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Leakproof Pipeline

Leakproof Pipeline

(OP)
Is it possible to construct a pipeline that is reasonably leakproof. Does it have to be exposed, buried, or whatever? The actual construction? materials? single or double wall? monitors for leakage? inspection both during construction and in service? cost? any other issues?


Dik

RE: Leakproof Pipeline

Sorry, not so sure what are the questions.
Everything is possible....

RE: Leakproof Pipeline

You've posted a lot. What brings this question?

RE: Leakproof Pipeline

(OP)
3DDave:

Just wondering if it is possible to construct a leak proof pipeline and what the issues are.

Dik

RE: Leakproof Pipeline

As designers we do our best.
As less flanges as possible is one of the issues.

RE: Leakproof Pipeline

Interesting question.

The answer is both yes and no.
Yes, IMO, and practically speaking, you can build a leakproof pipeline.

The second question is, "Is it practical?"
No, IMO, , leaving economic practicality aside, if it is practical, it will only be practical for a limited time. Design life and maintenance costs will eventually catch up to practicality of operating it any longer. As has been proven an number of times lately, it is not likely to catch up to corporate greed. Operating life will be extended past design life to the point where maintenance failure overtakes utility.

Third question is, "Is it practical to be operated as a leakproof pipeline?" I think this is the most problematic. If it is practical to build and operate for a limited time, you've got a few other factors to consider as well. Statistically there are three most consequential and very important causes of leaks. If you were always able to maintain complete control of these variables, it might be possible, but the practicality of what that means is, I don't think so. At least not all the time.

Factors
1.) External Corrosion
2.) Instrument and Control Errors (control may involve human factors)
3.) Third Party Damage
4.) Costs of monitoring and correccting all the above, before a leak occurs.

Mitigations
1.) External corrosion difficult to see on a buried pipeline and expensive to repair, if you do manage to locate it in time.
High cost to examine. Errors in prediction of remaining life.
Not buried would subject the pipeline to other more dangerous factors, coating damage? Vandalism .... bullets?, socio-environmental unacceptability, PROPERTY VALUE EFFECTS, etc. Would you really want an above ground pipeline in your neighborhood? Not me, "leakproof" or not. Leak detection... like terorist cameras... are too late to do me any good.

2.) Increased use of instrument and controls is increasingly subject to errors.
Will new technology and increased use improve control, or degrade integrity due to hacking and instrument failures. Accidential overpressures. Human control room response errors. Level and relief valve pressure controls failing more. More complex, expensive, error-prone maintenance.

3.) Third party damage is causing the most loss of life and property damage. There is little control of the situation now. There is a very high cost of protection from this factor. Lots of farmers and road repair crews and sewer installers out there. Offshore, protecting for an anchor dropped in the wrong place and you might be burying 18 ft or more everywhere?

4.) Other factors. How long a pipeline and location. Some things might be far more practical for a short pipeline of 1-10 km, but not practical at all for 1000 km of onshore or offshore.

I add
5.) Regional security. Leakproof and terrorist activities aren't exactly compatible under any circumstances. All PRACTICAL terrorist defences of pipelines of normal length effectively say that protecting pipelines from terrorist, or extreme vandalism is impossible from a practical standpoint. It is recognised that high cost of military patrols necessary to prevent leaks and response times allow effective protection only at high profile nodes of delivery hubs, terminals. Pump stations may or may not be included. Protecting every km of pipeline joint and emergency valve stations along the root 24/7 just is not practical.

So, consider those factors and the cost of mitigations and I think you might be able to get away without leaks for a relatively short time. The answer is probably, "Yes. Theoretically you can build a leakproof pipeline, but the practicality of the situation is, NO, or, Only for a limited time.

There's probably more I'll think of later.

Technology is stealing American jobs. Stop visas for robots.

RE: Leakproof Pipeline

What is "reasonably leak proof" compared to "standard" pipeline design?

The most leak proof pipeline I've ever seen was a 12" high pressure ( 70 bar) gas pipeline which ran 3km along a beach front road where hundreds if not thousands of people could be present on a nice summers day.

