Sam Gordji, samgordji@yahoo.com Obtaining PD ,PFA , and Other Important Parameters For Pipeline Leak Detection System Sam Gordji, samgordji@yahoo.com To obtain a copy of “Standard Test Procedures for Evaluation Leak Detection Methods: Pipeline Leak Detection Systems”, please visit: http://www.epa.gov/swerust1/ustsystm/pipe.pdf Or http://www.nwglde.org/protocols.html Instructor’s guide is a part of this seminar and is called Semsas1.doc

Definitions Noise: A random variable, fluctuation in measurement due to temperature, pressure, and other factors Signal, a leak, e.g. .1 gph, .2 gph, etc. Signal-plus-noise, when the signal is added to the noise LR, leak rate Threshold, a location between the zero leak rate and a specific leak rate, usually half way between the above two locations The calculation of the PFA , the PD, and other parameters of special importance since they appear in all the protocols

Noise Only Cumulative Frequency Distribution (CFD)

-.1 Is Added to Every Test Results This Is the CFD for a Leak Rate of -.1 gph

When the Noise Is Added to the Signal

Deleting the two Lower and One Higher Observations

For the Same Data Changing the LR to -.20 From -.1

Page A-6 of SIR Protocol

With Leaking Tank Out of the Picture We Have

Conclusion When testing, it is really important to ensure that the instruments are working correctly and we have non-leaking pipelines As seen from the data, larger variation in the measurements the “random noise” causes problem and decrease the PD and increase the PFA Please email your question to: samgordji@yahoo.com Thank you