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Leak Detection Sensitivity Calculator

API 1130 & API 1160 SCADA-Based Leak Detection

Leak Detection Sensitivity Calculator (API 1130)
Calculate the minimum detectable leak rate for SCADA-based computational pipeline monitoring (CPM) systems. Enter pipeline parameters, instrument accuracy, and SCADA configuration to determine detection sensitivity, estimated detection time, and false alarm probability.

Pipeline Parameters

in
miles
MSCF/d
psig

Fluid Properties

-

Instrument Accuracy

%
%
°F

SCADA Configuration

sec
pts

Understanding Leak Detection

CPM Systems
Computational Pipeline Monitoring uses SCADA data with mathematical models to detect leaks by identifying imbalances in flow, pressure, or temperature that exceed instrument noise.
Sensitivity vs. Speed:
There is an inherent tradeoff between sensitivity (small leak detection) and speed (quick detection). Tighter thresholds detect smaller leaks but increase false alarm rates.

Formula

MDLR = k × √(u_flow² + u_linepack²)
MDLR = Minimum detectable leak rate
u_flow = Flow measurement uncertainty
u_linepack = Line pack change uncertainty
k = Confidence multiplier (3-5 sigma)

Standards & References

  • API 1130
    Computational Pipeline Monitoring for Liquids
  • API 1160
    Managing System Integrity for Hazardous Liquid Pipelines
  • 49 CFR 195.134
    Leak detection requirements
  • API RP 1175
    Pipeline Leak Detection — Program Management

Engineering Notes

  • Sensitivity: RTTM systems typically achieve 1-3% MDLR, volume balance 3-5%
  • Detection time: Larger leaks detected faster. Small leaks require longer integration time
  • False alarms: Tighter thresholds = more false alarms. API 1130 recommends <1/month
  • Transients: CPM accuracy degrades during operational transients (starts, stops, rate changes)