This line was buried with 2 to 2.5m cover (extra depth is good for risk reduction), had a coloured red concrete slab on top projecting out beyond what a digger could reach, was 19.1mm thick ( much more than required for pressure containment), had a fibre optic cable above that so that any digging which breached it alarmed with a location. That was 20 years ago and now you would make that FO cable act as an intruder / third party pro active detection system. Every weld was x rayed and the whole thing hydrotested to a high level (105% SMYS). Standard 3LPP coating and cathodic protection system.

The pipeline could be internally inspected so any external corrosion ( it was dry sales gas so no internal corrosion) could be monitored on a 3-5 year basis.

The only extra thing they could have done was make it a true pipe in pipe double containment where inner pipe failure wouldn't escape and also the outer pipe would act as extra protection, but I think that was seen as really going too far.

Cost was about 3-5 times "normal" pipeline length but the alternatives were even more costly as involved complex drills and a longer length.
Now that's about as "leak proof" as you can "reasonably" get IMHO.

Otherwise BI has the basics nailed - yes feasible especially for short small diameter lines, large long distance lines - not economic.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Leakproof Pipeline

(OP)
Big and Little Inches:

Great replies, in particular Big Inch, a lot of effort went into both replies.

My son asked me if it was possible to design a pipeline that was leakproof... and, I couldn't give him an answer. I knew it was possible to construct one that was nearly leakproof, and, that as more effort went into it (and cost) the chances of it leaking were diminished. I didn't know if buried, or exposed was better and I didn't know what construction would be involved for the actual piping. I thought properly welded would be better than bolted, but, wasn't sure. Part of the issue, I guess, is assigning a maximum life expectancy with necessary inspections. I don't know how they are inspected. For small pipes, a small robot going down the pipe, X-raying welds?

again, thanks Dik

RE: Leakproof Pipeline

Yup,

buried better than above ground
deeper you bury it the better
Welded better than flanged,
Thicker better than thinner
extra things in the way to stop someone digging it up
Sensors / cables to detect someone digging

All cost more than normal.

Internal inspection is intelligent pigs - look them up
One of these bad boys


Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Leakproof Pipeline

All of the 'pipelines' in the wall of my house are leakproof, so I guess the answer is 'yes, it is possible'.

RE: Leakproof Pipeline

(OP)
TenPenny... maybe just a matter of time. I'm thinking of pipelines that carry materials that could be damaging to the environment in the event of a leak. My son was asking about a pipeline for oil products from Alberta to the Pacific Ocean.

Dik

RE: Leakproof Pipeline

Surprisingly enough operating at higher pressures doesn't have all that much to do with either explosions, property damage or death count... according to the statistics. Pipeline stopping leaks rarely happen near or above maximum allowed operating pressures (MAOP). Probably because most of the length of a typical pipeline does not operate at MAOP anyway. That means there will naturally be more exposure to damage from both third party activity and corrosion in the relatively longer lengths regions where lower pressures prevail.

Technology is stealing American jobs. Stop visas for robots.

RE: Leakproof Pipeline

While BI and LI touched upon it, the biggest issue with leakproofing is not an engineering problem, per se; it's an economics problem. Whatever the cost adder you wish to imagine for the pipe that you want to call "leakproof," what is the penalty for having a leak, and how long does it take for your investment (the added cost) to break even. These questions are engineering related, in a sense, as every engineering decision tends to shaped by the economics and deepness of pocketbooks. Ford did that analysis for the Pinto, and decided that the risks were sufficiently low enough to justify not adding a bracket that would have prevented loss of life during a particular type of rear-end collision: https://philosophia.uncg.edu/phi361-metivier/modul... While pipes might not necessarily rise to the level of loss of life upon a leak, there certainly are cost factors in environmental cleanup, etc., coupled with the rarity of such occurrences, given proper and adequate maintenance and testing. So, when the pipe is a tiny part of an overall, large, cost, such that a 2x or 3x pipe cost is inconsequential, then it's likely someone could decide to make that pipe.

However, in the majority of the cases, there will more likely be cries of "gold-plated pipes," and, "when are we getting our investment back," than any concern about an infrequent, and usually, low-cost, event. While we don't like to think about the life and death costs of everything we do, buy, or use, they are there, buried on some spreadsheet, in some archive. The bottom line is that we cannot afford to make everything literally bulletproof, so we live with those risks, even though the average Joe is completely unaware of the risks and costs thereof that someone has assigned to him.

