Scott, >From Wikipedia. Pigging can just be a single shot thing also. You just drag the pig through a pipe not in use, then flush it.
Pigging >From Wikipedia, the free encyclopedia This article may require cleanup to meet Wikipedia's quality standards. Please improve this article if you can. (January 2008) This article is about the industrial process of pigging, for the sport see pigging (sport). Pigging in the maintenance of pipelines refers to the practice of using pipeline inspection gauges or 'pigs' to perform various operations on a pipeline without stopping the flow of the product in the pipeline. These operations include but are not limited to cleaning and inspection of the pipeline. This is accomplished by inserting the pig into a 'pig launcher' - a funnel shaped Y section in the pipeline. The launcher is then closed and the pressure of the product in the pipeline is used to push it along down the pipe until it reaches the receiving trap - the 'pig catcher'. If the pipeline contains butterfly valves, the pipeline cannot be pigged. Ball valves cause no problems because the inside diameter of the ball can be specified to be the same as that of the pipe. Pigging has been used for many years to clean larger diameter pipelines in the oil industry. Today, however, the use of smaller diameter pigging systems is now increasing in many continuous and batch process plants as plant operators search for increased efficiencies.[1] Pigging can be used for almost any section of the transfer process between, for example, blending, storage or filling systems. Pigging systems are already installed in industries handling products as diverse as lubricating oils, paints, chemicals, toiletries, and foodstuffs. Pigs are used in lube oil or painting blending: they are used to clean the pipes to avoid cross-contamination, and to empty the pipes into the product tanks (or sometimes to send a component back to its tank). Usually pigging is done at the beginning and at the end of each batch, but sometimes it is done in the midst of a batch, e.g. when producing a premix that will be used as an intermediate component. Pigs are also used in oil and gas pipelines: they are used to clean the pipes but also there are "smart pigs" used to measure things like pipe thickness along the pipeline. They usually do not interrupt production, though some product can be lost when the pig is extracted. They can also be used to separate different products in a multiproduct pipeline. Contents [hide] 1 Etymology 2 Pigging in production environments 2.1 Product and time saving 2.2 Environmental issues 2.3 Safety considerations 2.4 Intelligent pigging 3 Pipeline inspection gauge 4 See also 5 External links [edit]Etymology Pigs get their name from the squealing sound they make while traveling through a pipeline.[citation needed] (Disputed: 'PIG' is an acronym derived from the initial letters of the term 'Pipeline Inspection Gauge' or possibly 'Pipeline Inspection Gizmo' or 'Pipeline Internal Geometry') [edit]Pigging in production environments [edit]Product and time saving A major advantage of piggable systems is the potential resulting product savings. At the end of each product transfer, it is possible to clear out the entire line contents with the pig, either forwards towards the receipt point, or backwards to the source tank. There is no requirement for extensive line flushing. Without the need for line flushing, pigging offers the additional advantage of a much more rapid and reliable product changeover. Product sampling at the receipt point becomes faster because the interface between products is very clear, and the old method of checking at intervals, until the product is on-specification, is considerably shortened. Pigging Systems can also be operated totally by a Programmable Logic Controller (PLC). [edit]Environmental issues Pigging has a significant role to play in reducing the environmental impact of batch operations. Traditionally, the only way that an operator of a batch process could ensure a product was completely cleared from a line was to flush the line with a cleaning agent such as water or a solvent or even the next product. This cleaning agent then had to be subjected to effluent treatment or solvent recovery. If product was used to clear the line, the contaminated finished product was downgraded or dumped. All of these problems can now be eliminated due to the very precise interface produced by modern pigging systems. [edit]Safety considerations Pigging systems are designed so that the pig is loaded into the launcher, which is pressured up to launch the pig into the pipeline through a kicker line. The pig is removed from the pipeline via the receiver at the end of each run. All systems must allow for the receipt of pigs at the launcher, as blockages in the pipeline may require the pigs to be pushed back to the launcher. Some systems are designed to pig the pipeline in either direction. Most pigging systems are like this as the pigs must be removed, as many pigs are rented, pigs wear and must be replaced, and cleaning pigs push contaminants from the pipeline such as wax, foreign objects, hydrates, etc, which must be removed from the pipeline. There are inherent risks in opening the barrel to atmosphere and care must be taken to ensure that the barrel is depressured prior to opening. If the barrel is not completely depressured, the pig can be ejected from the barrel and operators have been severely injured when standing in front of an open pig door. When the product is sour, the barrel should be evacuated to a flare system where the sour gas is burnt. Operators should be wearing a self-contained breathing apparatus when working on sour systems. A few pigging systems utilize a "captive pig", and the pipeline is only opened up very occasionally to