Transcript Gas leaks are a part of our business and it is how you

Western Regional Gas Conference
2007
Effective Leakage Management
Ronald Six
Senior Utility Consultant
Loss Control Division
AEGIS Insurance Services, Inc.
201/417-2487
[email protected]
A
AE E GG II S S
ssociated
lectric
as
nsurance
ervices
AEGIS
Background Information
• Utility Mutual Insurance Company
(member owned)
• Formed in 1975 by 22 gas utilities
• Electric Utilities began joining in 1977
• 490 members – 95% utilities and related
energy
Gas leaks are a part of our
business and it is how you
manage them that depends on
whether
you are making sound
business decisions.
Remember, they are not going
to fix themselves and they will
get bigger.
Detect
Pinpoint
Repair
Reasons We Conduct Gas
Leakage Surveys
Federal & state requirements
Reduce unaccountable loss
Overview of the system
Reduce operating costs
Public image
Public Safety
CFR 49 192.723
Distribution System: Leakage Surveys
(a) Each operator of a distribution system shall
conduct periodic leakage surveys in
accordance with this section.
(b) The type and scope of the leakage control
survey must be determined by the nature of
the operations and the local conditions, but
must meet the following minimum
requirements:
System Review
• Annual
– Business district/Critical Areas
– Public buildings
• Scheduled Rotation
–
–
–
–
Residential
Steel CP Protected
Plastic pipe
Bare Steel-Unprotected areas
Special Surveys
• Cast iron
• High leak frequency areas
• Construction areas
• Blasting areas
• Pre-paving
• Other
Surface Sampling Survey Methods
Mobil (HFI or OMD) Portable (HFI or Laser)
Remember:
• The above methods are search tools
• The leak must be verified & classified
Equipment Needed To Conduct
A Leakage Detection Survey
• Surface sampling detector (HFI) other
approved instruments
• Combustible gas indicator
• Probe bar
• Maps/pipe locator
• Leakage detection forms
• Calibration/verification equipment
• Trained operator
Identifying Gas Leaks By
Vegetation Damage
• Visual vegetation
damage indications
should still be taught
as part of the leak
survey process.
• Vegetation is a keen
indicator and it is
becoming a lost art.
Mobile Leak Detection
Evolution
OMD™ Optical Methane Detector
Portable Hydrogen Flame
Ionization (HFI) Instruments
• Search tool
• Visual and audible
indication of gas
concentrations in
ppm
• Indications must be
confirmed with a
Combustible Gas
Indicator (CGI)
Remote Methane Leak Detector


Tunable diode laser absorption spectroscopy
Laser



Methane only




Infrared
Green sight
absorbs portion of light
Ppm-m
Range – 100 feet
Through windows
Are you conducting a
“leakage control survey”
or a
“controlled leakage survey”?
Factors To Consider When
Conducting The Survey
• Line pressure
• High vs. low
• Line location
• Maps, pipe locator
• Soil moisture
• Wet, dry, frost
• Type of cover
• Paved vs. grass
• Wind conditions
• Calm vs. windy
• Instrument
• Calibrated
• Operator
• Observant
Surface Sampling Indications
Must Be Confirmed
• No matter the
degree of
sophistication, all
surface sample
indications must be
confirmed and
classified with CGI
and probe bar.
Audits of Leak Surveys
• Audits of the leak surveys should be performed to
verify that the leaks are being detected.
• Audits should also include the comparison of the
leaks generated by the public vs. leaks detected by
the leakage detection survey.
• It is critical that the survey is detecting all hazardous
leaks as well as those of economic importance.
• Annual checks of transmission line Class Areas,
Public Buildings/Critical Areas and Survey Types i.e.
mobile vs. portable should be conducted and
updated as necessary.
GPTC Guidelines
Leak Classification
• The following establishes a criteria by
which leakage indications of flammable
gas can be graded and controlled. When
evaluating any gas leak indication, the
initial step is to determine the perimeter
of the leak area. When this perimeter
extends to a building wall, the
investigation should continue into the
building.
GPTC Guidelines
Grade 1 Definition
• A leak that represents and existing or
probable hazard to persons or property,
and requires immediate repair or
continuous action until the conditions are
no longer hazardous.
#404
#402
Concrete Sidewalk
90% Gas @
Curb
8” CI UP
OLD MAIN STREET
#400
30% Gas @
Foundation Wall
CURB LINE
ASH STREET
6” Steel UP
20% Gas In Telephone Manhole
GPTC Guidelines
Grade 2 Definition
• A leak that is recognized as being
non-hazardous at the time of detection,
but justifies scheduled repair based
on probable future hazard.
• GPTC rechecked every 6 months.
GPTC Guidelines
Grade 3 Definition
• A leak that is non-hazardous at the time
of detection and can be reasonably
expected to remain non-hazardous.
• GPTC rechecked once each year.
Pinpointing
Is not an exact science.
It is a developed skill which
is learned and perfected
through your mistakes
and your successes.
• Centering = Where is the gas?
• Pinpointing = Where is the leak?
• The leak must be centered
before it is pinpointed
SAVE
ANOTHER
MISSED
EXCAVATION
Consistency = Success
SAME
• Exact location of main, services etc.
• SAME size of test hole (aeration is the key)
• SAME depth of test hole (must be consistent)
• SAME location of test holes (same side of main)
• SAME instrument use (consistency in testing)
60% Gas
Curb
8” Steel UP CWP
0%
10%
40%
35%
45%
50%
50%
15%
50%
Maple Street
15% Gas
Service
Line
45%
0%
Using The Soil Purger In
The Pinpointing Process
• Purge from a hole where you know
that the leak is not
• Plug holes near purge point
• Dense soil or moisture –
time the purge/purge each hole
• Use it only when all other methods have
failed
Audits of Pinpointing & Repair
• Grade 1 leaks-you must be absolutely sure
that the conditions that got you there are
no longer present when you leave.
• Auditing hit to miss ratios i.e. “dry holes”.
• Are the leaks being pinpointed by a
dedicated pinpointing crew or are they
being pinpointed by the crew making the
repair?
• Are rechecks of repairs being performed?
• Odor complaint investigations
…begin with a call
• An odor complaint call should
be considered a Grade 1 leak…
until proven otherwise.
The Key Is Listening
• Not every call is a gas
emergency
• Listen to the customer
and ask questions in
order to gather the
information needed
Is It Static Or Dynamic?
Where is the odor? =
At gas range vs. throughout
How long smelled? =
For a week vs. just noticed it
How strong is the odor? =
Barely smell vs. making me sick
Can you hear anything? =
No vs. hissing sound
Anyone moved recently? =
No vs. apartment next door moved
Any plumbing done? =
No vs. husband just installed range
Any construction in area? =
No vs. backhoe digging out front
Auditing Call Center Programs
• Are all odor complaints being dispatched
immediately?
• Are they being dispatched to the proper
personnel?
• Are pertinent times i.e. call received,
dispatched, arrival, makesafe being
recorded and tracked?
• Is proper information being forwarded to
the First Responder?
Remember:
The Job Is Not Completed
• Until all paperwork/documentation
is completed:
– Neatly
– Thoroughly
– Accurately
• You may do everything right, but you
may be judged by what is or is not
documented
Our main job is not
finding & fixing leaks
Our main job is
public safety
AEGIS Insurance Services, Inc.
Thank You
Please visit our website @
aegislink.com