Information_on_Fire_Flow_Testing_of_Hydrants.pdf

8/11/2019 Information_on_Fire_Flow_Testing_of_Hydrants.pdf

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H Y D R O F L O W P R O D U C T S , I N C .

APPLICATIONSFire Flow Testing

GeneralFire ow tests are conducted on hydrants to determinewater availability in planning for reghting activities,re sprinkler systems or domestic water demand. The testsare also useful in determining the general condition ofthe water distribution system by detecting closed valvesor wall deposits. A well-maintained water system enablesreghters to extinguish ames and prevent large-scaledamage or loss of life. There are two types of re ow tests.

Main Capacity Test determines the water supplyavailable in the water main. If you are designinga re sprinkler system, use this test (residual hydrant+ separate downstream ow hydrant).

Hydrant Capacity Test determines the ow-rateavailable from the hydrant and if it will deliver in a reemergency situation. If you are performing re ow

tests of hydrants, use this test (residual hydrant andow hydrant are the same one).Both tests are valid and discover valuable engineeringinformation as well as test the integrity of the piping systemcomponents. It is important to perform the correct test.

Where do I nd more informationon re ow testing?

NFPA 291 Recommended practice for re owtesting and marking of hydrantsAWWA M17 Installation, eld testing andmaintenance of re hydrants

What equipment do I need for Fire Flow Testing? Hose Monster1) Little Hose Monster (HML) 1500 GPM or less.Small, lightweight and pitotless (no pitot damage fromushing debris).2 1 2 Hose Monster (HM2H) 1500 GPM or less.Steel body, built-in-pitot.4 or 4 1 2 Hose Monster (HM4, HM4H) 10002800 GPM. Steel body. Flow from the pumperport. Ideal for large capacity systems owing more tha1400 GPM. 2 Pitotless Nozzle2) (PN2GRV, PN2THD) For use with the Little Hose Monster (use PN2GRV) othe 2 Hose Monster (use PN2THD). It measures froabout 3501500 GPM and is the most common sizefor hydrant re ow testing. Smaller sizes can be usedfor lower ow-rates.Discharge Flow-rate Gauge (GK100D4,3)GK60D4) 60- and 100-psi gauges are common.Anticipate pressure ranges within your distributionsystem so readings are in the middle third of the dial.Remote Reader (HMRR124) ) Enables you totake gauge readings at a convenient distance fromdischarge. Sold in three lengths, the 12 length isusually sufcient for re ow testing.


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APPLICATIFire Flow Testing (Continued)

Test Hose (H2H.5, H2H.10RR, H4.5, H45.5) 5)Length: For re ow testing, 5 or 10 lengths aremost common.Options for attaching a hose to a hydrant:

Attach a 2-diameter hose to the pumper portoby using a reducer. This is our preferred optionbecause it enables a Little Hose Monster or 2Hose Monster to be used from the pumper port andusually positions discharge directly in street gutter.Attach a 2-diameter hose to the nozzle port of theohydrant. The hydrant nozzle ports are usually locatedon the sides of the hydrant and parallel to the street.A 10 hose with a slight arc out of the nozzle portshould discharge water in a street gutter.Attach a 4 or 4 hose to the pumper port of theohydrant. The pumper port of a hydrant is usuallypositioned so a 5 hose out of the pumper port shouldposition discharge directly in street gutter. This isusually used with a 4 or 4 Hose Monster, but canbe used with the HML and HM2H if a reduceris attached to the end of the hose.

Hydrant Gate Valve (HGV25, HGV4, HGV45)6) This enables greater control of the water ow andreduces stress and opportunities for water hammerwhen opening or closing hydrants.Gauge Cap (GCSW) 7) This component collectsstatic and residual pressure readings from a hydrantin a re ow test. It attaches to the 2 NST nozzleport on the residual hydrant.

Static/Residual Pressure Gauges (GK160D4,8)GK100D4) 100- or 160-psi gauges are mostcommon. Anticipate pressure ranges within yourdistribution system so readings are in the middle thirdof the dial.Hydrant Wrench (HW107) 9) Enables youto unscrew caps and open a hydrant to ow water.Spanner Wrench (WSPA101, WSPA104) 10)Spanner Wrench (WSPA101) attaches a hoseto a hydrant or Pitotless NozzlePitotless Nozzle Wrench (WSPA 104) attachesa Pitotless Nozzle to a 2 Hose Monster (HM2Hor HM2HF)

Also consider:Dechlor Demon11) (DD2H, DD4, DD4H) Designed for dechlorinating discharge water whileow testing without affecting ow-rate measurements.Contact your local authority having jurisdiction for moreinformation when dealing with super-chlorinated watermains or discharging near lakes or rivers.Reducer Adapter (AD4.25, AD45.2512) ) Enablesa 2 hose to be owed from the pumper port of ahydrant so that a Little Hose Monster or a 2 HoseMonster can be used.