We treat risks asymmetrically, and disproportionately, anyway. We're more concerned about terrorist attacks in the US, even though they've killed fewer people in the 16 years since 9/11 than the death toll from 2 months of traffic fatalities. We willingly and blindly ignore the risks of dying in our cars, even when presented the data, over and over. People continue to text while driving, even on the freeway, despite repeated warnings. Do we or should we allow Darwin to deal with those people?

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: Leakproof Pipeline

(OP)
I gather that with proper planning and design, for additional costs, pipelines can be made much safer. It's a matter of determining where the balance is. Have there been any studies done on this? I cannot think of the term, but, there were studies done in economics when I went to university using linear programming to determine items that may have been similar.

Dik

RE: Leakproof Pipeline

Quote:

I gather that with proper planning and design, for additional costs, pipelines can be made much safer.

Not a totally supportable assertion IMHO.

Google "Hanford" for examples of what an unlimited budget cannot do.

Mike Halloran
Pembroke Pines, FL, USA

RE: Leakproof Pipeline

(OP)
Thanks MIke... anything to add that could improve the safety?

Dik

RE: Leakproof Pipeline

I would bet dollars to donuts that anything cheap that could be done has already been done. Clearly, there is some need to appease public opinion, so low-hanging fruit have already been gathered so that the pipeline companies can use them as examples of their proactiveness in pipeline safety.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: Leakproof Pipeline

(OP)
Have enough constraints to set up a linear programming model for my TI Nxpire calculator that can do the linear plots w/fill... Had nothing better to do this evening... forgot a 'whole bunch' about linear programming, but, it's like 'riding a bike'.

Dik

RE: Leakproof Pipeline

No LP required IMO. It is well known in the industry that corrosion is by far the #1 cause of all leaks and third party activities cause the most property damage and loss of life.

1.) Pipelines are already installing the components necessary to use the inspection pigs LI pictured above in all new regulated pipelines and over the next 20 years or so for old pipelines.

2.) There are One Call programs operating in every state that contractors should call before digging. More could always be done to educate contractors, as that is critical and ... a never ending battle.

3.) A regulation requiring excess flow shutoff valves is being contemplated, but they won't activate until after a break or leak occurs.

4.) A new federal regulation to extend regulatory authority to include a number of rural and some other pipelines that have not been previously regulated is being contemplated. Pipeline companies and trade lobbyist organizations have commented during the regulatory process that they are against this provision. That is not surprising, especially given the current political climate. Yet they were not anywhere to be seen when this Plains All American Pipeline Co pipeline leaked 140,000 gal. That pipeline is offshore, yet in state waters and apparently not included within the federal regulatory program, falling into a regulatory black hole between federal and state waters. Recently sold between two companies, neither one apparently knowing what its operational state was at the time and eventually finding out the hard way that it was actually pretty damn poor.
2015 California offshore pipeline leak

I think that public opinion is so bad at the moment that, no matter what the cost, certain things will have to change. Frankly most pipeline companies are great money makers and can afford to play the game no matter what the house rules are, so drain the swamp, build some safe pipelines and pump out what's left.

What I would like to know...
Is it my imagination, or does the rest of the world's pipelines appear to be safer. Is it that the USA simply has so many more pipelines? I don't think for the most part there is any essential differences in design. Codes are the same ASME as the US, nearly exact copies, or very similar. So, for example, are European pipelines constructed better? Operated better? Inspected better? Maintained better. All the above, or is it just my imagination.

Technology is stealing American jobs. Stop visas for robots.

RE: Leakproof Pipeline

"Is it my imagination, or does the rest of the world's pipelines appear to be safer."

I vote imagination; I think the rest of the world does not play by the same set of rules as the US. Things are less transparent and people don't expect to survive certain things that are a given in the US, nor do they have the same level of influence on regulations.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: Leakproof Pipeline

I think it is not (entirely my imagination, but don't yet have the stats to prove it. I live in the rest of the world and IMO many nationalities actually have a VERY MUCH higher standard of expectations of many things. We expect national health care, for example. We expect high quality, safety, to have our paid-for seat on the plane w/o violence, clean water and air, personal data protection, no GM foods... even if we don't all the time get it. Why do you think they keep on looking for MH 370 for so long after all hope of finding any traces of it were more than obviously futile. The Malay and Chinese people expected it and the company expected that it was necessary to provide it. The expectations of USA nationals has been low ever since Blackhawk Down was released and worsened when no weapons of mass destruction were ever found in Iraq and those were recent high points.