check the condition of the Pig[2]. At all other times, the pig is shuttled up and down the pipeline at the end of each transfer, and the pipeline itself is never opened up during process operation. These systems are not common. [edit]Intelligent pigging Inserting a pig into a natural gas pipeline Modern intelligent pigs are highly sophisticated instruments that vary in technology and complexity by the intended use and by manufacturer. An intelligent pig, or smart pig, is basically a computer that collects various forms of data during the trip through the pipeline. The computer part, consisting mostly of electronics, must be sealed to prevent leakage of the pipeline product into the electronics. Sealing is a very important aspect as the products in the pipeline can range from highly basic to highly acidic and can be of extremely high temperature. Many pigs use specific materials according to the product in the pipeline. Power for the electronics is provided by onboard batteries which also must be sealed from the product environment. Recording of data may be by various means ranging from analog tape in a reel-to-reel format, digital tape or solid state memory in more modern digital units. The technology used to accomplish the service vary by the service required and the design of the pig, each pigging service provider may have unique and proprietary technologies to accomplish the service. Surface pitting and corrosion, as well as cracks and weld defects in steel/ferrous pipelines are often detected using Magnetic Flux Leakage (MFL) pigs. Other "smart" pigs use ultrasonics to detect pipe defects. Caliper pigs can measure the "roundness" of the pipeline to determine areas of crushing or other deformations. Some smart pigs can combine technologies such as MFL and Caliper into a single tool. During the pigging run the pig is unable to directly communicate with the outside world due to the distance underground or underwater and/or materials that the pipe is made of. For example, steel pipelines effectively prevent any reliable radio communications outside the pipe. It is therefore necessary that the pig use internal means to record its own movement during the trip. This may be done by gyroscope-assisted tilt gauges, odometers and other technologies. The pig will record this positional data so that the distance it moves along with any bends can be interpreted later to determine the exact path taken. Location verification is often accomplished by surface instruments that record the pig’s passage by either audible or gravinometric (or other) means. The sensors will record when they detect passage of the pig; this is then compared to the internal record for verification or adjustment. The external sensors may have GPS capability to assist in their location or even to transmit the pig’s passage, but the pig itself usually cannot use GPS as it requires being able to “see” (in satellite terminology) the satellites. After the pigging run has been completed, the positional data is combined with the pipeline evaluation data (corrosion, cracks, etc) to provide a location-specific defect map and characterization. In other words, the combined data will tell the operator the location and type and size of each pipe defect. This is used to judge the severity of the defect and help repair crews locate and repair the defect quickly without having to dig up excessive amounts of pipeline. By evaluating the rate of change of a particular defect over several years, proactive plans can be made to repair the pipeline before any leakage or environmental damage occurs. [edit]Pipeline inspection gauge A pig in a cutaway pipeline A "Pig" launcher/receiver, belonging to the natural gas pipeline in Switzerland. A pipeline inspection gauge or pig in the pipeline industry is a tool that is sent down a pipeline and propelled by the pressure of the product in the pipeline itself. There are four main uses for pigs: physical separation between different liquids being transported in pipelines; internal cleaning of pipelines; inspection of the condition of pipeline walls (also known as an Inline Inspection (ILI) tool); capturing and recording geometric information relating to pipelines (e.g. size, position). The original pigs were made from straw wrapped in wire used for cleaning. They made a squealing noise while traveling through the pipe, sounding to some like a pig squealing. The term "pipeline inspection gauge" was later created as a backronym. One kind pig is a soft, bullet shaped polyurethane foam plug that is forced through pipelines to separate products to reduce mixing. There are several types of pigs for cleaning. Some have tungsten studs or abrasive wire mesh on the outside to cut rust, scale, or paraffin deposits off the inside of the pipe. Others are plain plastic covered polyurethane. Pigs cannot be used in pipelines that have butterfly valves. Inline inspection pigs use various methods for inspecting a pipeline. A sizing pig uses one (or more) notched round metal plates that are used as gauges. The notches allow different parts of the plate to bend when a bore restriction is encountered. More complex systems exist for inspecting various aspects of the pipeline. Intelligent pigs, also called smart pigs, are used to inspect the pipeline with sensors and record the data for later analysis. These pigs use technologies such as Magnetic flux leakage (MFL) and ultrasonics to inspect the pipeline. Intelligent pigs may also use calipers to measure the inside geometry of the pipeline. In 1961, the first intelligent pig was run by Shell Development. It demonstrated that a self contained electronic instrument could traverse a pipe line while measuring and recording wall thickness. The instrument used electromagnetic fields to sense wall integrity. In 1964 Tuboscope ran the first commercial instrument. It used MFL technology to inspect the bottom portion of the pipeline. The system used a black box similar to those used on aircraft to record the information. A pig has been used as a plot device in three James Bond films: Diamonds Are Forever, where Bond disabled a pig to escape from a pipeline, The Living Daylights, where a pig was modified to secretly transport a person through the Iron Curtain, and The World Is Not Enough, where a pig was used to move a nuclear weapon through a pipeline. A pig was also used as a plot device in the Tony Hillerman book The Sinister Pig where an abandoned pipeline from Mexico to the United States was to use a pig to transport illegal drugs. On Tue, Mar 30, 2010 at 4:33 PM, Scott A. Futrell <sco...