Post on 23-Dec-2015
CAVLAR®
Ilse Pieterse-Quirijns
400 mm NGIJ400
mm
NG
IJ
Valve failure III
500 mm GGIJValve failure II
300 mm GGIJ
Known valve failure
Mains replacement
• Failure of valves:– I (known): 2 extra valves, no
extra customers– II: 4 extra valves plus extra
customers– III: 5 extra valves plus extra
customers
Valves can fail
CAVLAR®
• Quantifying the contribution of valves (or the fialure of valves) to the supply of drinking water
CAVLAR®
CAVLAR® :
Criticality Analysis Valve Locations And Reliability
Location valves: section analysis of distribution network
Reliability of valves: calculate performance distribution net
critical sections
critical valves
Effect of valve maintenance: improvement valve reliability
improvement of performance distribution net
1
2
3
CAVLAR®: required input
Required information:
• LIS data:
• Failure data:
• Maintenance data:
Volendam
number of connections, length, diameter
failure probability
supply interruption durance
valve reliability
Insight in existing distribution net
0
50
100
150
200
0 1 2 3 4 5 6 7 8 9 10
Num
ber
of
sect
ions
Number of valves per section
0
1000
2000
3000
4000
0 100 200 300 400 500 600
Leng
th p
er
sect
ion (
m)
Number of sections
0
50
100
150
200
0 100 200 300 400 500 600
Connect
ions
per
sect
ion
Number of sections
0.001
0.01
0.1
1
10
100
1000
0 100 200 300 400 500 600
Volu
me p
er
sect
ion (
m3
)
Number of sections
Location of valves
Section:
number of connections
diameter
length
failure probability
Valve:
Reliability
Section diagram
Adjust valve configuration
Adjust valve configuration (2)
New valve locations: comparison of configurations
number of valves per section
020406080
100120140160180200
0 1 2 3 4 5 6 7 8 9 10
number of valves
nu
mb
er o
f se
ctio
ns
Original configuration
New configuration
number of connections in a section
0
50
100
150
200
250
300
350
400
0-20
21-4
0
41-6
0
61-8
0
81-1
00
101-
120
121-
140
141-
160
161-
180
181-
200
number of connections in a sectionn
um
ber
of
sect
ion
s
less dependent sectionsnew config.:
less valves in a section
50% of valvesmore connections in a sectionnorm Groningen:< 200
33% of sections
Reliability of valves: critical sections (1)
• For each section CAVLAR® calculates performance indicators at a certain valve
reliability:
• Impact : number of connections
• Ratio : impact/number of connections in section
• CML (min/section/year) : minutes that costumer does not have water
• CI (1/year) : customer interruptions
highest CML critical sections
Performance indicator:ImpactRatio
CICML
critical sectioncritical valves
Reliability of valves: critical sections (2)
159 conn.3 valves
I = 181Ratio = 1.138CML = 06:54:08CI = 0.042vave rel.=0.90
Critical
section 1:
A_123Y
Reliability of valves: critical sections (3)
Reliability of valves: critical sections (4)
First 10 (5%) sections: 24% of total CML
First 22 (10%) sections: 40 % of total CML
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
90.00%
100.00%
0 50 100 150 200 250
number of sections
per
cen
tag
e o
f C
ML
Reliability of valves: critical sections (5) Judge new valve configuration based on CML
number of valves reliability number of sections CML [min]
original configuration 712 0.90 555 5:01
new configuration 333 0.90 183 11:56
new configuration + maintenance
333 0.95 183 9:42
x 0.5 x 0.33 x 2.3
CML improvement: 18.7%
weight reduction operational costs and CML increase
optimalisation valve configuration
Influence of increased valve reliability
0:00:00
0:07:12
0:14:24
0:21:36
0:28:48
0:36:00
0:43:12
0:50:24
0.7 0.8 0.85 0.9 0.95 0.98 1
valve reliability [-]
CM
L [
min
/co
nn
./ye
ar]
original configuration
new configuration
Effect of valve maintenance: Judge maintenance scenarios
Maintenance of valves:
• increase of valve reliability 0.90 0.95 effect maintenance for Winschoten: improvement CML with 18.7%
• CAVLAR® determines prioritization of valves
(ranking valves with diminishing effect on performance of distribution net)
input for maintenance scenarios
Effect of maintenance on CML maintain 50% of
most critical valves
75% of max.
possible result
same effect with
maintenance of
22% of most
critical valves to
higher reliability
btbh 0.95
btbh 0.98
willekeurig naar 0.95
0.0%
5.0%
10.0%
15.0%
20.0%
25.0%
30.0%
0% 20% 40% 60% 80% 100%
percentage valves
imp
rove
men
t C
ML
vs
0.90
Conclusion
Roll of CAVLAR®: tool for optimisation of distribution network tool for prioritisation of sections and valves tool for advise in maintenance plans
1
2
3
Smart maintenance: good maintenance of critical valves results in
same performance
Smart configuration: judgement and optimisation of valve configuration