Piping and Pipelines Assessment Guide

Dedication

Preface

Chapter 1: An Introduction to In-plant Piping and Pipeline Fitness-for-Service

Introduction

What Is Piping?

Areas Where Corrosion Attacks Piping

The Maximum Allowable Operating Pressure (MAOP)

Assessment Procedure

Classification of Corroded Regions

Corroded Pit Region Interaction Parameters

Methodology

Determining the Allowable Length of Corrosion

Corrosion Allowance

Assessing Type 3 Flaws

Burst Tests Validation

Circumferential Corrosion

Corrosion in Pipe Bends

Branch Connections and Fittings

Determining a Maximum Allowable Operating Pressure

Flaws in Heat-Affected Zones of Welds

Chapter 2: An Introduction to Engineering Mechanics of Piping

Piping Criteria

Stress Categories

Allowable Stress Range for Secondary Stresses

Stresses Acting on Piping Elements

Stress Calculations

The Pipeline Codes—ASME B31.4 and B31.8

Flexibility and Stiffness of Piping

Stiffness and Large Piping

Flexibility Method of Piping Mechanics

Criteria for Flexibility Analysis

Example Using the Empirical Flexibility Criterion

Suggested Criteria for Level of Piping Flexibility Analysis

Closure

Chapter 3: Fitness-for-Service Topics of Local Thin Areas, Plain Dents, Dents-Gouges, and Cracks for Piping

Useful RSF Equations Using API 579

Assessment Techniques and Acceptance Criteria

Remaining Life Assessment

Remediation

In-Service Monitoring

Documentation

Damage Mechanisms

Blisters and Laminations

Assessment of Local Thin Areas

General Metal Loss Assessment

Local Metal Loss Assessment

Performing the Remaining Life Assessment

Material Property Data

Crack-like Flaws

Grooves, Plain Dents, and Dents with Gouges

Plain Dents

Dents and Gouge Combination Type Flaws

Chapter 4: Fitness-for-Service for Brittle Fracture Concerns

Introduction

Brittle Fracture Concepts

Definitions

Safe Operation at Low Temperatures Existing Equipment

Example 4-1 Determining the Basic MAT and Constructing the MAT Curve

Determining the MAT Using Fracture Mechanics

Variations to MAT

Charpy Exemption Pitfalls—Words of Caution

Welding

Considerations for Design Codes Other Than ASME

Selecting Materials and Defining Impact Requirements—New Piping and Components

Managing Potential CET Violations

Cases of Brittle Fracture

Transient Thermal Stresses

Example 4-2 Thermal Transients in a Pressure Relief Piping System

Chapter 5: Piping Support Systems for Process Plants

Spring Supports

Piping Nozzle Loads on Rotating Equipment

Nozzle Stiffness and Elastic End Conditions

Piping Systems Without Springs

Fluid Forces Acting on Piping Systems

Nozzle Movements and Thermal Displacement

Residual Heat Transfer Through Pipe Shoes

Chapter 6: Piping Maintenance and Repairs

Leaking Pipe Flanges and Hot Bolting

Leak Sealing by Banding Flange or Wire Seal Peripheral Seal Repair

Bolted Pipe Clamps

Flange Insert Clamps (Insert Ring or Tongue Clamps)

Clamps with Thrust Loads

Sealants

Repairs Involving Hot Work

Equipment Isolation Repairs—Stoppling

Equipment Isolation Repairs by Freeze Sealing

Closure—Threaded Connections

Chapter 7: Hot Tapping (Pressure Tapping) and Freezing

The Hot Tap Process

Assessing the Feasibility of Hot Tapping

Special Considerations for Welded-on (Hot Work) Hot Taps

Hot Tap Design Considerations

Wall Thickness of Header Pipe

Test Pressure and Temperature

The Hot Tap Package

Freeze Sealing

Chapter 8: Pipeline Fitness-for-Service, Repair, and Maintenance—Selected Topics

Useful RSF Equations Using API 579 Methodologies

API 579 Criteria Modified to Pipelines

Grooves, Plain Dents, and Dents with Gouges and Crack-like Defects

Repair Options for Pipelines

Hydrogen Attack

Soil-Structure Interaction Abnormality of Pipe Bowing

Thermal Expansion of Buried Pipelines

Restraining Bowing of Pipelines

Appendix A: Properties of Pipe

Appendix B: Weights of Pipe Materials

Appendix C: Formulas for Pipe, Internal Fluid, and Insulation Weights

Index