2 WHY PIG? Government Regulations Decrease Corrosion Increase Efficiency /Decrease CorrosionIncrease EfficiencyDecrease Power CostsPre-Inspection CleaningOperational PiggingGauging Line Geometry
3 INFORMATION TO KNOW BEFORE PIGGING YOUR LINE Pipe DimensionsLine SizeLine IDPigs 1-5 % Larger Than Pipe ID2% OptimalLine LengthSelection Of Pig MaterialPipe MaterialInternal CoatingsWall ThicknessLine Pipe Grade May Determines ThicknessSelection of Pig MaterialIDOD
4 INFORMATION TO KNOW BEFORE PIGGING YOUR LINE Valve TypesSingle Biggest Cause Of Problems
5 INFORMATION TO KNOW BEFORE PIGGING YOUR LINE Bends1.5 D, 3D, 5D or GreaterMiter Bends
6 INFORMATION TO KNOW BEFORE PIGGING YOUR LINE Branched FittingsWyesTees (Barred or not)Tees > 50% of main diameter should be barredAt Least Three Diameters Of Straight Pipe Between Any Two Fittings
7 FLOW RATE Flow Rate Most Effective If Ran At Constant Speed Pig Velocity > 4ft/sec But <15ft/secIn General, the faster the pig travels the less efficient it becomes in being able to carry material in front of itApplicationSpeed (MPH)New Construction1-5On-Stream Gas2-8On-Stream Liquids1-8ILI Tools2-7
8 FLOW RATEPigs Are Driven Through The Line By Applying Pressure In The Direction Of Required Movement. A Pressure Differential Is Created Across The Pig, Resulting In Movement In The Direction Of The Pressure Drop.Once The Force Behind The Pig Becomes Greater Than The Opposing Frictional Force, The Pig Will Move In The Direction Of The Applied Force (Pressure).Break Out Point : When A Pig Begins To MoveGreater Than Pressure Required To Maintain Movement
11 Pigging Mediums Liquid Gas Incompressible Liquids Provide Maximum Control Over Pig Speed As Well As Lubricating SealsEnsure Seal Material Is Compatible With Propelling LiquidGasAs Gasses Are Compressible, The Amount Of Stored Energy Behind A Pig Propelled With Gas Is Far Greater Than That Of A Similar Pig Propelled With LiquidIncreased Wear On Sealing Discs
13 Pig Uses Batching Gauging Cleaning Barrier Between Dissimilar Fluids Soft Metal Plate90%-95% IDConfirms Integrity Of The Flow AreaCleaning
14 Pig Uses Magnetic Gel ILI Lift Ferrous Debris or Trip Pig Signals Mapping, Geometry Measurement, Metal Loss
15 CATAGORIES OF PIGS Foam Negotiate Short Radius Bends Various Densities 2-5 LB , 5-8 LB, 8-10 LBReduce In Diameter Up To 35%Numerous OptionsUsesDryingWipingCleaningProving
16 CATAGORIES OF PIGS Solid Cast Urethane Uses Hollow Shaft Can Handle 20% Reduction In Pipe IDCan Maneuver In Less Than 1.5D Radius BendsAdvantages: Non Brittle, Elastomeric Memory, Abrasion ResistantDisadvantages: Break Down In Higher Temps, Dissolves In Certain ChemicalsUsesSealingBatchingCleaning
17 CATAGORIES OF PIGS Solid Cast Urethane Durometer Types Of PolyurethanesCastable Elastomers: Prepolymer And A CuratorMDI (Methylenebisdiphenyl)More Expensive But More DurableTDI (Tolylenediisocyanate)Better Compression And Holds Up In Higher TemperatureDurometerMeasured By Shore Durometer or Rockwell TestThe Higher The Durometer The Harder The Urethane And The Better The Scraping Capability. The Softer The Durometer The Better The Sealing Capability.MDI : 70A-85A RangeTDI : 50A-90A Range
18 CATAGORIES OF PIGS Steel Mandrel Pig Most Aggressive Pigs Most VersitileDiscsSealing: < 1 Inch (High Sealing Low Scraping)Scraping: >1Inch (High Scraping Low Sealing)Slotted: Multi-Diameter LinesCupsScraper: Maximum Scraping - Reduce 15-20% Of DiameterConical: Maximum Sealing – Reduce 30-35% Of DiameterBrushesMounted To Ensure Full 360° Wall CoverageSize Of Bristle Has An Effect On The Size Of Anomaly It Can Clean
19 BrushesFlat Wire: Remove dirt, scale and large debris. Doesn’t clean pits well.Round Wire Brush: Ideal for pits. Easily handle thickness changes and 1.5D bends.Pencil Brush: Best for rust and loose debris. Rigid and doesn’t handle tight bends well.Wire Wheel Brush: Used for smaller diameters and not aggressive.Scrub Brush: Total wire foam pig. Good for finishing and polishing.