Technology is stealing American jobs. Stop visas for robots.

RE: Leakproof Pipeline

I would like to see whether statistically in terms of incidents per km there is much difference.

It could just be the sheer number and length of pipelines in the US.

However there is something to it I think.

Non US pipeline codes whilst using B31.4/8 as their base add in manufacturing pipe tolerance and, in general, are a bit more conservative.

In Europe and many other countries, the national Gas network started life as government owned companies and naturally tended to a "safer" design and also spent money on maintence and inspection. The root of the magnetic pig design came from the study centre of the UK gas industry where they developed the technology when it was a govt funded business.

when you add in the age of much of the US pipeline network compared to the ROW. the increase in steel quality over time and a higher population density meaning risks need to be lower to be acceptable then overall I suspect the US does have a higher incident rate. That's certainly the impression....

"Things are less transparent and people don't expect to survive certain things that are a given in the US, nor do they have the same level of influence on regulations"
Hmmm, Maybe in Africa and parts of Asia, but not in Europe.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Leakproof Pipeline

I got it.

I think what makes the biggest difference is that, if a textile factory, or a pipeline blows up and people get killed in Russia, Pakistan, China, India, Indonesia, Bangladesh and many other countries, FIRST they put the owner in jail, then they sort out over the next few months. If the boss is guilty in China, maybe he gets whacked.

Maybe foreign pipe mfg and coating and corrosion control procedures are better.

Technology is stealing American jobs. Stop visas for robots.

RE: Leakproof Pipeline

Normally the "sort it out" involves transfer of money from one party to another....

A little off subject, but this was a case in point. $ 190MM apparently though how much ever got to the front line is not available.... https://business-humanrights.org/en/trafigura-laws...

They did imprison the chief Exec for a while when he went to visit.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Leakproof Pipeline

(OP)
Thanks gentlemen... some really great information. It'll take a few days to sift through the answers.

"You've posted a lot. What brings this question?" just curious, and, couldn't answer my son's question (and I thought I knew everything <G>). It, however, was a good question.

Dik

RE: Leakproof Pipeline

(OP)
MK3223:
I was going through the responses and came across the following:

"Sorry, not so sure what are the questions.
Everything is possible...."

It being a slow day, I realised that you imply that "Nothing is Impossible"... and then had the thought, "Ever try to get off a mailing list?"

The pipeline repair thread is also pretty good. Have a great day...

Dik

RE: Leakproof Pipeline

Trying to pay off my taxes, so I called HMRC and got the exact balance. Making the transfer to pay it off took about an hour I guess. Today I received a bill, posted in the mail from HMRC, England. Yes, precisely, a bill for 0.10 GBP. The amount of penalty added for the time it took to make the tranfer. At that rate it'll be awhile before I get off that list.

Technology is stealing American jobs. Stop visas for robots.

RE: Leakproof Pipeline

13 cents...

did the stamp cost more?

RE: Leakproof Pipeline

(OP)
money's no object... intelligence, however, seems to be at a premium.

Dik

RE: Leakproof Pipeline

Ya it cost them £1.17 to send a bill for £0.10 smile That's greed at it's worst.

Technology is stealing American jobs. Stop visas for robots.

RE: Leakproof Pipeline

Truck it or train it. Of course this doesn't stop that mode of transport from skidding off the rails and blowing up all over the place. I find it funny how we even need to ship our resources through a pipeline to some other place so they can use it. It is all driven by money hungry mad men. No matter where you go all the natural resources are right in your back yard. But if you want more, which we all do, you will need to get it shipped in from somewhere else. It's too bad the environment is the controlling factor in all this or we could just run all we need down our river systems (leak proof and all if you take out the environment factor). Star Trek might have an answer in one of their episodes.

