Why the differences in All versus the Closest Tower

Owned by Joseph Pikas
Last updated: Dec 09, 2022
2 min read

ACPT Fault calculations allow the user to select ALL or a Specific Tower to assess the voltage across coating and the current on the pipe. Why the differences?

  • Selecting the closest tower to pipeline results in a more accurate assessment of the fault to the pipeline

  • Selecting ALL towers results in a general pattern of the voltages and currents across the length of each segment being assessed.

It should be noted, that the Arc Distance is uniform value across each section for the entire length of the segment under study.

ACPT Fault calculations are based on the map Centerline of Tower and Pipeline (See Example Below). The geometric measurements of the tower are needed for this assessment.

·        Conductive Faults dissipate directly from tower grounds to earth onto the pipe (Also call Resistive Faults and are of greater intensity).

·        Inductive Faults dissipate along the shield wires and grounds to earth.  (Less intensity compared to a conductive fault).

·        Pipeline centerline distance for section fault 63.73 feet from center line of tower (Calculated by ACPT)

·        Arc Distance is 18.09 feet (Calculated by ACPT) – Must be measured from the closest leg or legs of the tower

Centerline distance of tower to closest leg to pipeline (Measurement determined by User)  25’

·        To determine if a fault condition is threat using closest tower leg to the pipeline:

o   Calculate Distance from Centerline to Pipeline (63.73’) minus Inputted User closest leg (25’) = Actual Distance to Pipeline (36.63’)

o   Calculate Actual Leg Distance to Pipeline (36.63’) minus Arc Distance (18.09’) = Outside Influence of Arc Distance (18.54’)

Example of a Section to Calculate Arc Distance from the Closest Tower Leg