Surge Free Systems?

New Opportunities in Monitoring and Analysing Pressure Surges

Dr Ivan StoianovImperial College London, InfraSense Labivan.stoianov@imperial.ac.ukwww.imperial.ac.uk/infrasense

InfraSense Lab

InfraSense Lab: Smart Water Systems• £2.4 million Current Research Budget• 6 PhD students• 2 RA• 9 MSc/MEng students/per annum

fflReservoir

By-pass with check valve

fflSurge (Air) Vessel

Tank(level switch)

AV chamber(air-release vacuum

valve)

Feed tank

Connections / Branched topologyConnections /

Looped topology

Distribution Networks

Pump

Gravity trunk mains

Pumping trunk mains

Pumping

trunk mains

DMA

Surges in Water Supply Systems?

Ageing Infrastructure

Poorly Understood Dynamic Hydraulic Conditions

Pressure Surges:

• Should We Worry? Monitor? Analyse? To what extent?

Surge Modelling: Bursts & Failures of Surge Protection

Design

Pump Optimization

36” main failureHammersmith, July, 2006

Burst prevention

Surge protection

Surge protection (air valves)

Pressure Transients: Other Applications

IC‐DAS v2 & Aquaprobe

Impact on

disinfectant residual,  turbidity

and colour.

? Contaminant Intrusion

? Unsteady Friction

Detection of Bursts & 

Malfunctioning Surge Protection

© 2012 Ivan Stoianov

Surge Modelling and Analysis: Challenges

Modelling Approaches Developed in the 1990sReasonable Results in Simple Topology Systems

Challenges:• Surges: Sources, Amplitude, Frequency• Impact on Fatigue Fracture and Pipe Failure Mechanisms• Verification (Certification) of the Design and Operation of Surge

Protection Devices• Modelling Surges in Systems with Complex Topology• Impact of Pressure and Flow Modulation on Hydraulic Instabilities• Impact of Surges on Discoloration and Chlorine Decay • Safe Implementation of Pump Optimization

Lack of Long-Term High-Frequency Time-Synchronised Dataand Management Tools

Monitoring & Capturing Surges

InfraSense LP:

128S/s, up to 4 simultaneous channels

Continuous sampling for ~ 4 months

5ms time synchronization

Operation since 2010, a rolling programme over four years

200+ installations including DMAs and Trunk Mains

30 billion samples collected

27/01 00:00:00 30/01 00:00:00 02/02 00:00:00 05/02 00:00:00 08/02 00:00:00 11/02 00:00:003

3.5

4

4.5

5

5.5

6

6.5

7

7.5

Time (UTC)

Pre

ssur

e (b

ar)

DAIRYCRESTEAST (G26A)

F

RE

SH

WA

TE

R42

FR

ES

HW

AT

ER

42W

HA

LEB

ON

ELA

NE

WH

ALE

BO

NE

LAN

EW

HA

LEB

ON

ELA

NE

ER

IC19

ER

IC19

MinMaxAvg

Min/Max/Average 14 DAYS ‐ 15min time intervals (SR 128S/s)

DETAIL

~73m

~35m

04/02 03:47:31 04/02 03:49:32 04/02 03:51:33 04/02 03:53:34 04/02 03:55:35 04/02 03:57:34

4.5

5

5.5

6

6.5

7

7.5

Time (UTC)

Pre

ssur

e (b

ar)

MinMaxAvg

Dynamic Hydraulic Conditions SR 128S/s 

120s

~73m

~55m

~41m

04/02 03:43:55 04/02 03:44:10 04/02 03:44:26 04/02 03:44:41 04/02 03:44:57 04/02 03:45:124

4.5

5

5.5

6

6.5

7

7.5

Time (UTC)

Pre

ssur

e (b

ar)

Dynamic Hydraulic Conditions SR 128S/s 

~74m

~40m

~16s

26/02 21:36:00 27/02 02:24:00 27/02 07:12:00 27/02 12:00:00 27/02 16:48:00 27/02 21:36:006

6.5

7

7.5

8

8.5

9

Time (UTC)

Pre

ssur

e (b

ar)

ME01.2 (DUMMY34B)

MinMaxAvg

Dynamic Hydraulic Conditions SR 128S/s 

~87m

~63m

24 hours

25/02 04:55:12 25/02 04:56:12 25/02 04:57:12 25/02 04:58:13 25/02 04:59:13 25/02 05:00:142

3

4

5

6

7

8

9

10

11S0a6 (G0a7)

Time (UTC)

Pre

ssur

e (b

ar)

Dynamic Hydraulic Conditions SR 128S/s

~110m

~25m

Temporal VariabilityRandom response

~180s

Hydraulic Transients in Complex Topology SystemsTransmission Mains

Impact of: • Topology• Demand• Skeletonization

Modelling AccuracyValidation of surge analysis/design

Who do you trust?Who pays for poor surge design? 

Case Study: 60” steel main

21/05 00:00:00 24/05 14:24:00 28/05 04:48:00 31/05 19:12:00 04/06 09:36:00 08/06 00:00:000

20

40

60

80

100

120

140

160

180

200

Time (UTC)

Pres

sure

(mH

2O)

( )

MinMaxAvg

Hydraulic Transients in Complex Topology Systems

15/08 09:07:12 15/08 09:27:21 15/08 09:47:31 15/08 10:07:40 15/08 10:27:50 15/08 10:48:0060

70

80

90

100

110

120

130

140

150

Time (UTC)

Pre

ssur

e (m

H2O

)Purtons AAV Woodford green (BW)

MinMaxAvg

Hydraulic Transients in Complex Topology Systems

~150m

~65m

~15minutes

22/05 15:10:04 22/05 15:14:06 22/05 15:18:08 22/05 15:22:10 22/05 15:26:12 22/05 15:30:1470

80

90

100

110

120

130

140

150

160

170

Time (UTC)

Pre

ssur

e (m

H2O

)Purton AV (BW)

MinMaxAvg

Hydraulic Transients in Complex Topology Systems

~165m

~70m

~15minutes

14/08 15:28:48 14/08 15:36:00 14/08 15:43:12 14/08 15:50:24 14/08 15:57:36 14/08 16:04:4860

80

100

120

140

160

180

Time (UTC)

Pre

ssur

e (m

H2O

)

S001 (G002)

MinMaxAvg

~178m

~65m

~15minutes

Surges & Impact on Failures and  Deterioration Models

Conclusions

Surges DO Frequently Occur

New Opportunities in Monitoring and Analysing Pressure Surges

• Unique technology to monitor the occurrence of surges• Integration of state of art monitoring and modelling tools• Gain confidence in your modelling results

A Significant Factor in Pipe Failures (Fatigue Failure & Fatigue Corrosion)

Dr Ivan Stoianov (ivan.stoianov@imperial.ac.uk)