9 - crockett app presentation

8/9/2019 9 - Crockett APP Presentation

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Leak Detection with

Thermography&

Ultrasonic AcousticsPresented by:

Matthew Crockett, Engineer

Plant Engineering Programs

APP Site Visit

October 30 !o"ember #, $00%


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&ackgro'nd

Detecting leaking fluids, whether it be steam,water or different types of gases, is of major

concern at AEP power plants. These leaking

fluids can affect safety, operation, maintenance,heat rate, and work performance. Detecting leaks

can be difficult in a power plant environment.

AEP has discovered that the combined application

of (n)rared *hermogra+hy and ltrasonic

Aco'stics as part of a plant Predictive

aintenance Program can efficiently identify

leaks in many areas.


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(n)rared *hermogra+hy

!nfrared Thermography "!#$ can be used to detectleaks on the following e%uipment&systems '

(. )eaking Process *alves

+. team Traps

-. ondensers

/. 0eaters1. afety *alves

2. 3oiler asing


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Val"e leakageVal"e leakage

4 !dentifying leaking valves is probably the most effective

use of thermography to reduce heat rate losses and

operational problems.

4 Temperature is key to identifying leaking valves. A smalltemperature rise can indicate a leak through.

4 Piping to a valve should be cool when it has a water leg.

!f the line is hot the valve probably is leaking.

66.5F

396.0F

AR01: >364 .3F

This leaking valve isover (55o "-16o7$.

ost leaking valves

are less evident.


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4 *alves and lines going to the condenser,

boiler blowdown, miscellaneous drain tank,

reclaim tank, drip receiver, and priming for

pumps under vacuum should be checked.

4 All boiler, turbine, stop valve, valve chest,

etc., drain lines need to be checked for leak

through.

4 D8 98T over tighten valves:


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4 All boiler, turbine, stopvalve, valve chest, etc.,drain lines need to be

checked for leakthrough.93.7F

488.6F

100

200

300

400

SP01: 393.3F

)eaking drain

176.6F

667.2F

200

300

400

500

600

SP01: 533.9F

AR01: *598.0F

4 ake sure a valve is

totally closed beforeinspecting.

Turbine reheat steam line drain

valve leaking through.


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Steam *ra+sSteam *ra+s

4 !# can identify leaking

bypass lines andimproper operation "mustmonitor$.

4 8ne must know the trapcycle of operation.

4 omparison between likee%uipment that is

operating the same oftenconfirms problems.

4 ;se ;ltrasonic Acoustics

to confirm problems

118.6F

361.0F

150

200

250

300

350

SP01

team trap stuck open.

80.2F

103.2F

85

90

95

100

SP01

team trap working normally.

team trap by


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Condenser Air (n-leakageCondenser Air (n-leakage4 ondenser air in


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Condenser Air (n-leakageCondenser Air (n-leakage

4 heck all bolts,diaphragms and access

doors on the condenser

and turbine shell.100.9F

116.1F

105

110

115

AR01: 100.8F

AR02: 103.1F

)eaking condenser

e=pansion joint.

)eaking condenser access

cover. 4 ondenser e=pansion jointscan be large source of leakage

but are often difficult to view.;ltrasonic Acoustics is agood alternative method.


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4 *isually these heatervents look alike,

thermally there is a

difference. ool air in


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4 ;sing !# for air in


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.eaters.eaters

4 0eaters can also be checked with !# toidentify heat rate loss items.

4 hell safety valves, vents, drains, and

pumps are items to check during a survey.

4 3oth high pressure and low pressure heatersshould be scanned.

4 *acuum pumps, )P drain pumps, and othertypes should be checked.


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.eaters.eaters

4 *acuum pumps, )P drainpumps, and other types

should be checked.

93.1F

186.4F

100

120

140

160

180

SP01: *156.6F

Shell vent has a vacuu lea!

at the "#$st un#%n %n the l#ne

a"te$ the shell.

4 hell safety valves are a common

leak found. 8nce they begin toleak they normally do not re


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Sa)ety Val"esSa)ety Val"es

4 All safety valves should be scanned.Especially those that do not vent to

atmosphere. Those that vent to reclaim or

miscellaneous drain tanks are oftenoverlooked. 0igh energy piping safeties are

usually reset during outages and vent to

atmosphere.


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&oiler&oiler

4 !nfrared is very effective when used to identifyboiler and ductwork casing leaks.

4 3oiler casing leaks increase au=iliary power

use by increasing load on fans and [email protected] #educing casing leaks improves combustion

and reduces e=cess air.

