Pipeline Condition Assessment Technology

Collection Systems Fall SeminarDecember 1, 2016

Presented by: Paul Schumi

gas sewer

waterAsset Management• Pipeline Assessment• Hydrant Assessment• Valve Assessment• Leak Detection• Flushing & UDF

Advanced Solutions• Utilis Satellite Leak Detection

• p-CAT Pipeline Condition Assessment• ArcServer Operations Dashboard

• Cross Bore Elimination• Condition Assessment

• CCTV Condition Assessment• Manhole Inspection• Smoke Testing

Pipeline Condition Assessment using Inverse Transient Pressure Waves

Dr Young-il Kim

Pipeline Condition Assessment Manager / PCAT Team Leader

Detection Services

Director

DS INSIGHT

The pipeline condition assessment challengeCurrent technologies for assessing pipeline condition are often:

• Highly invasive

• Time consuming

• Disruptive

• Costly

• May not give a representative picture of pipe wall condition (average condition over long pipe lengths ≤ 300+ ft.)

Average Condition vs. Sub-Sectional ConditionThe average wall thickness measurement method is simply the average wall condition between two test points.

Sub-Sectional wall thickness (p-CAT) measurement separates the pipe into multiple sections between the two test points into smaller sections (approx. 30 ft. sub-sections).

• This method provides the average for much smaller sections and finding faults that the average wall thickness technique cannot.

Average Condition vs. Sub-Sectional ConditionOften less than 2% of a pipeline is affected by serious corrosion or defects.

Example:

1,500 ft. long section where 1,470 ft. of the pipeline is 85% of its original condition

• And, the remaining 30 ft. is severely corroded to 30% of its original condition

The acoustic method’s average wall condition would provide an averageof 83.5% and report the pipeline as “good”.

Yet the pipe could still experience a catastrophic failure at any time.

Average remaining wall is determined to be 83.5% remaining

using continuous low resolution method(s)

85% wall thickness remaining30ft

83% 83% 83%85% 86% 79% 79%30%76% 86% 87% 87% 89% 86% 86% 79%79%

85% wall thickness remaining

Average Condition vs. Sub-Sectional ConditionThe p-CAT method could identify this corroded section from within the 1500 ft, allowing for targeted repair or replacement and minimising risk while saving considerable cost.

Play Video

Fundamental Physical Mechanisms

There is a correlation between changes in the thickness of metal and cement mortar lining forming a pipeline wall and the speed with which a wavefront from a hydraulic transient propagates along the pipeline.

ΔH = pressure rise following generated transient

H

0

Time

Transient plateau is flat for an undamaged pipeline

Graph showing transient pressure responsewhen wall is damaged

ΔH

Changes in this thickness give rise to reflections which can be theoretically interpreted to obtain a distribution of damage in the pipe.

Fundamental Physical Mechanisms

This theory has been developed into a non-invasive technique which can determine:

• The interior and exterior condition of pipelines including corrosionand cement mortar lining spalling

• Wall loss

• Locations of leaks, air pockets and blockages

• The sealing status of valves, closed valves andcross-connections

Fundamental Physical Mechanisms

𝑎 = 𝐾 𝜌𝑊

1 + 𝐾 𝐸𝑚 𝐼𝐷𝑒𝑒𝑞 𝜓

a = speed of propagation of hydraulic transient pressure wave

K = bulk modulus of water

ρ = density of water

E = Young’s modulus of elasticity of the pipeline wall material

D = internal diameter of the pipeline

eeq = wall thickness of a single material pipeor the total equivalent wall thickness of the composite material pipe

ψ = pipeline restraint factor.

𝑒𝑒𝑞 = 𝑒𝑚 + 𝑒𝑐 ×𝐸𝑐𝐸𝑚

eeq = wall thickness of a single material pipeor the total equivalent wall thickness of the composite material pipe

em = thickness of the metal wall component

ec = thickness of the cement lining wall component

Em = Young’s modulus of elasticity of the metal

Ec = Young’s modulus of elasticity of the cement lining

ID = 727.5mm

es = 4.7mm ec = 12.5mm

OD

= 76

2m

m

Fundamental Physical MechanismsProperties of steel, cement and water at 15C

Es = 210 GPa

Ec = 25 GPa

K = 2.14 GPa

ρw = 999.1 kg/m3

ρs = 7850 kg/m3

γw = 9.8 kN/m3

γs = 77.0 kN/m3

γc = 23.0 kN/m3

νs = 0.30

νc = 0.15

Morgan – Whyalla pipeline testing example

Morgan – Whyalla pipeline testing example

Pressure measurement station (no. 2) at CH 13231 m

CH 0 m

EL 62.5

CCTV camera inspection at

CH 15000 m – 15400 m

Morgan Filtration Plant and Murray River

Pump Station and Storage Tanks

150 mm Morgan Offtake and PRVs at CH 686 m

In-line Gate Valve No.1

CH 183 m

EL 64.0

CH 26100 m

EL 148.1

In-line Gate Valve No.1 (at CH 183 m), No.2 (at CH 1460 m) or No.3 (at CH 7934 m) - CLOSED

No. 1No. 2

Gate Valve No.4

Transient generator

t=1/4” t=3/16”

t=1/4”

t=3/16”

