Gerhard Hiltscher, Wolfgang Mhlthaler, Jrg Smits

Industrial Pigging Technology

Fundamentals, Components, Applications

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G. Hiltscher, W. Mhlthaler, J. Smits

Industrial Pigging Technology

Gerhard Hiltscher, Wolfgang Mhlthaler, Jrg Smits

Industrial Pigging Technology

Fundamentals, Components, Applications

Editor

Prof. Dr.-Ing. Gerhard HiltscherUniversity of Applied SciencesMechanical Engineering Department68163 MannheimGermany

Dipl.-Ing. Wolfgang MhlthalerK. Mhlthaler IndustrieberatungsserviceMolchtechnik und TanklagerbauRegerstr. 1369502 HemsbachGermany

Dipl.-Ing. Jrg SmitsBASF AktiengesellschaftWLF/EA-L44367056 LudwigshafenGermany

& This book was carefully produced. Never-theless, authors and publisher do notwarrant the information contained thereinto be free of errors. Readers are advisedto keep in mind that statements, data,illustrations, procedural details or otheritems may inadvertently be inaccurate.

Library of Congress Card No.applied for

British LibraryCataloguing-in-PublicationDataAcatalogue record for this book is availablefrom theBritish Library.

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2003 WILEY-VCH Verlag GmbH & Co.KGaA, Weinheim

Printed on acid-free paper.

All rights reserved (including those of trans-lation in other languages). No part of thisbook may be reproduced in any form byphotoprinting, microfilm, or any othermeans nor transmitted or translated into amachine language without written permis-sion from the publisher. Registered names,trademarks, etc. used in this book, evenwhen not specifically marked as such, arenot to be considered unprotected by law.

Printed in the Federal Republic of GermanyComposition Khn & Weyh, FreiburgPrinting Strauss Offsetdruck, MrlenbachBookbinding Grobuchbinderei J. SchfferGmbH & Co. KG, GrnstadtISBN 3-527-30635-8

I Fundamental Principles of Pigging Technology 1

1 Introduction to Pigging Technology 31.1 Historical Development and Definition 31.2 Fields of Application of Pigging Technology 6

2 Pigging Units and Pigging Systems 92.1 Definitions 92.2 Selection and Design Criteria 122.3 Pigging Units 132.3.1 Pigging Units without Branches 132.3.2 Pigging Units with Branches 142.3.3 Pigging Units with Switches 142.4 Pigging Systems 152.4.1 Sequence Tables 152.4.2 One-Pig Systems 172.4.3 Two-Pig Systems 18

II Components 21

3 Pigs 233.1 Pigs for Industrial Pigging Units 233.1.1 Function 233.1.2 Fields of Application 233.2 Materials Selection 243.2.1 Pig Materials 253.2.2 Tests for the Selection of Pig Materials 253.2.3 Shear Strength of the Pig Material 323.2.4 Deformation of a Solid Cast Pig under Pressure 343.3 Pig Designs 363.3.1 One-Piece Pigs 373.3.2 Multicomponent Pigs 413.3.3 Special Pigs 43

V

List of Contents

3.4 Fabrication of Pigs 443.5 Quality Assurance 45

4 Valves 494.1 Function of Piggable Valves 494.2 Classification of Piggable Valves 504.3 Examples of Standard Valves 504.3.1 Stations 504.3.2 Branches 544.3.3 Pig Traps 584.3.4 Switches 594.4 Examples of Commercially Available Special Valves 624.4.1 Crossing of Two Piggable Pipes 634.4.2 Manifolds 644.4.3 Piggable Loading Facilities 674.4.4 Drum-loading Valves 684.5 Pressure Drop in Piggable Valves 704.6 Stress on Pig Traps 71

5 Pipework 755.1 Requirements for Piggable Pipes 755.2 Materials for Piggable Pipes 765.3 Piping Elements 785.3.1 Pipes 785.3.2 Pipe Bends 835.3.3 Tees 855.4 Pipe Joints 865.4.1 Flange Connections 865.4.2 Welded Pipe Joints 895.5 Example of a Pipe Specification 945.6 Construction of Piggable Pipes 955.7 Piggable Hoses 96

