Time Domain Reflectometry:Time Domain Reflectometry:Co-operation between a University and a Water Co-operation between a University and a Water Operator in developing an innovative system for Operator in developing an innovative system for

identifying and monitoring pipe leaks (S.I.M.P.Le)identifying and monitoring pipe leaks (S.I.M.P.Le)

Bari, 29/01/2013

A. Cataldo (speaker), E. De Benedetto, G. CannazzaDepartment of Engineering for Innovation

Università del SalentoLecce, Italy

M. Miraglia, D. AncoraAcquedotto Pugliese S.p.A

Bari, Italy

March 13, 2013 Thistle Marble Arch, London

N. GiaquintoDepartment of Electrics and Electronics

Politecnico di BariBari, Italy

Goals of the collaborative project

Develop, test and realize an innovative system, based on time domain reflectometry (TDR), for the localization of leaks in underground water and sewer pipes

Carrying out of the project:Nov. 2011 – Nov. 2012

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

S.I.M.P.Le.S.I.M.P.Le.System for Identyfing and Monitoring System for Identyfing and Monitoring

of Pipe LEaksof Pipe LEaks

Outline

28,000 students

750 academic staff

635 technical and administrative staff

3 Campuses

10 Faculties

17 Departments

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

Partners involved (1/2)

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

OutlinePartners involved (2/2)

the largest European Water operator, as per extension of its networks

water distribution networks extends for over 22,000 km

> 4 million people served

approximately 18,000 liters/second of water delivered

The physical principles behind the system

(time domain reflectometry -TDR)

Conclusions and further developments

Use and advantages of SIMPLe in two application scenarios, i.e. leak detection in

- already-installed metal pipes

- newly-installed pipes, made of any material

Results of the on-the-field experimental validation

Outline

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

S.I.M.P.Le.S.I.M.P.Le.

State-of-the-art of leak-detection methods

,

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

Traditional methods Acoustic logging, Listening rods, Noise correlator, geophone

Propagation of mechanical waves

Other methods GPR, tracer gas technique, thermography, etc.

various

drawbacks

• Time-consuming• Leak-localization accuracy affected by

operative conditions (i.e.: water water pressure, pipe material, environmental pressure, pipe material, environmental noisenoise, etc.)

• High costs• Experienced personnel

Outline

Propagation of electromagnetic waves through the system under test

Physical principle of SIMPLe (1/5)

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

SIMPLe is not affected by • Low hydraulic pressure

• Change of diameter of the pipe

• Change of material of the pipe

• Environmental noise

An electromagnetic (EM) signal propagates through the system An electromagnetic (EM) signal propagates through the system under test (SUT)under test (SUT)

The reflected signal is analyzed and processed to extract the The reflected signal is analyzed and processed to extract the desired information on the SUTdesired information on the SUT

SIMPLeSystem under test

Incident

EM signal

Reflected signal

Time domain reflectometry:

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

Physical principle of SIMPLe (2/5)

Sensing element

Physical principle of SIMPLe (3/5)

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

The response of the SUT is influenced by the relative dielectric permittivity, εr, of the material (i.e. the impedance of the

transmission line) into which the EM signal propagates Reflectogram: output of a TDR measurement

The presence of the water leak causes a local variation of the dielectric characteristics which affects the reflected signal

εr, dry soil ~ 3-4 εr, water ~ 78

SIMPLe applied for leak detection of underground pipes:

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

Physical principle of SIMPLe (4/4)Physical principle of SIMPLe (4/5)Bifilar line inserted in a dielectrically-homogeneous material

+

-

d

ρ

Reflectogram

ε1

endinitial point/

connection to instrument

d

ρ

0

local minimumReflectogram

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

Physical principle of SIMPLe (4/4)Physical principle of SIMPLe (5/5)

+

-

Bifilar line in presence of water

ε1ε2

SIMPLe

Already-installed

Metal pipesNewly-installed pipes

made of any material

** patent pending: A. Cataldo, G. Cannazza, E. De Benedetto “Apparatus and method for detection and localization of leaks and faults in underground pipes,” WO BA2011A000 034, June 23, 2011.

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

two major application scenarios for SIMPLe*:

- Same system, different type of sensing element

The sensing element is placed on the pipe at the time of installation of the pipe

Scenario #1:

Application scenarios

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

Scenario #2:

Prototype of SIMPLe

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

A portable case contains all the hardware for SIMPLe

Two different types of sensing element are used for two application scenarios

Sensing element for already-installed metal pipes

Sensing element for newly-installed pipes made of any material

Application Scenario #1Application Scenario #1

Leak-detection in already-installed Leak-detection in already-installed underground, metal pipesunderground, metal pipes

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

Reflectogram

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

Scenario #1: already-installed metal pipes

The pipe must be made of METALLIC (i.e.: conductive)

MATERIAL

Only ONE requirement for scenario #1

Measurement software

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

A dedicated software automatically evaluates (in real time) the position of the leak

Scenario #1: already-installed metal pipes

SIMPLe was also employed on critical operating conditions (i.e., adduction pipe, irregular surfaces, rainy water penetrating in the ground...)

Good performance: excellent candidate as additional option for leak pre-localization

Optimal alternative for leak localization in presence of low pressure, external noise, considerable burial depth

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

Scenario #1: already-installed metal pipes

metallic wire

Application Scenario #2Application Scenario #2

Leak-detection and periodic monitoring Leak-detection and periodic monitoring in «newly-installed» pipes, made of any in «newly-installed» pipes, made of any

materialmaterial

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

The pipe can be made of ANY MATERIAL

The sensing element remains permanently on the pipe and measurement can be performed any time

Only ONE requirement for scenario #2

At the time of installation of the pipe, a biwire must be placed along the length of the pipe

Scenario #2: newly-installed pipes

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

For this scenario, SIMPLe was validated on pilot plants that was specifically equipped with the sensing element.

Scenario #2: Experimental validation

Leaks were provoked at known position, for validating the system.

Water mains (cast iron)

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

Scenario #2: Experimental validation

During installation of the pipe After installation of the pipe

Point for connection to the buried sensing element

Application #2: experimental results

Water mains (cast iron)

Reflectograms acquired in presence of leak

Reflectograms refer to an increasing amount of water escaping the pipe

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

Scenario #2: Experimental validation

Scenario #2: Experimental validation

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

Several other practical cases were tested and explored

Domestic supply pipe (both metallic and plastic)

Distributed sensing elementDistributed sensing element

Application #1: measurement principle

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

Scenario #2: Experimental validation

Water mainsSewer pipes (Gres)

Application #1: measurement principle

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

Typical performance parameters of SIMPLe

Scenario #2

> 6 km/day

0.5 m

1 operator

< 10 minutes

200 m

Scenario #1

Leak detection productivity 2-3 km/day

Leak-localization uncertainty 2-3 m

Required personnel 1-2 operators

Time required for one measurement

< 10 minutes + laid down of the

wireTypical length of inspection portion

200 m

An innovative TDR-based method for pinpointing water leaks in underground pipes

Overcomes some of the limits of traditional techniques: reduction of inspection times, no specific operating conditions needed for the pipe

A single system; two main application scenarios.

- #1 for “already-installed” metal pipes: a useful additional option especially when traditional methods are inapplicable

- #2 for newly-installed pipes, made of any material: can revolutionize leak-detection practices. This configuration may allow periodic monitoring of the pipes

Conclusions

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)

Thank you for your attention

Co-Operation Between A University And A Water Operator In Developing An Innovative System For Identifying And Monitoring Pipe Leaks (S.I.M.P.Le)