20 SOLUBLE PIGS Uses Options Advantages Proving Length Size Shape Water SolubleOil SolubleAdvantagesCannot Get StuckNo Cut Outs
22 PIG SIZING Pig Lengths Bullet Shaped Double Dish & Light Density Swab 2 Times Nominal DiameterSealing Length: 1.5 Times Nominal DiameterDouble Dish & Light Density Swab1.5 Times Nominal DiameterSolid CastApproximately 1.5 Times Nominal DiameterSteel Mandrel3” Longer Than Nominal Diameter (Small Pigs)6” Longer Than Nominal Diameter (Larger Pigs)
23 WHAT IS CLEAN? There Is No Industry Cleanliness Standard Remove Contaminates A Layer At A TimeCombination Of Pigs And Cleaning Solution
24 Dual Diameter Pigging Not to be confused with Multi-Diameter Solutions Butterfly or Petal DiscsPaddle PigWheel or Spring SuspensionTend to see higher wear in the smaller diameter line
25 Cleaning With Solvents Ran in conjunction with pigs to aid in cleaning the line.Designed to breakdown, suspend solids, and reduce surface tension to enhance cleaning programsSolvents are designed for:Penetrating solidsSuspending large volumes of solids in fluid columnsGetting deep into pitsCoat solids to keep them from sticking to each otherSolids come out in a slurry
26 PRE-RUN INSPECTION Pig must be in good condition Measure the sealing surface to ensure it is oversizedInspect the sealing surface for defectsUnrestrained diameter of the brushes must be measured to ensure contact with the pipeAlso inspect brushes for corrosion or breakage so they don’t fall apart in the line or damage fittingsDocumentation of these practices pre and post run can help maximize pig usage and decrease costly mistakes
28 PROGRESSIVE PIGGING Run Bare Foam Pig To Determine True Pipe Opening Continue To Run Bare Foam Pigs Until They Come Out CleanRun A Foam Criss Cross Coated Pig Just Larger Than The True Pipe OpeningRun A Bare Foam Pig Behind It To Improve Seal and Continue Criss Cross Pigs TravelContinue This Set Up Until A Criss Cross Pig Comes Out Re-UsableIncrease Pig Size ( ¼ ” to ½”) Until Full ID AttainedRun Two Full Size Pigs (Criss Cross or Wire Brush)Run A Swab Pig Behind It To Clear The LineFlush Line*Ideal Pig Speed Feet A Minute
29 PIGGING APPLICATIONS Sand Buildup Method 1 Method 2 Method 3 Run a large amount of light density swabsUsed when increased pigging volumes are not availableIt is very time consuming and not strong enough to push through the entire linePropelling medium may deposit more sand than pig removesMethod 2Using foam or steel pigs with bypass jetsThe bypass jets allow the propelling medium to bypass the pig creating turbulent flow keeping the sand suspendedThe bypass jets reduce the pig's speed by as much as 30%.If adequate volume is not available to propel a pig with bypass jets this method should not be usedThis method should not be used is where extreme deposits of 30% or more of sand existMethod 3Foam pigs and extreme high-volume propelling mediumThe pigs diameter is equal to the internal pipe diameter, less the largest amount of deposited sand per a cross-sectional view.For example, if we were pigging a 24" pipeline with a buildup of sand of 8", we would subtract 8" from 24" and use a 16" foam pigThe large volume propelling medium is going to bypass the pig causing turbulence to agitate the sand and keep it in suspensionIncrease pig diameter until nominal internal diameter of pipe is reached
30 PIGGING APPLICATIONS Butterfly Valves Butterfly valves cannot be pigged. It is not recommended to attempt pigging through a butterfly valve. If one is willing to attempt to pig a butterfly valve, they must accept full responsibility for any problems. *It is highly recommended to seek the aid of someone experienced with this type of special application pigging and to use a pressure recorder with 0 to150 psi and one-hour rotation capability. This should be mounted on the launching end of the line.
31 PIGGING APPLICATIONS Drying Pipelines This first run will remove anywhere from 85% to 95% of the water in the line.Most use criss-cross foam pigs because of flexibility, easy handling and low costRun a series of swabs to remove any moisture from the air in the line.From this point further the propellant should be dry.Brush foam pigs and swabs are now used to begin cleaning and removing the rust and millscale.These pigs are run at speeds of 7 to 10 feet per second and in alternating groups: first, three brush pigs, and then ten swabs.If receiving dust dry pigs, the pipeline is considered at 00 dew point.For negative dew points, pigging is continued.The last stage of pigging involves running a medium-density bare pig for a final wipe down and sweep of the line.
