Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
API RP 1170-2015: Technical Requirements and Implementation for Pipeline Leak Detection Programs
Navigating the Recommended Practice for Effective Leak Detection System Design and Program Management
API RP 1170-2015, titled “Design and Operation of a Commercial Pipeline Leak Detection Program,” provides a comprehensive framework for pipeline operators to develop, implement, and maintain effective leak detection programs for onshore hazardous liquid pipelines. This recommended practice (RP) consolidates decades of industry experience, offering actionable guidance on system selection, performance evaluation, and program management to minimize the risk of undetected leaks and reduce environmental impact.
Scope and Applicability
The RP applies to operators of commercial onshore pipelines transporting hazardous liquids such as crude oil, refined petroleum products, liquefied petroleum gases, and anhydrous ammonia. It covers both new pipeline systems and existing pipelines, with a focus on continuous improvement. While primarily intended for onshore systems, many elements can be adapted for offshore and gas pipelines with operator discretion. The document addresses the entire leak detection program lifecycle: design, implementation, operation, maintenance, and performance improvement.
Technical Requirements and Key Provisions
Leak Detection System Design
API RP 1170-2015 emphasizes a risk-based approach to system design. Operators must consider pipeline characteristics—diameter, length, pressure, product composition, and operating modes—as well as environmental and population sensitivities. The RP advocates for a combination of internal and external leak detection methods to provide robust coverage.
Internal systems, often implemented via SCADA and computational pipeline monitoring (CPM), use real-time data to detect mass imbalances or pressure anomalies. External systems, such as vapor sensors, acoustic monitors, and soil sampling devices, provide localized leak detection. The selection of specific technologies should be guided by a formal risk assessment that identifies potential leak scenarios and evaluates system effectiveness.
Important: Relying solely on a single detection method may not meet the RP’s intent for program robustness. A defense-in-depth strategy is recommended.
| System Type | Method | Typical Sensitivity | Application |
|---|---|---|---|
| Internal | Mass Balance | 1–5% of flow | Liquid pipelines |
| Internal | Pressure/Flow Monitoring | 2–10% of flow | Batch and liquid pipelines |
| External | Acoustic/Ultrasonic | Very high (small leaks) | Gas and liquid pipelines |
| External | Cable/Water Sensing | High | Buried pipelines |
| External | Vapor/Leak Detection | High | Liquid pipelines in sensitive areas |
Performance Metrics
The RP introduces key performance indicators (KPIs) to quantify leak detection capability. These include:
- Detectability – The smallest leak that the system can consistently identify under specified operating conditions.
- Reliability – The probability that the system detects a leak when one occurs, balanced against the false alarm rate.
- Robustness – The system’s ability to maintain performance across a range of conditions (e.g., during batch changes or transient operations).
- Sensitivity – A measure of the system’s ability to detect small leaks.
- Response Time – The interval between leak initiation and operator notification.
Operators are expected to establish target values for each KPI based on risk analysis and to validate them through performance testing. API RP 1170-2015 recommends conducting blind leak tests and system assessments at least annually.
Program Management
A formal program management structure is essential. The RP requires:
- Assignment of a program owner with clear authority and responsibility.
- Development and maintenance of a leak detection program document that includes system descriptions, operating procedures, maintenance schedules, and training plans.
- Implementation of a management of change (MOC) process for any modifications to systems