chapter 6 - pipeline pigs

8/12/2019 Chapter 6 - Pipeline Pigs

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Canadian Pump & Packing Co. Ltd.9804 54 Avenue, Edmonton AB T6E 0A9

Phone: 780-438-0483 Fax: 780-435-5143 Toll-Free: 1-800-871-4160www.cdnpumpandpack.ca

PIGGING

INFORMATION


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WHAT IS A PIG?

A pig is an object that is sent through a pipeline to clean and maintain it. A typical pig isnormally twice as long as its diameter. Pigs are made up of various types of foam,rubber, urethane, Teflon or metal. They can have many styles and combinations ofattachments designed to help push or pull them through the line. There are as manydifferent styles, sizes and combinations of pigs as there are products running throughpipelines.

WHY TO PIG?

With rising costs and inflation, we need to conserve as much energy and productiontime as possible. With the push to reduce energy use, which heavy industry bears thebrunt of, pigging is the fastest, most economical way to maintain internal pipe integrity.

The purpose of pigging is to wipe, sweep, scrape, scale or dry a pipeline. Wiping theline means to clear out one product so that the pipe may be used for another.Sweeping means the removal of loose debris or dirt in the line. Scraping means toremove the hard deposits that have built up around the inside walls of the pipe, andreturn the flow within the pipe to normal. Scaling is used when a chemical has been

sent through to clean deposits from the sides of the pipe, and the chemical must now beremoved so that normal production may resume. Drying means to remove any dirt ordust, which may contain moisture, to prevent corrosion from occurring in the pipe.

The most common method of pigging requires a different medium to propel the pig thanthe one that normally runs through the line. Usually, water, air or nitrogen is used topush the pigs because they are easily cleaned out of the line when done. Pigging a lineclean without interrupting service is possible, however. This is called the on-streammethod. A pig is inserted into a line, and is propelled forward by the force of the normalflow. This is the best method to use where product purity is concerned.


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HOW TO PIG

A pig launcher is the portable unit that can be easily attached to a pipeline to send a pigthrough the line. A typical launcher is a piece of pipe one size larger and twice as longas the pig, with an end that is flanged, hinged or union closed.

A pig launcher is probably the most important tool to use with a pig. However, othermethods of launching must be sought when the expense of a launcher would rule outthe benefits of a pigging job. Examples of this would be; when the location is remoteand there is no accessible source of launching medium, or when a launcher cannoteasily be attached onto the pipe.

Other methods of launching are: Lubricating the pig, and then using a blunt ended rod to manually push it

into the line. This can be done either with or without some form of aswage (funnel)

Twisting the pig into the line without the aid of a lubricant will work up to a4 pig

Split the pipe about three/fourths the length of the pig. Then lubricate thepig, insert it and push it beyond the split. Pull the split back together andweld.

Adding glycol/water mixture in front of the pig is common, especially in the winter. Thiswill melt the ice in the line, reduce the friction on the front of the pig and aid in thecleaning of the pipe. Once the pig is in the line, replace the cap or pipe end and start topressure-up. The pig will start to move at different pressures, depending on whichpressure medium is being used.

If using nitrogen, air or gas, once the pressure has built up to half of the normaloperating pressure the pig should start to move. The speed the pig is moving at and thedistance it travels will reduce the pressure per volume behind the pig. Should the pigstop, before attempting to unblock it, simply allow the pressure behind the pig to buildback up to normal operating pressure; it should start to move again. Most pressuresystems, whether permanent or portable, work at 100 psi.

If water or another liquid is being used, a quick spurt should get the pig moving once theliquid level is halfway to three-quarters of the way up the back of the pig. Waterpressure will propel the pig through the line with the speed adjusted by the flow at the

inlet valve.


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The usual rate of speed for cleaning is about 60 feet per minute, but speeds of twicethis rate have been used on straight pipelines. Slower speeds are necessary, whenpassing through tees, crosses, undersized valves or swedging into smaller pipe sizes,to prevent pressure surges. Complete cleaning usually requires two or more passes ofthe pig; however, running two or more pigs through at the same time, has the same

effect but saves money and energy.

A pig receiver is the portable unit that can be easily attached to a pipeline to catch thepig at the far end. There are two main types of receivers. The most common is abasket style, which catches the pig and releases the pressure and any debris. Theother is a solid style. It consists of a piece of pipe one size larger and twice as long asthe pig. It has a blockage in it to stop the pig along with a valve to release pressure andwhatever the pig cleaned out of the line. For environmental or hazardous lines, a solidpig receiver with a debris suppressor containing a filter bag will be required, togetherwith a legal means of disposal.