6 Additional Equipment 996.1 Pressure-Relief Vessel 996.2 Propellant Tank 1006.3 Filters 1026.4 Pumps 102

7 Propellants 1057.1 Gaseous Propellants 1057.1.1 Speed Behavior of Gas-Driven Pigs 1077.1.2 Remedial Actions 1097.2 Liquid Propellants 110

List of ContentsVI

VII

7.2.1 Properties of Liquid Propellants 1107.2.2 Dimensioning of Liquid-Propelled Pigging Units 111

8 Control System 1138.1 Components of the Control System 1138.1.1 Sensors 1148.1.2 Permanent Magnets and Magnet Sensors 1168.1.3 Actuators 1198.2 Operating Modes of the Sequence Control 1208.2.1 Manual Operation 1208.2.2 Enhanced Manual Operation 1208.2.3 Touch-Controlled Operation 1208.2.4 Automatic Operation 1218.3 Examples of Sequence Control 1218.3.1 Sequence Control of a One-Pig System 1218.3.2 Sequence Control of a Two-Pig-System 1288.3.3 Sequence Control of a Cleaning Procedure 134

III Applications 139

9 Decision Criteria for Pigging 1419.1 General Criteria 1419.1.1 Product Infrastructure Technology 1419.1.2 Physical and Chemical Properties of the Products 1429.2 Economic Criteria 1439.2.1 Long Pipeline without Cleaning Procedures 1449.2.2 Omission of Tracing 1469.2.3 Multiproduct Pipe 1489.2.4 Evaluation of the Examples 1509.3 Quality Criteria 1519.4 Environmental Criteria 151

10 Cleaning Degree after Pigging 15310.1 Qualitative Classification 15310.2 Precalculation for the Cleaning Degree 15310.3 Concept 15510.3.1 Inner Surface Roughness of Pipes and Valves 15510.3.2 Welding Seams 15710.3.3 Flange Connections 15810.3.4 Dead Spaces 15910.3.5 Residual Film of the Pigged Pipe 16110.4 Exemplary Calculation for Residual Concentration in a Plant 16610.5 Errors 169

List of Contents

VIII

11 Pig Wear 17311.1 Fundamentals 17311.2 Wear Characteristics and Service Life of Pigs 17611.3 Minimum Permissible Pig Diameter 17711.4 Wear Inspection 17911.5 Operating Mode 180

12 Medium-Specific Characteristics 18112.1 Introduction to Fluid Dynamics 18112.2 Classification of Fluids with Examples 18212.2.1 Viscosity Curves 18312.2.2 Principles of Calculation 18512.3 Examples and Applications 18612.3.1 Newtonian Behavior 18612.3.2 Non-Newtonian Behavior 187

13 Checks before Start-up 18913.1 Checking Equipment 18913.1.1 Piggable Pipes 18913.1.2 Pigs 19013.1.3 Additional Equipment 19013.2 Function Checks 19013.2.1 Test Pigging 19013.2.2 Concentration Measurement 19213.2.3 Test Pigging: a Practical Example 192

14 Experiences with Pigging Units 19714.1 Experiences before Start-up 19714.1.1 Decision-Making 19714.1.2 Planning 19814.1.3 Procurement 19814.1.4 Installation 19914.2 Experiences after Start-up 20014.2.1 Equipment Defects 20014.2.2 Malfunctions during Operation 20114.2.3 Documentation of Rare Events 203

15 Applications in the Chemical Industry 20515.1 Polymer Dispersions 20515.1.1 Production Plant 20515.1.2 Product Properties 20515.1.3 Purpose of the Pigging Unit 20615.1.4 Technical Data of the Pigging Lines 20615.1.5 Description of the Function 20815.2 UreaFormaldehyde Resins 209

List of Contents

IX

15.2.1 Production Plant 20915.2.2 Product Properties 20915.2.3 Purpose of Pigging 21015.2.4 Technical Data of the Pigging Lines 21015.2.5 Description of the Function 21115.3 Dispersion Adhesives 21315.3.1 Production Plant 21315.3.2 Product Properties 21415.3.3 Purpose of Pigging 21415.3.4 Technical Data of the Pigging Lines 21415.3.5 Description of the Function 21515.4 Fragrances 21615.4.1 Production Plant 21615.4.2 Product Properties 21715.4.3 Purpose of Pigging 21715.4.4 Technical Data of the Pigging Line 21715.4.5 Description of the Function 21915.5 Raw Materials 22015.5.1 Production Plant 22015.5.2 Product Properties 22015.5.3 Purpose of Pigging 22115.5.4 Technical Data of the Pigging Line 22115.5.5 Description of the Function 222

