Analysis of residential single jet meter accuracy ......**FACSA. Calle Mayor 82. 12001 Castellon....

Analysis of residential single jet meter accuracy degradation rate

F.J. Arregui*, F.J. Gavara

* Universitat Politecnica Valencia. Camino de Vera s/n. 46022

Valencia. Spain – [email protected]

**FACSA. Calle Mayor 82. 12001 Castellon. Spain -

[email protected]

This presentation was made by Francisco Arregui at the IWA

International Conference on Water Efficiency and Performance

Assessment of Water Services Conference in Cincinnati U.S.A in April

2015.

The authors have confirmed that they are entitled to grant this

permission for copies to be made available free of charge for reading

and/or downloading from the LEAKSSuite website.

Water Efficiency and Performance Assessment of Water Services - Cincinnati, Ohio (USA) - April 20-24, 2015

Francisco Arregui – [email protected]

Francesc Gavara – [email protected]

The company in figures

• Serves more than 1.5 million customers

• 200 towns, mostly medium and small size

• Distributes 300 MLD

• 3000 km of pipes

• 375,380 customer meters

Water Efficiency and Performance Assessment of Water Services - Cincinnati, Ohio - April 2015

Metering errors vary with flow rate

-10

-5

0

5

10 100 1000 10000

Flow rate (l/h)

Err

or

(%)

Class B Velocity meter 30 l/h 120 l/h 3000 l/h

Leaks

New meter

Starting flow


Metering errors vary with flow rate

-10

-5

0

5

10 100 1000 10000

Flow rate (l/h)

Err

or

(%)

Class C - PD 15 l/h 22.5 l/h 3000 l/h

New meter

Starting flow


What happens to meters when they get old?

-10

-5

0

5

10 100 1000 10000

Flow rate (l/h)

Err

or

(%)

Class B Velocity meter 30 l/h 120 l/h 3000 l/h

Leaks

New meter Old meter


Finding real field performance of a meter

Weighted error

Water consumption pattern Error curve

-10

-5

0

5

10

1 10 100 1000

Erro

r (%

)

Flow rate (l/h)

0

10

20

30

40

50

4,71,9 1,3 0,8 0,5 0,4 1,1 1,1

6,3

25,3

43,3

11,9

1,2 0,2

Wate

r co

nsu

mp

tio

n (

%)

Flow rate (l/h)


Understanding weighted error of a meter

Weighted error of -X%

-10

-5

0

5

10

1 10 100 1000

Erro

r (%

)

Flow rate (l/h)

0

10

20

30

40

50

4,71,9 1,3 0,8 0,5 0,4 1,1 1,1

6,3

25,3

43,3

11,9

1,2 0,2

Wate

r co

nsu

mp

tio

n (

%)

Flow rate (l/h)

-X% weighted error means that every 100 litres consumed X litres are not measured

It is strictly associated to: One meter (or type of meter)

One customer (or type of customer)


Consumption pattern

Results were taken from a previous research in the same city in 2006

200 domestic customers were monitored

This consumption pattern is currently being updated

Flow rates (l/h) Consumption (%)

0-6 3.2

6-12 1.8

12-24 2.3

24-45 2.4

45-90 3.7

90-250 8.6

250-1000 72.7

1000-2000 4.5

2000-3000 0.8

>3000 0


Findings about the weighted error of new domestic meters

The following results are associated to the specific consumption pattern of the city

Class B or Equivalent Class C or Equivalent

Positive

displacement


Findings the error curve of used water meters

A sample of: Model 1: 819 meters

Model 2: 409 meters

Meters were tested at 7 flow rates

The sample tried to cover different ages and accumulated volumes Model 1: From 3 to 10 years of age

Model 2: From 1 to 7 years of age


Weighted error vs age

Model 1


Weighted error vs accumulated volume

Model 1


Weighted error vs age-accumulated volume

Model 1


Combined degradation model

𝜀𝑤𝑒𝑖𝑔ℎ𝑡𝑒𝑑 = 𝐴 · ln 𝐴𝑔𝑒 + 1 + 𝐵 + (𝐶 · 𝑉𝑜𝑙2 + 𝐷 · 𝑉𝑜𝑙

Degradation accounting for

age


accumulated volume

-0.69 -5.29 -5.75E-7 -4.1E-4


Weighted error vs age

Model 2


Weighted error vs accumulated volume

Model 2


Weighted error vs age-accumulated volume

Model 2


Comparison: Age

Model 2

Model 1


Comparison: Acc. volume

Model 2

Model 1


Conclusions

Linear degradation with age may not be valid

Extremely different degradation rates for two models

A combined model accounting for age and accumulated volume is needed (different from each model)

𝜀𝑤𝑒𝑖𝑔ℎ𝑡𝑒𝑑 = 𝐴 · ln 𝐴𝑔𝑒 + 1 + 𝐵 + (𝐶 · 𝑉𝑜𝑙2 + 𝐷 · 𝑉𝑜𝑙


age


accumulated volume

Analysis of residential single jet meter accuracy ......**FACSA. Calle Mayor 82. 12001 Castellon....

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