addressing uncertainty in oil and natural gas industry greenhouse
addressing uncertainty in oil and natural gas industry greenhouse
addressing uncertainty in oil and natural gas industry greenhouse
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Appendix C<br />
OPERATING CONDITIONS, INSPECTION, CALIBRATION<br />
AND EXPECTED UNCERTAINTIES FOR COMMON FLOW METERS (cont<strong>in</strong>ued) a<br />
METER TYPE MEDIUM OPERATING CONDITIONS INSPECTION & CALIBRATION UNCERTAINTY b<br />
Venturi meter<br />
Gas <strong>and</strong><br />
Liquid<br />
− No corrosive <strong>gas</strong>es <strong>and</strong> liquids − Annual calibration: pressure<br />
transmitter<br />
− 20-100% of the<br />
measurement range: 1.5%<br />
(Expected life span: 30<br />
years)<br />
− Calibration: entire measurement<br />
<strong>in</strong>strument – once per 5 year<br />
− Annual: visual <strong>in</strong>spection<br />
− Annual ma<strong>in</strong>tenance accord<strong>in</strong>g to<br />
general <strong>in</strong>structions for<br />
measurement pr<strong>in</strong>ciple<br />
Ultrasonic meter<br />
(Expected life span: 15<br />
Gas <strong>and</strong><br />
Liquid<br />
− Transducer assembly to be<br />
replaced accord<strong>in</strong>g to the<br />
manufacturer’s specifications<br />
− Clean<strong>in</strong>g: once per 5 years,<br />
recalibration <strong>and</strong> adjust<strong>in</strong>g, if<br />
necessary<br />
− 1-100% of the measurement<br />
range: 0.5%<br />
years)<br />
− No disturbances <strong>in</strong> frequencies − Annual <strong>in</strong>spection<br />
− Composition of flow<strong>in</strong>g<br />
medium should be known<br />
o Contact between transducer<br />
<strong>and</strong> tube wall<br />
− Ultrasonic meters guidel<strong>in</strong>es: o Wall corrosion<br />
Vortex meter<br />
(Expected life span: 10<br />
years)<br />
o<br />
M<strong>in</strong>imum of 10D free <strong>in</strong>put<br />
flow length before the<br />
meter, <strong>and</strong><br />
o M<strong>in</strong>imum of 5D after the<br />
meter<br />
Gas − Set-up is free of vibration<br />
− Avoid compressive shocks<br />
− Vortex meters guidel<strong>in</strong>es:<br />
o M<strong>in</strong>imum of 15D free <strong>in</strong>put<br />
flow length before the<br />
meter, <strong>and</strong><br />
o<br />
M<strong>in</strong>imum of 5D after the<br />
meter<br />
−<br />
−<br />
−<br />
−<br />
o Transducers<br />
Annual ma<strong>in</strong>tenance accord<strong>in</strong>g to<br />
<strong>in</strong>structions of manufacturer/<br />
general <strong>in</strong>structions measurement<br />
pr<strong>in</strong>ciples<br />
Clean<strong>in</strong>g: once per 5 years,<br />
recalibration <strong>and</strong> adjust<strong>in</strong>g, if<br />
needed<br />
Annual <strong>in</strong>spection of: sensors,<br />
bluff body, <strong>and</strong> wall corrosion,<br />
Annual ma<strong>in</strong>tenance accord<strong>in</strong>g to<br />
general <strong>in</strong>structions for<br />
measurement pr<strong>in</strong>ciple<br />
a Based on material presented <strong>in</strong> the ETSG, July 2007 document <strong>and</strong> the sources cited with<strong>in</strong><br />
b<br />
R<strong>and</strong>om errors are based on experience of operat<strong>in</strong>g the respective flowmeters under designated <strong>in</strong>stallation, operation, calibration, <strong>in</strong>spection <strong>and</strong> ma<strong>in</strong>tenance procedures.<br />
−<br />
10-100% of the<br />
measurement range: 2%<br />
Pilot Version, September 2009 C-2
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