16 Pigging Units for Sterile Technology 22516.1 Characteristics of Sterile Technology 22516.2 Terms in Hygienic Design 22716.3 Materials for Sterile Technology 22916.4 Elements of Sterile Pigging Technology 23016.4.1 Pigs 23016.4.2 Pig Cleaning Stations 23116.4.3 Pipelines 23216.4.4 Pipe Joints 23216.5 Example 234

17 Pipeline Pigging 23717.1 Distinction from Industrial Pigging Units 23717.2 Pipes and Fittings 24017.2.1 Pipes 24017.2.2 Tolerances 24117.2.3 Fittings 24317.3 Function of Pigs in Pipelines 24417.4 Pigs for Pipelines 24717.4.1 Mechanical Pigs 24717.4.2 Smart Pigs 249

List of Contents

X

17.4.3 Gel Pigs 25517.5 Pig Launchers and Receivers 255

18 Pigging of Pneumatic Conveying Lines for Bulk Materials 25918.1 Pneumatic Conveying of Bulk Materials 25918.2 Structure of Pneumatic Conveying Systems 26018.2.1 Basic Structure of Pneumatic Conveying Systems 26018.2.2 Structure of a Pigging System for Bulk Conveying Lines 26518.3 Cleaning of Pneumatic Conveying Lines 26718.3.1 Purging 26718.3.2 Cleaning Pellets 26718.3.3 Wet Cleaning 26718.4 Pigs for Pneumatic Conveying Lines 26818.4.1 Soft Pigs 26818.4.2 Turbo Pig 26918.4.3 Notch Pigs 27018.4.4 Jet Pigs 271

IV Law and Regulation 273

19 Legal Requirements 27519.1 Laws, Regulations, and Guidelines 27519.2 Required Permissions and Examinations 27619.2.1 Pressure Hazard 27619.2.2 Ground Water Contamination 27719.2.3 Explosion-Hazard Areas 278

20 Safety and Occupation Health 27920.1 Kinetic Energy of the Pig 27920.2 Energy of the Propellant 28020.3 Definition of Explosion Hazard Terms 28320.3.1 Ignitibility and Ignition Temperature 28320.3.2 Explosion Protection of Environment and Off-Gas 28420.3.3 Protection against Electrostatic Charging 28520.3.4 Accident Prevention in Explosion-Hazard Plants 28520.4 Ignition Hazard with Compressed Air as Propellant 28620.4.1 Explosive Mixture Properties 28620.4.2 Calculation of the Explosive Composition and Volumetric Concentration in

a Pipeline 28720.4.3 Electrostatic Charge 29120.4.4 Accident Prevention for Equipment 29220.4.5 Remedial Measures for Hazardous Operating Conditions 29320.5 Evaluation of Operation Safety and Explosion Hazard Classification 293

List of Contents

XI

V Appendix 295References 297List of Chemical Resistances 301Description of Material Codes 302Properties of Solvents 324Buyers Guide 325Suppliers Names and Adresses 327Index 329

List of Contents

Symbol Designation Unit

A area, cross-sectional area m2

a distance ma sound velocity m/sB magnetic induction T = Wb/m2

b width m, mmc velocity m/sC concentration %, ppmCR residual conc. in the following product %, ppmCv volume concentration %, ppmCm molar concentration %, ppmD shear rate, velocity gradient s1

D, d diameter m, mmE modulus of elasticity in tension N/mm2

E kinetic energy JF force Nf frequency Hzf deflection mmG modulus of elasticity in shear N/mm2

h height mmH magnetic field intensity A/mI moment of inertia mm4

K constant K modulus of elasticity in compression N/mm2

L*/d pig: sealing length/diameter ratio L, l length m, mmL/d pig: total length/diameter ratio M molar mass kg/kmolm mass kgMb bending moment Nmn number Ol largest possible oversize mm

XIII

Notation

Industrial Pigging TechnologyList of ContentsNotationPrefaceI Fundamental Principles of Pigging Technology1 Introduction to Pigging Technology1.1 Historical Development and Definition1.2 Fields of Application of Pigging Technology