A pig receiver, while not as important as a launcher, should be considered. Whenallowed, the easiest method is letting the pig exit the pipe and picking it up from theground. Remember, the pig will become a projectile when propelled by a liquid; the pigwill fall with the flow. When a receiver is required, a bypass route is also needed so thatthe propelling medium can continue unhindered, once the pig has been caught.

Always remember to consult a specialist before pigging your lines. With the differenttypes of lines, pipe, valves and conditions in every field, pigs that work in one field maynot work well in another.


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CLEARING BLOCKED LINES

Occasionally, during pigging operations, pigs will become blocked. Should this happen,there are remedies other than digging up the line.

There are two main types of blocked pigs:1. Non-bypass pigs2. Bypass (filming pigs)

For all pigs, the following steps are recommended:1. Increasing volume and pressure2. Releasing pressure by opening a discharge valve and dropping pressure to

nothing, then reapplying pressure.

3. Releasing pressure and volume by opening a discharge valve, allowing fluidto drain and dropping the pressure to nothing; then flooding the line causing awater hammer. This should propel the pig through the tight spot.

4. Releasing pressure and volume, and then leaving the system down for 30minutes to one hour. With normal pigging applications, pressure applied tothe rear of the pig causes a friction drag on the front of the pig, whichtherefore compresses the pig. By allowing a rest, the pig can return to itsprevious size and normal pigging procedures should release the pig without asignificant increase in pressure.

5. Applying pressure in the reverse direction back up to the pig. Usually there isno need to back the pig up more than a few feet, normal pigging procedures

can then resume.6. On certain types of lines (chiefly water), flowing a strong concentration ofchlorine past the pig can dissolve and break down the cell structure. Thisshould be the last resort!

Note: For bypass (filming) pigs only; insert a pipe swab (YBS), and push it up to theblocked pig to create a positive seal. Pressuring up normally should then release thepig.


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COMMON QUESTIONS FOR PIGGING NEEDS

Pipe Size O.D. and/or I.D.Wall Thickness O.D. and/or I.D.Schedule of Pipe

Reducers? Yes No From To

Bends Ts

90s Dual Diameter Pipe? Yes No 45s If Yes, from what sizes?

Type of pipe? Steel Insitu Coated Other Fiber Glass Lined

PVC

HDPE LinedPressure: PSI/LB KPA

What is it pushing?

Contents: H2S% SW Gas Condensate Water CO2 OilInert Slag Hydraulic Wax Other Fluid

Type of Pigs Used?

Other Required Information:

Is there a regular pigging program in place currently?Are you changing the contents of the line?Are you coating the wall of the line?Is there a build up in the line?Type of build up?Type of launching/receiving equipment?Manufacturer name of launching/receiving equipment?

Argus Barber Masterflo Other

What type of problems are you experiencing with your current pigging application?


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COMMON

PIPELINE PIGS


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POLLY PIGS

Polly Pigs are internal pipe cleaners made of flexible foam with a variety of urethane coatingand abrasives. They have the greatest versatility, lowest cost, and are the most flexible and canbe the most durable of all types of pipeline pigs.

The standard pig is always slightly oversized to cause a friction drag which is the resistance tothe pressure being applied to the rear of the pig.

When Polly Pigs are put through a line, there is friction drag on the front and pressure is applied

to the rear. When these two forces meet in the middle they make the pig shorter and direct theforces to the outside wall of the pipe. This causes a high velocity bypass from the rear to thefront past the pig, resulting in a sliding seal, helping to cut loose deposits and flushing ahead ofthe pig.

There are three basic types of Polly Pigs that are available in different densities:1. Dryers2. Wipers3. Scrapers

The harder the density of the pig the less flexible and compressible they become. Urethanecoatings and wire brushes add strength and durability to Polly Pigs but also cause the pigs to

become less flexible and compressible.

New pipelines should not be put into service before one or more drying Polly Pigs have beenrun through the line to clear out any construction and other debris that may have been leftbehind.


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FUNCTIONS OF THE VARIOUS TYPES OF POLLY PIGS

To follow are the most commonly used Polly pigs:

YBS- Yellow Bare Swab 2lb/cuft 32.0 kg/m

Mainly Used for Light Drying and WipingUp to 1 mileThese pigs can also be used:1. Where daily pressures are low and there is rapid build-up in

your line.2. To clear blocked lines when a bypass pig gets stuck.