Gauge Case (CASE520, CASE720, CASE920) 13)Foam-padded cases keep gauges and Pitotless Nozzlesprotected and prevent damage.Software (IMS, FFT) 14)Infrastructure Management Systems collectscritical data and provides detailed reports to manage

your water distribution systems. IMS does all thecalculations for you and provides reports and graphsthat are unmatched for accuracy and details. It willautomatically grade your re hydrant capabilities perthe NFPA recommendations.Fire Flow Tester Software helps you performre ow tests to determine water availability for resprinkler systems, re ghting, city planning and toachieve favorable ISO ratings. FFT produces usefulreports that calculate predicted ow-rates and givesother useful information like the NFPA class and colorcode for each hydrant tested.Gauge Calibration (GCC2H, GCC4) 15)For re ow testing, NFPA recommends test gaugesbe calibrated within 12 months prior to the test.We offer gauge calibration for new and used gaugesthat ensures accuracy. It comes with a NIST certicateStream Shaper (SS1) 16) For high-pressure ow-rates, used to prevent hose burn.45 or 30 Test Header Elbow (EL452HNH,17)EL302HNH) Enables the hose to be angleddifferently and positions the discharge water

in a different area.Terminology Flow Hydrant The hydrant that ows water and measures thetest ow-rate.Hydrant Capacity Test A type of re ow test that evaluates thewater supply available from the hydrant.Main Capacity Test A type of re ow test that evaluates thewater supply of the re main at the location of the residual hydrant. Nozzle Pressure The pressure measured at a nozzle in a reow or re pump test. It can describe the Pitotless Nozzle, hydrantnozzle or the orice on the Hose Monster. Nozzle pressure, pitotpressure and velocity pressure are often used interchangeably.Rated Capacity The water supply available at a specied

residual pressure (usually 20 psi). Residual Hydrant Also known as Test Hydrant . In a re owtest, this hydrant measures static and residual pressures. Test resultsapply to this hydrant.Residual Pressure The pressure residing in the waterdistribution system when owing in a re ow test or any otheractual owing condition.Static Pressure Water distribution system pressure at zerotest ow.Test Flow-rate The ow-rate of water that is dischargedin a re ow or re pump test. Test Hydrant Also known asResidual Hydrant . In a re ow test,this hydrant measures static and residual pressures. Test results applyto this hydrant.


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APPLICATIONSFire Flow Testing (Continued)

TheHydrant Capacity Test evaluates the water supply availablefrom the hydrant. The informationderived from this test is used by there service to plan for ghting res.If all hydrants in a system are tested,partially closed valves and otherobstructions will become known.This test uses a single hydrant as boththe test hydrant and the ow hydrant.

Setup At the test hydrant (pressurehydrant, static/residual hydrant):1. Attach gauge cap.2. Attach hydrant slow-close gate

valve and tighten all other caps.3. Set the Little Hose Monster

with Pitotless Nozzle in anappropriate location for owingwater.

4. Attach hose to Pitotless Nozzleand Little Hose Monster assembly.

5. Attach Remote Reader assemblyand gauge to Pitotless Nozzle.

Conduct the test1. Slowly open the hydrant using

the gauge cap to purge air fromthe hydrant. Close it when airis vented.

2. Record static pressure fromgauge cap.

3. Slowly open hydrant gate valveto desired ow-rate (usually fullopen).

4. When the ow-rate stabilizes,a. Record nozzle pressure from

the remote reader.and at the same moment

b. Record the residual pressurereading from the gauge cap.

At this point, the test iscomplete.

5. Slowly close gate valve, thenclose the hydrant. Remove testequipment from hydrant. Replaceand tighten cap. If the hydrant isa dry barrel type, note that waterdrains properly from the hydrant.Remove Remote Reader andgauge from the Pitotless Nozzle.

6. Record the number of minutes thatwater was owing. This can beused to account for the amountof water used during the ow test.

The information collected from this tecan be used to predict ow-rates andresidual pressures. IMS and Fire FlowTester are software packages formanaging water distribution systemsand conducting re ow tests.

