Fitness For ServiceAn Overview for HL Pipelines

Larry SheltonManager, Asset IntegritySunoco Logistics, L.P.December 11th, 2012 - THLPSSC

Ideal World of HL Pipelines:

• API 5L with 100% Quality Control

• Design and construction to B 31.4

• 49 CFR 195, Subpart E, Hydrostatic Pressure Test to set MOP

• Traceable, Verifiable, and Complete Records

• Pipe fully protected from the environment

• Steady operating pressure

Real World:

• Older manufacturing, design, and construction techniques

• MOP may not have been established by Subpart E

• Records may not be complete

• Environmental threats

• Pressure cycles

So, how can we know that a pipeline is in a safe condition to operate?

In other words, how do we know that a pipeline is fit for service?

Fitness for Service

The condition of being suitable for an intended service, and maintaining that

suitability through the intended period of service.

Fitness for Service Assessment:

A quantitative engineering evaluation performed to determine the level of integrity (fitness) of an in-service component that may

contain a flaw or damage.

Applied in many safety-sensitive industries

• Nuclear Power

• Refining & Petrochemicals

• Aircraft, especially airframes

• Space vehicles

• Medical appliances

FFS Assessments

• A multi-disciplinary engineering analysis to determine whether equipment is fit for continued service over a desired period of time

• Components may contain flaws, not meet current design standards, or be subjected to more severe operating conditions than assumed in the original design basis

• FFS assessments consist of standard analytical methods to assess flaws and damage, quantify them, and predict their development over time

• To the extent practicable, analysis is quantified. When it cannot be accurately quantified, the most conservative reasonable boundary is assumed. Additional safety factors may also be applied.

FFS assessment leads to a decision:

• Continue service with no further action (Sometimes a design imperative)

• Continue service; monitor at specified interval• De-rate• Modify• Repair• Replace• Abandon

Critical to FFS Assessments:

• Understanding the set of “Damage Mechanisms” to which the component may be subject

• Their etiology and development must be understood

• A measurement system to quantify them• Knowing time-dependence and current condition

are necessary to determine remaining life• Generally, these are already well-established with

regard to pipelines

API Standard 579/ASME FFS-1 Fitness For Service

• Standard for FFS assessment of flaws and damage associated with in-service operation of plant pressure vessels, piping, and tanks

• Driven by OSHA 1910 Process Safety Management requirements

• Refineries and petrochemical facilities have a wide variety of damage mechanisms

• FFS-1 addresses each with prescribed evaluation processes and guidance for decision-making

• Also provides the technical basis for FFS assessment • Some application to transmission pipeline assessment

FFS principles already at work in the HLP industry:

• 49 CFR 195.303 – Risk Based Alternative to Hydrostatic Pressure Testing

• 49 CFR 195.452 – Integrity Management Programs

• API 653 – Above Ground Storage Tank Inspection

• Determining seam susceptibility to cracking

• Fatigue analysis

Risk-Based Alternative (RBA)

• A decision-making process to determine whether a given pipeline requires a hydrostatic pressure test to establish Maximum Operating Pressure

• Weighed factors of documented operating history, pipe condition, and risk of failure

• Led to a determination that a pipeline could be operated safely, or required further evaluation on a prioritized schedule, or that RBA was not appropriate and hydrostatic testing was required

• Requires annual review of the risk factors

• Establishes a minimum desired operating interval• Prescribes testing and evaluation to confirm FFS

for the period• Integrates data to determine the damage

mechanisms for a particular segment• Sets safe limits for damage mechanisms• Provides for shorter, or longer, intervals as

indicated by engineering analysis• Drives decision-making for safe continued service

IMP as FFS

CONCLUSION….

• FFS assessment is a widely accepted and applied model for quantifying flaws and determining the remaining life of a safety-sensitive component

• FFS is already being applied in the HLP Industry• Understanding damage mechanisms are critical to

successfully applying FFS • Technology continues to improve our ability to

effectively apply FFS• FFS greatly enhances risk management by replacing

assumptions with qualitative analysis– Real risks identified through FFS assessments– Resources can be redirected from over-conservative

assumptions to real risks

Questions? Comments?