3. When line conditions do not allow a heavier density foam pig.Remember these will not do a good cleaning.4. When the entrance into a larger line is through a muchsmaller line. Example: 12" line with a 6" opening.

RBS- Red Bare Squeegee 5 lb/cu.ft. 80.1 kg/mMainly Used for Regular Dryingup to 10 miles (16 km)

Best used for drying any smooth interior pipelines and for removal ofsoft build-ups in any type of pipe.Can be substituted for an RCC when pigging multiple lines and on

systems where existing pressure and volumes are questionable. Canalso be used where low pressures prevail for mild cleaning, gauging

the I.D. of a scaled line, or as a prover pig.

RCC - Red Criss Cross - 5 lb/cu.ft 80.1 kg/mMainly Used for regular Wipingup to 10 milesGood for paraffin removal. Also, good for wiping most pipelines witha soft build-up. Best used in minimum pressure lines with a largequantity of short radius 90bends, tees and valves. Also good

where piping conditions, volumes and pressures are questionable.Should be used instead of RCC-WB pigs when using fibreglass, PVCor epoxy lined pipe.

RCC-WB- Red Criss Cross Wire Brush - 5 lb/cu.ft. 80.1 kg/mMainly Used for Regular scrapingup to 10 miles (16 km) and

scale removal.Excellent for removal of large amounts of paraffin build-up.

Good for hard scratching on bare walls of steel pipe.

FULLY COATED- 5 lb/cu.ft 80.1 kg/mFor wiping lines that contain up to 12% H2S, CO2or other

chemicals that attack regular foam.


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FUNCTIONS OF THE VARIOUS TYPES OF POLLY PIGS Cont.

MESH PIGSMade for added Strength

BI-DIRECTIONALThese pigs were made when two directions are to be traversedby the pig without leaving the pipe. Not recommended for normally

cleaning the line.

DOUBLE NOSE BI-DIRECTIONALThis pig has the same function as a Bi-directional but willusually move through the line at approximately half the speedof a double dish due to no flat surfaces for the pressure to push.

PIGS WITH PULLING ROPESMade for ease of pulling pigs out of lines.

PIGS WITH TRACKING CAVITIESMade for tracking or finding when lost.

Standard sizes of Polly pigs available:

2", 2-1/4", 2-1/2" 6", 6-1/4", 6-1/2"3", 3-1/4", 3-1/2" 8", 8-1/4", 8-1/2"4", 4-1/4", 4-1/2" Up to 60"

Canadian Pump & Packing will make most pigs in any size according to yourspecifications. The normal length of a Polly Pig is approximately twice the diameter.Canadian Pump & Packing will also make lengths either shorter or longer, according toyour specifications.

This list is just a general overall view of the most common Polly Pigs. There arenumerous other styles & densities of Polly pigs not listed (as they are too many to

mention and are made for special conditions) but are readily available. Remember toalways consult a specialist for your specific conditions.


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PIG BALLS

Excellent for scraping and sweeping of lines

Most Commonly Available in:

Natural Rubber, Neoprene or Buna*Made in sizes of 3/4" - 6"*Black, Colored or Numbered available*Most Numbered Pig balls have the numbersmolded, not burnt, into them for longer life ofnumbers

Urethane

*Available in sizes of 3/4" - 12"using 1/4" increments*For use in sour service applications

Foam*High Density Foam*Solid Foam - white or colored*Fully Coated Urethane (FC)*Red Criss Crossed (RCC)*Wire brush & Urethane (RCC-WB)*Made in sizes 1/2"up to 12"

RCC-WB RCC Fully Coated Foam

Canadian Pump & Packing Co. Ltd. can supply fully coated foam balls in size increments assmall as 1/16". Example: 2-1/16, 2-1/8, etc.

Inflatable BallsSpecialty balls available upon request in a variety of sizes

Other Specialty Compounds may also be available


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BULLET PIGS

Available in:

Buna or Neoprene

Hollow or Filled

Use in place of/or with balls

PUMP OUT PIGS - SOLID URETHANEForPumping Out Bottom Hole Pumps

Available in:

Sizes from 1/2" up to 6" diameter

Length is twice to diameter of the pig

Numerous colors

Size A B C - Hollow C - Filled

2" 2.02" 2.95" 1.86" 1.03"

3" 3" 3.5" 2.76" 1.54"

4" 4.25" 4.31" N/A 1.75"


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MAXI DISC PIGS

Maxi-Disc pipeline pigs are one piece high quality urethane constructed pigs with nometal parts designed for maximum efficiency. No assembly required.