4 Total air flow is often reduced "especially onbalance draft units$ which decreases emissions

since precipitators, #s and 7Ds treat less

e=it gas.


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&oiler&oiler

4 asing leaks such as this one can be easily

identified with infrared.

SP01


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ltrasonic Aco'stics ;ltrasonic Acoustics ";A$ can be used to detect

leaks on the following e%uipment&systems '

)eaking Process *alves team Traps

ondensers afety *alves

0ow ;ltrasonic Acoustic )eak Detection >orks

During a leak, a fluid "li%uid or gas$ moves from a highpressure to a low pressure. As it passes through the leaksite, a turbulent flow is generated. This turbulence hasstrong ultrasonic components which can be heard with

speciali@ed detection e%uipment.


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4 ;ltrasonic Acousticsre%uires skilled personnel with

the proper training.4 >hen used to detect piping leaks it can be effective to

pin point small sources.

4 )arge leaks and background noise can BoverwhelmCmany detectors and re%uire continual adjustments to

find the source. ;ltrasonic Acoustic re%uires turbulent

flow between low and high pressure sources.

4 *acuum leaks sound different than pressure leaks andan e=perienced user can differentiate between the two.

4 hielding of the detector is a useful tool to eliminate

background noise.

ltrasonic Aco'stics


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ltrasonic Aco'stics4 !nspection methods vary depending on the type of valve or steam trap.

Therefore the primary rule is to know the way a specific trap or valve maywork under specific conditions.

4 To determine trap&valve conditions such as leakage or blockage'

(. Touch upstream of the valve or trap with a contact waveguide probeand reduce the sensitivity of the instrument until the meter&display

panel reads about 16 of scale. !f the instrument has fre%uency tuning,you may also use this feature to hear the trap or valve sound %ualitymore clearly. Tune the fre%uency until the sound you would e=pect tohear becomes clear.

+. 9e=t, touch downstream of the valve or trap and compare intensity

levels. !f the sound is louder down stream, the fluid is passing through.!f the sound level is low, the valve or trap is closed.

-. >hen recording decibel levels and trending make all settings on theultrasonic instrument repeatable.


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ltrasonic Aco'stics

4 Test Point A 16 db

4 Test Point 3 /6 db

4 Test Point (5 db

4 Test Point D F db

E=ample of a

ood *alve


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Per)orming A S'r"eyPer)orming A S'r"ey

4 To perform an accurate and effective !nfraredThermography or ;ltrasonic Acoustic survey takes

training on the e%uipment, planning of what is to be

surveyed, a method of progression, and a knowledge of

the systems involved.

4 !f not trained in the use of this e%uipment then seek

assistance.


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Per)orming A S'r"eyPer)orming A S'r"ey/'estions +rior to a s'r"ey

(. cope of surveyH+. Do you have safe access to perform the inspection and what

Personal Protection E%uipment is neededH

-. Does the e%uipment&systems need to be placed in serviceH >hat

other conditions need to be metH/. !s the e%uipment operating such to give meaningful resultsH

1. >ill it be cost effective to perform the inspectionH

2. >ill you be needing additional resources to perform the

inspectionH5. an you take advantages of other technologies or procedures tosupplement the findings of the inspectionH

F. >hen are the results needed&e=pectedH


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AnalysisAnalysis

4 Analysis should be done in a systematic

repeatable format.

4 Determine the baseline or other industryaccepted standards.

4 Document source of acceptance criteria.4 Problems or anomalies should be reviewed

for determination as to what corrective

actions, if any is re%uired.4 Problems should be itemi@ed and prioriti@ed

according to severity, cost, location or otherprocess specific criteria.


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e+ortinge+orting

Accurate reporting should include the following'

(. over )etter&E=ecutive ummary

+. pread sheet of events sorted according to severity

-. Time&Date&;nit onditions

/. E%uipment identification

1. )ocation&Diagram

2. pecific problem details with priority

5. orrective action recommended "if any$F. Problem action criteria "everity$

?. *isible Photograph&!# !mage&;ltrasound Plot

(6. !nspectors 9ame


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*raining1E2+erience*raining1E2+erience4 The %uality of a Thermography or ;ltrasonic Acoustic survey

depends upon training and e=perience.4 8nly trained individuals should perform these surveys.

4 Training can be I!n


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ummary

!nfrared Thermography and ;ltrasonic Acoustics

both provide accurate detection of fluid leaks

that commonly occur at a power plant.

>hen combined, the effectiveness of these leak

detection methods increases dramatically.onfirming a suspected leak detected with one

technology by repeating the detection with a

separate technology is always a best practice.Proper reporting of findings is key to the

successful application of these technologies.


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KuestionsH

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