32 PIGGING PROBLEMS Over Cleaning When To Stop Pigging Pigging To Bare Metal Invites OxidationA Few Mils of Build Up Prevents Oxidation And Minimally Affects FlowWhen To Stop PiggingMonitor pressure drops when readings essentially level out.Time pig runs, if the volume is consistent pigging should stop when cleaning time has leveled out.When the number of seconds of receiving effluent is the same during subsequent pig runs, pigging should be stopped.Wirebrush pig runs should be limited to two or three.By running swabs nearing the end of pigging operation, they will both sweep the line of loose buildup as well as gauge the line’s cleanliness. When a swab is retrieved in good condition, pigging should stop.
48 WHAT IS PIG TRACKINGPig Tracking refers to monitoring the passage of a pig as it moves past prescribed and monitored points along the pipeline.Pig Locating refers to pinpointing a pig that has become stuck or lost in a given pipeline or pipe manifold system on land or at sea.
49 TYPES OF TRACKERSUnfortunately, carbon steel pipe acts as an ideal electromagnetic shield, which limits the possible methods of transmitting a signal through the pipe wall to a sensor. The common methods used to sense the passage of a pig or attempt to locate it are:Mechanical:have several drawbacks.invasive into the line, which makes them a potential environmental and safety hazard.subject to contamination by materials in the pipe, which can prevent them from operating correctly.subject to mechanical wear and damage, which will prevent them from operating properly.Intrusive Pig SignalsRadioactive:two main drawbacks.the radioactive nature of the transmitting device itself makes people extremely skittish in regards to using it.the transmitting distance is very limited which makes it primarily usable only when the “outside-the-pipe” sensor is directly attached to the pipe.Acoustic:systems generate an audible signal, which can be picked up by external sensors, but only when there is sufficient acoustic coupling between the transmitter and the wall of the pipe.This usually limits their use to lines filled with liquid, and as you might expect lines which do not operate in a high noise environment such as sub-sea lines.GeophonesMagnetic:Magnet equipped pigs operate well for tracking.They are not of any use in locating a stuck pig as it is practically impossible to locate them when they are not in motion.Non Intrusive Pig SignalsElectromagnetic:Utilize an electromagnetic transmitter, which is attached to, embedded in, or travels with the pipeline pig, and a receiver/wand that will pick up the signal from those transmitters at a distance allowing for significant ground cover.This signal is a low frequency signal that operates in the magnetic range of the electromagnetic spectrum, which allows the signal to penetrate the steel pipe wall to transmit a given distance through the ground.
50 PINPOINTING A STUCK PIG Pinpointing the location of the transmitter located in a stuck pig is a relatively simple operation.Move to the last leapfrogging location where you know the pig passed. At this point hold the wand horizontally and begin to slowly walk the line listening for the steady pulsing beep of the transmitter.Please note that you must be sure where the pipe is when you are attempting to walk the line.Lateral distance from the center of the pipe will greatly decrease the possibility of picking up the signal.Upon picking up the signal, continue walking towards the transmitter while watching the analog sweep meter.When the meter movement begins to decrease, move backward until you see the approximate maximum signal strength.Turn the wand vertical over the pipe.Slowly move the wand over the approximate area of maximum signal strength.The signal strength will increase and then fall to zero as well as the audible signal will disappear (in other words “NULL”) and then start to rise again.Move the wand back and forth until you center over the “NULL”.You should now be standing directly over the transmitter.
51 REMOVING STUCK PIGS Type 1: Options: Loss Of Seal →Propelling Medium Bypassing PigExcessive Wear On A long Pig RunDual Diameter LineAbrasive Line ConditionsTorn Pig Due To Partially Closed Valves Or DebrisOptions:Increase Pigging VolumeAmount Not Bypassing May Be Enough To Propel The PigRemove Pressure & VolumeWait 15 Min For Pig To Regain ShapeRun A Line-Size Swab2LB Density Pig Will Try To Bypass Stuck Pig & Reseal 1st PigReverse Flow DirectionSend Pig Back A Few Feet Then Send The Original Direction (Bidirectional Only)Cut Out
52 REMOVING STUCK PIGS Type 2: Obstructed Options: Excessive Debris Build-UpPartially Closed ValvesTools, Animals, Etc.Options:Increase Pigging PressureIncreased Force To Push The ObstructionIncrease / Decrease Pigging PressureQuick On-&-Off Fashion (Kick In The Rear)Works Well In Small ID Fittings, Tight Bend Ells & ValvesRemove Pressure & VolumeWait 15 Min For Pig To Regain ShapeReverse Flow DirectionSend Pig Back A Few Feet Then Send The Original Direction (Bidirectional Only)Cut Out
53 Any Questions Or Comments? Any Further Information Or Assistance Can Be Provided.Just Contact Us By Or Phone.The Pigging Guide CD-ROM Has Pigs Available As Well As Technical Information.Anything Not Seen In The Catalog Can Be Made