Maxi-Discs will not by-pass fluids, but will expand against the pipeline wall forming anefficient seal as the pressure differential across the pig increases.

They are available in Hollow or Solid Core. Use Hollow Core Maxi-Discs only in casesof low pressures.Available in 60 Durometer, 70 Durometer and 80 Durometer (+/- 5 Durometer)Also available with only 3 discs (short)

Sizes available from 2" - 16"

SIZE A B C D WEIGHT3 DISCSHORT

250mm

2.16555mm

1.15029mm

4.25108mm

4.90124mm

.75 lb..340 kg

N/A

380mm

3.1981mm

1.9449mm

6.25159mm

7.00178mm

1 lb..453 kg

5.18

4100mm

4.25108mm

2.2557mm

8.50216mm

9.50241mm

2 lb..907 kg

7.19

6150mm

6.25159mm

3.0076mm

11.25286mm

12.50317mm

5lb.2.26 kg

10

8

200mm

8.50

216mm

4.50

114mm

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387mm

16.50

419mm

16lb.

7.25 kg

12.75

10250mm

10.50267mm

5.50140mm

18.00457mm

19.50495mm

20lb.9 kg

N/A

12300mm

12.50317mm

6.50165mm

20.00508mm

21.50546mm

42 lb.19 kg

N/A


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MAXI CUP PIGS

Maxi-Cups made for batching and general purpose cleaning.

They are no maintenance, highly resilient, provide a great seal and have extremely highmileage.Available in 62 Durometer, 72 Durometer, or 80 Durometer (+/- 5 Durometer)Also available in short and long sizesSizes available from 2" - 8"

SIZE A B C D WEIGHT2 CUP

SHORT

250mm

2.37560mm

6.000152mm

4.500114mm

1.00025mm

0.3 lb..13 kg

4

380mm

3.37586mm

8.250209mm

6.000152mm

1.50038mm

1.0 lb..453 kg

5.7

4100mm

4.500114mm

10.000254mm

7.500190mm

2.00050mm

2.25 lb.1.0 kg

7.75

6150mm

6.625168mm

12.000304mm

9.875251mm

3.00080mm

4.75 lb.2 kg

11

8200mm

8.500216mm

17.000432mm

13.125333mm

4.000101mm

10.75 lb.5 kg

N/A


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METAL BODY CONSTRUCTION PIGS

Metal Body Construction Pigs come with urethanescraper cups alone or with gauging plates. They may be

mounted on the front and rear of a steel shaft. The cupsor discs are replaceable making this an economicalproduct. Best used to make large diameter and longdistance runs when maximum scraping is required andwhen corrosive products are to be displaced. These arenon-flexible and must go through full port valves and longradius bends.

Wire brushes are also available for these pigs.

Gauging pigs are used for sizing the internal diameter of

your pipeline and can be manufactured to any thicknessor diameter.

Available from 2" up to 16"

Gauging Plate Construction Pig

Wire Brush Metal Body


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SCRAPER CUPS

For use with Construction Metal Bodied pigs

Effective sealing without excessive wear onyour pipe

Strong and Flexible

Urethane Cups are available in sizes from2" - 8"

Size A B C Height

2.0" 1.6" 2.1" 1.73" 0.76"

2.5" 2.05" 2.55" 2.17" 0.76"

3.0" 2.35" 3.19" 2.75" 1.13"

4.0" 3.46" 4.19" 3.57" 1.41"

6" 5.3" 6.27" 5.4" 1.75"

8" 6.96" 8.2" 7.1" 2.04"

10" 8.58" 10.16" 8.75" 2.35"

12" 10.27" 12.22" 11.58" 2.35"


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SPECIALTY

PIPELINE PIGS


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SPECIALTY MAXI DISCS

*For ease around corners including 90's*No breaking of top fins*The pig that is easier to launch thanconventional Maxi Cups & Discs*Will not get caught in valves*Better seal on corners

Available in:Sizes 2" up to 12"