CH 13231 m CH 15627 m

CH 15024 mCH 15709 m

CH 15731 m CH 15839 m

CH 11740 m

Pressure measurement station (no. 1) at CH 15627 m

Transient generation location at CH 15709 m

In-line Gate Valve No.4

In-line Gate Valve No.2

In-line Gate Valve No.3

CH 15024 m

EL 110.0

Cross Connections to Second Pipe at CH 7237 and 7285 m – CLOSED

NOT TO SCALEt = pipe wall thickness

6.5

6.0

5.5

5.0

4.5

4.0

3.5

7.0

15500 15900 1630015100

Ultrasonic wall thickness measurements

2.6

2.9

3.2

3.5

3.8

4.1

4.4

4.7

5.0

5.3

5.6

5.9

6.2

6.5

6.8

Wa

ll T

hic

kn

es

s (

mm

)

7.0

-0.07

-0.06

-0.05

-0.04

-0.03

-0.02

-0.01

0.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

Dim

en

sio

nle

ss

Pre

ss

ure

0.08

15100

15200

15300

15400

15500

15600

15700

15800

15900

16000

16100

16200

16300

Chainage (m)

Avg. wall thickness

Transient pulse

Transient reflections vs. Ultrasonic

Avg. wall thickness Position 1 Position 2 Position 3 Position 4

Position 5 Position 6 Position 7 Position 8Avg. wall thickness

2.6

2.9

3.2

3.5

3.8

4.1

4.4

4.7

5.0

5.3

5.6

5.9

6.2

6.5

6.8

Wa

ll T

hic

kn

es

s (

mm

)

7.0

-0.07

-0.06

-0.05

-0.04

-0.03

-0.02

-0.01

0.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

Dim

en

sio

nle

ss

Pre

ss

ure

0.08

15100

15200

15300

15400

15500

15600

15700

15800

15900

16000

16100

16200

16300

Chainage (m)

Transient reflections vs. Ultrasonic

2.6

2.9

3.2

3.5

3.8

4.1

4.4

4.7

5.0

5.3

5.6

5.9

6.2

6.5

6.8

Wa

ll T

hic

kn

es

s (

mm

)

7.0

-0.07

-0.06

-0.05

-0.04

-0.03

-0.02

-0.01

0.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

Dim

en

sio

nle

ss

Pre

ss

ure

0.08

15100

15200

15300

15400

15500

15600

15700

15800

15900

16000

16100

16200

16300

Chainage (m)

Avg. wall thickness Position 1 Position 2 Position 3 Position 4

Position 5 Position 6 Position 7 Position 8Avg. wall thickness

Transient reflections vs. Ultrasonic

Sections of recovers pipe

Identification of Anomalies

Signal Analysis Overview

No

rmal

ised

Pre

ssu

re H

ead

Var

iati

on

(m

)

5

0

246

-5

247 248 249 250 251

Time (s)

252

AnomaliesSignificant reflection from

large air pocket

• The key benefit of p-CAT is the identification of pipeline anomalies (localised pipeline faults) with approx. 10 m spatial accuracy along a pipeline.

Identification of Anomalies

Detailed Signal Analysis

No

rmal

ised

Pre

ssu

re H

ead

Var

iati

on

(m

)

0.5

0

-0.5

188.5

1

-1

189.0 189.5 190.0 190.5 191.5 192.0 192.5

Time (s)

191.0

A B C D E F

• Anomalies A to F are described in the next table.

Identification of Anomalies

Anomaly Identifier

Approx. Location Interpretation Priority Recommended Action

A 340m from FP2 towards FP3Unknown structural component or air pocket

MediumCheck records to determine if

repair has occurred

B SV4Change in pipe wall thickness

Low None, known feature.

C 153m from SV5 towards FH9 Concrete encasement Low None, known feature.

D 402m from FP10 towards SCV2Unknown structural component or air pocket

MediumCheck records to determine if

repair has occurred

E 18m from SCV2 towards SV5Unknown structural component or air pocket

MediumCheck records to determine if

repair has occurred

F 13m from FP11 towards FH12 Discrete large air pocket HIGHCheck valve operation at pit and

check air valves.

Example summary of anomalies detected in previous plot segment

Valve Sealing

• The status of in-line isolation valves is important for operational effectiveness

• Closed valves in network systems can seriously compromise hydraulic efficiency

• Knowing if a cross-connection between potable and recycled water systems occurs is also important

Evaluation of transient techniques undertaken at Iron Knob

Corroded valve

p-CAT™ - Benefits / Advantages

• Non-Invasive

• Not disruptive

• Minimal or no civil costs required

• Generally minimal or no site preparation required

• Use existing assets to test from (hydrants, air-valves, etc.)

• Distance between fittings can be 3000 ft. or more

2006 – 2016 Field Program

For 27 different clients –

• Such as water utilities, councils, contractors and mining companies

For over 70 different pipeline systems

For over 700km / 450 miles of pipeline

p-CAT™ - Suitability

• Potable water

• Force Mains

Materials:

• CI, CICL, DI, DICL, steel, AC, concrete

• PCCP, theoretically, yes but untested to date

Thank You!

Paul SchumiBusiness Development ManagerHydromax USApaul.schumi@hydromaxusa.com812-708-0590

Jeff GriffithsDirector, Mid-Atlantic RegionHydromax USAjeff.griffiths@hydromaxusa.com757-353-1521