2 Pigging Units and Pigging Systems2.1 Definitions2.2 Selection and Design Criteria2.3 Pigging Units2.3.1 Pigging Units without Branches2.3.2 Pigging Units with Branches2.3.3 Pigging Units with Switches

2.4 Pigging Systems2.4.1 Sequence Tables2.4.2 One-Pig Systems2.4.3 Two-Pig Systems

II Components3 Pigs3.1 Pigs for Industrial Pigging Units3.1.1 Function3.1.2 Fields of Application

3.2 Materials Selection3.2.1 Pig Materials3.2.2 Tests for the Selection of Pig Materials3.2.3 Shear Strength of the Pig Material3.2.4 Deformation of a Solid Cast Pig under Pressure

3.3 Pig Designs3.3.1 One-Piece Pigs3.3.2 Multicomponent Pigs3.3.3 Special Pigs

3.4 Fabrication of Pigs3.5 Quality Assurance

4 Valves4.1 Function of Piggable Valves4.2 Classification of Piggable Valves4.3 Examples of Standard Valves4.3.1 Stations4.3.2 Branches4.3.3 Pig Traps4.3.4 Switches

4.4 Examples of Commercially Available Special Valves4.4.1 Crossing of Two Piggable Pipes4.4.2 Manifolds4.4.3 Piggable Loading Facilities4.4.4 Drum-loading Valves

4.5 Pressure Drop in Piggable Valves4.6 Stress on Pig Traps

5 Pipework5.1 Requirements for Piggable Pipes5.2 Materials for Piggable Pipes5.3 Piping Elements5.3.1 Pipes5.3.2 Pipe Bends5.3.3 Tees

5.4 Pipe Joints5.4.1 Flange Connections5.4.2 Welded Pipe Joints

5.5 Example of a Pipe Specification5.6 Construction of Piggable Pipes5.7 Piggable Hoses

6 Additional Equipment6.1 Pressure-Relief Vessel6.2 Propellant Tank6.3 Filters6.4 Pumps

7 Propellants7.1 Gaseous Propellants7.1.1 Speed Behavior of Gas-Driven Pigs7.1.2 Remedial Actions

7.2 Liquid Propellants7.2.1 Properties of Liquid Propellants7.2.2 Dimensioning of Liquid-Propelled Pigging Units

8 Control System8.1 Components of the Control System8.1.1 Sensors8.1.2 Permanent Magnets and Magnet Sensors8.1.3 Actuators

8.2 Operating Modes of the Sequence Control8.2.1 Manual Operation8.2.2 Enhanced Manual Operation8.2.3 Touch-Controlled Operation8.2.4 Automatic Operation

8.3 Examples of Sequence Control8.3.1 Sequence Control of a One-Pig System8.3.2 Sequence Control of a Two-Pig-System8.3.3 Sequence Control of a Cleaning Procedure

III Applications9 Decision Criteria for Pigging9.1 General Criteria9.1.1 Product Infrastructure Technology9.1.2 Physical and Chemical Properties of the Products

9.2 Economic Criteria9.2.1 Long Pipeline without Cleaning Procedures9.2.2 Omission of Tracing9.2.3 Multiproduct Pipe9.2.4 Evaluation of the Examples

9.3 Quality Criteria9.4 Environmental Criteria

10 Cleaning Degree after Pigging10.1 Qualitative Classification10.2 Precalculation for the Cleaning Degree10.3 Concept10.3.1 Inner Surface Roughness of Pipes and Valves10.3.2 Welding Seams10.3.3 Flange Connections10.3.4 Dead Spaces10.3.5 Residual Film of the Pigged Pipe

10.4 Exemplary Calculation for Residual Concentration in a Plant10.5 Errors

11 Pig Wear11.1 Fundamentals11.2 Wear Characteristics and Service Life of Pigs11.3 Minimum Permissible Pig Diameter11.4 Wear Inspection11.5 Operating Mode

12 Medium-Specific Characteristics12.1 Introduction to Fluid Dynamics12.2 Classification of Fluids with Examples12.2.1 Viscosity Curves12.2.2 Principles of Calculation