RE: Leakproof Pipeline

(OP)
The question arose because of a dialogue with my son. We have an issue in Canada with one province wanting to run a pipeline across British Columbia to the Pacific Ocean to supply China. The federal government wants to do the pipeline as well as the source (Alberta tar sands). The route is through pristine natural resource area... I'd mentioned to my son that pipeline is likely the safest method, but, they often leaked, causing problems. Not being a piping person, I had no (little) idea of what could be done to improve this history. I'll summarise the thread and send it on to a couple of people I know for consideration.

Dik

RE: Leakproof Pipeline

The Gateway. You can probably understand why Keystone and Dakota Access have had the same problem. Pipeline are the best way, at least the safest and by far the cheapest form of overland transport and they are the most environmentally friendly way to move large quantities of most fluids. Trees must be removed, but other than temporary construction activities, there is little remaining impact on nature, if things go as planned. One large pipelines can take 10s of thousands of trucks off the roads, reducing emissions and improving road safety. They also put thousands of truck drivers off the roads too ... but their biggest problem yet is that they need lots and lots of land, that they supposedly can't afford to buy outright. They only lease the rights to use the land ... basically forever .. at a relatively low cost. So, they are essentially able to operate cheaper than railroads for example, because they use cheap public and private lands. Now after using all that cheaply obtained land, they want the public to accept the risks of operating the pipeline on top of it. True, pipelines create jobs, at least some somewhere, and pay taxes, at least some somewhere, however they don't create a whole lot of employment, after subtracting the truck drivers out of work it's probably negative, and some pay very little tax, especially if partnerships are structured the right way in the USA. So what remains in many peoples minds is, should we let them use cheap land in return for the limited environmental benefits of reduced trucks and emissions, or not. If we do, will the benefits of that compensate for the risk we take of leaks and line breaks on our lands. Many people think not. This is especially true for BC, since little or none of the oil production benefit will go to BC, yet BC will have more miles of potentially leaking pipeline risk to accept. On top of that, there will be quite a few more oceangoing tankers operating in the Sound. On top of that, will BC get much tax revenue from the oil companies that operate and pay taxes in Alberta. Will BC get the benefit of burning that oil as fuel? No, it's going to Japan. Considering all those items on the wrong side of the list, the whole risk-reward scenario of the Gateway project from BC's perspective is tilted very much towards Alberta's favour. That's the same reason Keystone had such a hard road to hoe in the USA. USA gets the risk and pollution, but not much else. Gateway is best from a USA standpoint, as BC would get the risk and pollution. Can we build a leakproof pipeline to eliminate the potential risk of leaks? I think it's a tall order. Better to study the statistical leak rate and see if you can successfully mitigate the effects of that, or ... take the best route for BC, which could be send it through Keystone.

Technology is stealing American jobs. Stop visas for robots.

RE: Leakproof Pipeline

Double walled pipe has been done many times ... for short pipelines.
PROBLEM: VERY EXPENSIVE, esp for long pipelines.

"He's declaring war on the planet itself."- Vicente Fox

RE: Leakproof Pipeline

(OP)
Thanks FIG Journey... I'll follow up on the article.

BigInch... cost, although an issue, has too often resulted in 'skimpy' designs and subsequent failures. It's an issue, albeit, a minor one.

Dik

RE: Leakproof Pipeline

Nothing new there I'm afraid.

It is essentially a leak detection process, not a preventative system.

Such systems actually encourage corrosion because the outer surface of the inner pipe is not protected by your cathodic protection system which actively prevents corrosion.

If you don't make the outer pipe pressure containing, then the stuff in the inner pipe still comes out, especially if a major fault develops.

Then it starts to cost an awful lot more than 25% more.

The ability now of fibre optic cable detection systems far outstrips this student project. They really do prevent leaks by warning of land movements, 3rd party interference and also detect a leak with pin point accuracy. They are not cheap, but pays dividends in the long run.

Combine it with a well executed internal inspection system every 5 years and then doing something about the things it finds and you're a long way towards your goal of no leaks and no harm the environment.

A well designed, well installed and well inspected pipeline is the safest and cheapest means of transporting fluids long distances. The key is the "well" bit.

