Flow

RPM psi psi psi Inches 1 2 3 4 gpm

Q = 29.83 X D X C X P2 VC = .97

1700 16 125 N/A 0 0 0 0 0

60 601690 16 110 1 3/4

35 37 48 481675 16 85 1 3/4

Pump Test Data

Test

100%

Churn

150%

Driver Suction Pressure Net Nozzle Flows TotalSpeed Discharge Size Pito/Flow Flow

RPM psi psi psi Inches 1 2 3 4 gpm

Q = 29.83 X D X C X P2 VC = .97

1700 16 125 109 N/A 0 0 0 0 0

60 601690 16 110 94 1 3/4 686 686 1372

35 37 48 481675 16 85 69 1 3/4 524 539 614 614 2291

Adjustment Formulas

Q’ = Q(Rated Speed/Test Speed)

PN’ = PN(Rated Speed/Test Speed)2

Q’ = 0(1760/1700) = 0 gpm

P’=109(1760/1700)2 = 117 psi

Q’ = 1372(1760/1690) = 1429 gpm

P’ = 94(1760/1690)2 = 102 psi

Q’ = 2291(1760/1675) = 2407 gpm

P’ = 69(1760/1675)2 = 76 psi

Thank You!

Documents

Isman Slides Pump Day 2011