12.3 Examples and Applications12.3.1 Newtonian Behavior12.3.2 Non-Newtonian Behavior

13 Checks before Start-up13.1 Checking Equipment13.1.1 Piggable Pipes13.1.2 Pigs13.1.3 Additional Equipment

13.2 Function Checks13.2.1 Test Pigging13.2.2 Concentration Measurement13.2.3 Test Pigging: a Practical Example

14 Experiences with Pigging Units14.1 Experiences before Start-up14.1.1 Decision-Making14.1.2 Planning14.1.3 Procurement14.1.4 Installation

14.2 Experiences after Start-up14.2.1 Equipment Defects14.2.2 Malfunctions during Operation14.2.3 Documentation of Rare Events

15 Applications in the Chemical Industry15.1 Polymer Dispersions15.1.1 Production Plant15.1.2 Product Properties15.1.3 Purpose of the Pigging Unit15.1.4 Technical Data of the Pigging Lines15.1.5 Description of the Function

15.2 UreaFormaldehyde Resins15.2.1 Production Plant15.2.2 Product Properties15.2.3 Purpose of Pigging15.2.4 Technical Data of the Pigging Lines15.2.5 Description of the Function

15.3 Dispersion Adhesives15.3.1 Production Plant15.3.2 Product Properties15.3.3 Purpose of Pigging15.3.4 Technical Data of the Pigging Lines15.3.5 Description of the Function

15.4 Fragrances15.4.1 Production Plant15.4.2 Product Properties15.4.3 Purpose of Pigging15.4.4 Technical Data of the Pigging Line15.4.5 Description of the Function

15.5 Raw Materials15.5.1 Production Plant15.5.2 Product Properties15.5.3 Purpose of Pigging15.5.4 Technical Data of the Pigging Line15.5.5 Description of the Function

16 Pigging Units for Sterile Technology16.1 Characteristics of Sterile Technology16.2 Terms in Hygienic Design16.3 Materials for Sterile Technology16.4 Elements of Sterile Pigging Technology16.4.1 Pigs16.4.2 Pig Cleaning Stations16.4.3 Pipelines16.4.4 Pipe Joints

16.5 Example

17 Pipeline Pigging17.1 Distinction from Industrial Pigging Units17.2 Pipes and Fittings17.2.1 Pipes17.2.2 Tolerances17.2.3 Fittings

17.3 Function of Pigs in Pipelines17.4 Pigs for Pipelines17.4.1 Mechanical Pigs17.4.2 Smart Pigs17.4.3 Gel Pigs

17.5 Pig Launchers and Receivers

18 Pigging of Pneumatic Conveying Lines for Bulk Materials18.1 Pneumatic Conveying of Bulk Materials18.2 Structure of Pneumatic Conveying Systems18.2.1 Basic Structure of Pneumatic Conveying Systems18.2.2 Structure of a Pigging System for Bulk Conveying Lines

18.3 Cleaning of Pneumatic Conveying Lines18.3.1 Purging18.3.2 Cleaning Pellets18.3.3 Wet Cleaning

18.4 Pigs for Pneumatic Conveying Lines18.4.1 Soft Pigs18.4.2 Turbo Pig18.4.3 Notch Pigs18.4.4 Jet Pigs

IV Law and Regulation19 Legal Requirements19.1 Laws, Regulations, and Guidelines19.2 Required Permissions and Examinations19.2.1 Pressure Hazard19.2.2 Ground Water Contamination19.2.3 Explosion-Hazard Areas

20 Safety and Occupation Health20.1 Kinetic Energy of the Pig20.2 Energy of the Propellant20.3 Definition of Explosion Hazard Terms20.3.1 Ignitibility and Ignition Temperature20.3.2 Explosion Protection of Environment and Off-Gas20.3.3 Protection against Electrostatic Charging20.3.4 Accident Prevention in Explosion-Hazard Plants

20.4 Ignition Hazard with Compressed Air as Propellant20.4.1 Explosive Mixture Properties20.4.2 Calculation of the Explosive Composition and Volumetric Concentration in a Pipeline20.4.3 Electrostatic Charge20.4.4 Accident Prevention for Equipment20.4.5 Remedial Measures for Hazardous Operating Conditions

20.5 Evaluation of Operation Safety and Explosion Hazard Classification

V AppendixReferencesList of Chemical ResistancesDescription of Material CodesProperties of SolventsBuyers GuideSupplier's Names and Addresses

Index