@ffcdi.com> wrote: > Ron, > By "pig" do you mean inflatable plug like Cherne manufacturer's? If so, I > didn't know those were used for "cleaning". I guess it would work as long as > there is accountability and it gets out of the ug before the fire... > > Scott Futrell > > (763) 425-1001 Office > (612) 759-5556 Cell > > -----Original Message----- > From: sprinklerforum-boun...@firesprinkler.org > [mailto:sprinklerforum-boun...@firesprinkler.org] On Behalf Of Ron Greenman > Sent: Tuesday, March 30, 2010 4:03 PM > To: sprinklerforum@firesprinkler.org > Subject: Re: Underground flushing velocities > > The objective is to move the water fast enough to move the crap and to > move enough water that there's enough flow to get the stuff to the > outlet so I think (dangerous) flow rate is more important. If I put my > big thumb over the end of your 24" pipe I'll get good velocity but > stuff might get hung up at the thumb end 'cause I got a little hole. > I'm just cleaning out debris so I can manually remove it if I get it > to the end. If moving a lot of water was the issue so that any given > slug of water could be traced as fully moving along the pipe and I was > trying to scrub the pipe walls, and it was moving slow I'd probably > fail. I don't need to scrub the walls of a new pipe, just move the > loose stuff like gloves, 2x4s, rags, tools and bedsheets (yes, I've > found a bed sheet, came from a hospital in an area where there were no > hospitals) then velocity is key. If I can't scrub because velocity is > too low unless I try to restrict exiting volume then I can always > scrub with a pig. So after all that I'm agreeing that the velocity > (10fps) is the bottom limiting factor. But it isn't really clearly > stated. > > On Tue, Mar 30, 2010 at 1:47 PM, <craig.pr...@ch2m.com> wrote: >> NFPA 24 says the following: >> >> NFPA 24: 10.10.2.1.3 The minimum rate of flow shall be not less than one of >> the following: >> (1) Hydraulically calculated water demand flow rate of the system, including >> any hose requirements >> (2) Flow necessary to provide a velocity of 10 ft/sec (3.1 m/sec) in >> accordance with Table 10.10.2.1.3 >> (3) Maximum flow rate available to the system under fire conditions >> >> >> >> >> >> Debate is whether that means that the flow rate dictates the velocity and it >> has no absolute requirement or the minimum is 10fps. >> >> Based on wording in the Appendix it would appear that 10fps is the desired >> minimum. >> >> So for example I have a flow rate of 8000 gpm (fire flow per local AHJ) and >> the line size ends up being 24" Vel= 6.74 fps. Is that acceptable per NFPA >> 24, 10.10.2.1.3? There are issues with the distance between source and pump >> suction and larger pipe equal less friction loss but also lowers velocities. >> >> I read it that it can be less than any one of the following with 10fps being >> the minimum. Sometimes simpler wording for non-FP types would make life >> easier. <sigh> >> >> Thought, comments, etc????????? >> >> Craig L. Prahl, CET >> Fire Protection Specialist >> Mechanical Department >> CH2MHILL >> Lockwood Greene >> 1500 International Drive >> PO Box 491, Spartanburg, SC 29304-0491 >> Direct - 864.599.4102 >> Fax - 864.599.8439 >> craig.pr...@ch2m.com >> http://www.ch2m.com >> >> _______________________________________________ >> Sprinklerforum mailing list >> Sprinklerforum@firesprinkler.org >> http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum >> >> For Technical Assistance, send an email to: supp...@firesprinkler.org >> >> To Unsubscribe, send an email to:sprinklerforum-requ...@firesprinkler.org >> (Put the word unsubscribe in the subject field) >> > > > > -- > Ron Greenman > Instructor > Fire Protection Engineering > Bates Technical College > Tacoma, WA > > Member: > SFPE, ASCET, NFPA, AFSA, NFSA AFAA, NIBS, WSAFM, WFC > _______________________________________________ > Sprinklerforum mailing list > Sprinklerforum@firesprinkler.org > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > For Technical Assistance, send an email to: supp...@firesprinkler.org > > To Unsubscribe, send an email to:sprinklerforum-requ...@firesprinkler.org > (Put the word unsubscribe in the subject field) > _______________________________________________ > Sprinklerforum mailing list > Sprinklerforum@firesprinkler.org > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > For Technical Assistance, send an email to: supp...@firesprinkler.org > > To Unsubscribe, send an email to:sprinklerforum-requ...@firesprinkler.org > (Put the word unsubscribe in the subject field) > -- Ron Greenman Instructor Fire Protection Engineering Bates Technical College Tacoma, WA Member: SFPE, ASCET, NFPA, AFSA, NFSA AFAA, NIBS, WSAFM, WFC _______________________________________________ Sprinklerforum mailing list Sprinklerforum@firesprinkler.org http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: supp...@firesprinkler.org To Unsubscribe, send an email to:sprinklerforum-requ...@firesprinkler.org (Put the word unsubscribe in the subject field)