Hollow or Solid60 Duro & Up

SIZE A 1 DISC 2 DISCS 3 DISCS 4 DISCS 5 DISCS 6 DISCS C

2" 2.25" 4" 5" 5.75" 6.5" N/A 2.18"

3" 3.335" 5.25" 6.25 7.25" 8.25" 9.25" N/A 3.20"

4" 4.30" 6.75" 8.5" 10" 11.5" 13" N/A 4.25"

6" 6.37" 9.75" 11.5" 13.5" 15.25" 17.25" 19.25" 6.25"

8" 8.75" 12.5" 15" 17.5" 20" 22.5" N/A 8.50"

10" 11" 18.5" N/A 10.5"

12" 13.0" 24" N/A 12.5"


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SPECIALTY MAXI CUP PIGS

SIZETOP CUP

DIAMETER

BOTTOMCUP

DIAMETER

2 CUPLENGTH

3 CUPLENGTH

3" 3-3/8" 3-3/8" 4.3" 7"

4" 4-3/8" 4-1/2" 5-1/4" 8.7"

Only available in 3" & 4" sizes and with either two or three-cups

Made to go from one schedule of line pipe to another without any problems

More flexible than other urethane pigs for more ease around corners

Available in 60 Durometer, 72 Durometer or 80 Durometer


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BARBEE PIGS

Designed specially for Barber Pig Ball Valve Injectors

One of the best pigs to use for batching

Used as the lead pig in front of Filming pigs in a batching set

*Excellent cleaning & chasing pig*Will manoeuvre around tight 90's easily*Can be used in place of normal pig balls or soft foam pigs*For use with ball valves*For easier pig entry installation*For ease around corners*No breaking of top fins*Standard 70 durometer urethane

*Also available in 60 durometer urethane to fit 250 psi fibreglasspipe.

SIZE A B

2" 2.175" 2.75"

3" 3.375" 4.00"

4" 4-3/8" 6.25"

5.5" 5.50" 6.25"

6" 6-1/4" 8.00

6.4" 6.4" 8.00"

8" 8-1/2" 10.70"

10" 10-1/2" 11.00"

12" 12-1/2" 14.50"

16" 16" 18.50"


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FILMING/COATING PIGS

Specially made for Coating Corrosion Inhibitor into lines

This pig can be made in 60 Durometer, 7 Durometer, or 80 Durometer.

The 60 Durometer pigs are made to be more flexible so they can pass throughdifferent schedules of pipe. The 80 Durometer are made for lines with higherquantities of H2S and C0

2.

Available in:

Sizes 3" - 8"

Notches are machined intothe middle disc.

Total of 12 notches

Bottom View

Back fin is machined down 1/8" under I.D of wall sizeExtra fins can be ordered upon request

SIZE DIAMETER HEIGHT

3" 3-3/8" 5"

4" 4-3/8" 6"

6" 6-1/4" 7-3/4"

8" 8-1/2" 10-3/8"


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MASTER PIGS

Designed for MasterFlo Pig Ball Valve Injectors

*To be used in place of normal pig ballsor soft foam pigs*For easier pig entry installation*For ease around corners*No breaking of top fins*No fluid by-pass, will expand againstthe pipeline wall forming an efficientseal as the pressure differential acrossthe pig increases*Available in 60 Duro & up

*Available in Hollow or Solid Core*Availablewith one or two discs

SIZE A B C

2" 2.25" 3" 2.14"

3" 3.375" 4.47" 3.375"

4" 4.25" 6.78" 4.30"


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Phone: 780-438-0483 Fax: 780-435-5143 Toll-Free: 1-800-871-4160d d k

TUFLEX PIGGING PRODUCTS

Tuflex Pigs (CD Pigs) are designed for thin wall pipe and are able to pass throughSchedule 40 above ground piping and Schedule 40 pipe with 90 degree elbows.

CPP PART # DECRIPTION SIZE A B

PIGT-2CC 2"CC PIG 2" 2.20" 4.75"

PIGT-2CDD 2" CDD PIG 2" 2.20" 4.75"

PIGT-2CDDC 2" CDDC PIG 2" 2.20" 4.75"

PIGT-3CC 3" CC PIG 3" 3.35" 5.91"

PIGT-3CDD 3" CDD PIG 3" 3.35" 5.91"


PIGT-4CC 4" CC PIG 4" 4.35" 7.25"

PIGT-4CDD 4" CDD PIG 4" 4.35" 7.25"


chapter 6 - pipeline pigs

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