Hydrant Capacity Flow TestSingle-hydrant ow test

Test Hydrantand

Flow Hydrant

Nozzle Pressure

Static/Residual Gauge

F i r e M a i n

Evaluates water

available at thispoint in the system


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APPLICATIFire Flow Testing (Continued)

A Main Capacity Test evaluatesthe water supply of the re main atthe location of the test hydrant. Theinformation derived from this test isused by city planners and contractorsto consider the water supply forgeneral use and re sprinkler systems.

Setup At the test hydrant (pressurehydrant, static/residual hydrant):1. Attach gauge cap to test hydrant.

Tighten all other caps.2. Open test hydrant, vent air from

hydrant body through the valveon the gauge cap assembly.Close it when air is vented.

At the ow hydrant1. Set the Little Hose Monster with

gauge to the Pitotless Nozzle in an appropriate location forowing water.

2. Attach Remote Reader and gaugeto the Pitotless Nozzle.

3. Attach hydrant gate valve to thehydrant and close the gate valve.

4. Tighten other caps.5. Attach the hose to the Pitotless

Nozzle and Little Hose Monsterassembly.

Conduct the test1. Record static pressure reading

from gauge cap.2. Slowly open hydrant using the

gate valve to purge air from thehydrant. When hydrant is full ofwater, open gate valve to desiredow-rate (usually full open).

3. When the ow-rate stabilizes,a. Record nozzle pressure from

the remote reader.and at the same moment

At the test hydrantb. Record the residual pressure

reading from the gauge cap.

At this point, the test is

complete.4. Slowly close gate valve onow hydrant, then close thehydrant. Remove test equipmentfrom hydrant. Replace andtighten cap. If the hydrant isa dry barrel type, note thatwater drains properly from thehydrant.

5. Record the number of minutesthat water was owing. Thiscan be used to account for theamount of water used duringthe ow test.

At the test hydrant6. Close the hydrant. Remove

gauge cap and replacehydrant cap. If the hydrant isa dry barrel type, note thatwater drains properly from thehydrant.

The information collected from this tecan be used to predict ow-rates andresidual pressures. IMS and Fire FlowTester are software packages formanaging water distribution systemsand conducting re ow tests.

Main Capacity Flow TestTwo-hydrant ow test

Flow Hydrant

Residual Hydrant

Static/ResidualGauge

Nozzle Pressure

F i r e

M a i n

Evaluates wateravailable at thispoint in the system.


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APPLICATIONSFire Flow Testing (Continued)

How much is the friction loss when I usea hose?

There is friction loss when owing through a hose, but ina re ow test, it doesnt matter. The purpose of a re owtest is to evaluate the water supply, or the ow-rate thatwill be available when the system is brought down to20 psi residual.

A re ow test requires three measurements: static pressure,residual pressure and test ow-rate. The reading from thegauge cap on the residual hydrant gives you static pressureand residual pressure. The Pitotless Nozzle or HoseMonster gives you the test ow-rate.

The friction loss created in the hose results in a lower test

ow-rateand a greater residual pressure. This will not affectthe predicted ow at 20 psi as long as there is a sufcientdrop in static-to-residual pressure. NFPA 291, 4.3.6, 2010recommends a drop of at least 25% from static to residualpressure. AWWA M17 recommends a drop of at least 10PSI from static to residual pressure.

To illustrate that friction loss does not have an effect on thepredicted ow-rate:

Test #11) measures the test owthrough an openhydrant nozzle with a hand-held pitot .

Static 85 psiResidual 60 psi

Pitot 36 psiTest ow 1007 GPM

Predicted ow at 20 psi = 1687 GPM

Test #22) measures the test owthrough 2 x 10 hose and the 2 Hose Monster .

Static 85 psiResidual 70 psiPitot 20 psiTest ow 764 GPM

Predicted ow at 20 psi = 1687 GPM

Flow test equipment does not affect staticpressure.

because of the friction loss in 10 of hose.

causes a backpressure which increasesresidual pressure. The higher residualpressure compensates for the lower testow-rate.

equal. Test points from both tests fall on the same line othe graph.

In summary, thetest ows will be different, but thedifference will not affect theow test . The Hose Monsterand hose will result in a lower test ow-rate and a higherresidual pressure. When all data is considered, the owtests result in the same predicted ow-rates.

Test #1

Test #2

90

80706050403020100

7060

20

764Flow-rate GPM

1007 1687

Pressure

PSI

Test #2 Test #1

Predicted flow the same

Flow Graph

Information_on_Fire_Flow_Testing_of_Hydrants.pdf

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