Yes, the issue of risk vs reward will always appear. The Chad Cameroon pipeline had and maybe still has the same issues - Chad gets all the revenue and Cameroon, which has 3/4 of the length of the export pipeline, was only getting cents per barrel until very recently. Oil companies hate paying per barrel extra tariffs so this sort of arrangement is not common, but is one way of sharing the risk reward issues around.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Leakproof Pipeline

Right. Exactly part of my argument. The higher the cost, as they are for pipe-in-pipe welding, the more tendency there is for contractors to find those cheaper, and more risky, work-arounds.

Pipe-in-pipe has it's issues as well. Temperature differences between inside and outside pipes mean compression inside, tension outside, or maybe the reverse in summer. Sometimes the component pipes need to be prestressed before welding up. You can see that pipe-in-pipe involves welding the inside pipe together with the outside pipe ... at each end. Just trimming and keeping that end dimensioning tolerance while welding is difficult. Now do the same to the next length of pipe-in-pipe. You've made 8 welds already; an inside weld and an outside weld at both ends for two pipe lengths already now. Now hold those two lengths together and weld them to each other. AS you can see, when I said expensive, I meant expensive. 25% more? NO WAY! I meant Project-Killing expensive. This is large diameter. Say tripple the usual single wall pipe cost, the outside pipe is larger, otherwise I would have simply doubled it. 10x more for welds alone. QA/QC, Shipping handling. Carrying cost of the much longer construction time will be huge. I was thinking at least 5 times as expensive. Gateway has two parallel large diameter - pipelines. What's the estimated cost of Gateway now, 6 billion, 8 billion, 10B? OK now call them up and tell them it's going to cost them 30-50 BILLION and let me know how the rest of that conversation goes. I think they'll be looking at exporting via Keystone before end of business today. No worries, that's the best outcome for BC. If that's what you want, might be a good strategy to ask for pipe-in-pipe.



"He's declaring war on the planet itself."- Vicente Fox

RE: Leakproof Pipeline

(OP)
Thanks, BigInch...

Dik

RE: Leakproof Pipeline

Pipe-In-Pipe has only been used for short, smaller diameter flowlines (gathering), carrying hot oil, insulated in the annulus, offshore, cool waters .. that I am aware of.

"He's declaring war on the planet itself."- Vicente Fox

RE: Leakproof Pipeline

Watch it. Reading that kind of stuff is the first step in turning yourself into oilfield trash.

"He's declaring war on the planet itself."- Vicente Fox

RE: Leakproof Pipeline

This is all very interesting. What is the normal life of a pipeline? In my area there is part of the UK natural gas distribution network which I remember being laid in 1968. The pipe is underground and around 24" diameter and judging by the absence of a smell or a big hole has remained safe for all that time. I know it is examined by helicopter on a fairly regular basis for nearby activity as I have heard of farmers being challenged.
The water mains seem much more prone to failure and there have been some major bursts causing serious damage to houses.

RE: Leakproof Pipeline

Many pipelines (outside the oil field gathering systems) that transport realtively pure, clean, dry corrosion free products, do not have a defined operating life based on their design specification. In my opinion you can assume that othey will last 50 years, and with care, that can be extended to 75 years. Up to and ver 75 years becomes increasingly problematic and I assume only with good care, internal and external coorosion inspection, coating removal and repair as necessary.

"He's declaring war on the planet itself."- Vicente Fox

RE: Leakproof Pipeline

Pretty good. One or two things I would change, but pretty minor.

I find it astonishing it took until 1994 for new pipelines to be piggable as part of the regulations and that gas pipelines has liquid in them(!!)

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Leakproof Pipeline

I don't think You ever really get all the liquids out, especially if your pipeline goes from Texas to Minnesota, warmer to colder and colder. The water and condensates keep on dropping out little by little as the temperature of the pipe and gas inside decrease.

"He's declaring war on the planet itself."- Vicente Fox

RE: Leakproof Pipeline

Derby loco,

Agree with BI - can be a very long time. Gas pipelines can end up being restricted by fatigue and the daily pressure variations causing stress fluctuations, but in most pipelines this is 50 years plus.

The coating has a finite life and is often the first thing to start causing issues and increased number of external corrosion holes which need repair.

One thing though - the high pressure network in the UK is no longer odourised. The odour is now put in at the pressure let down stations before it goes to domestic customers but things like high pressure transmisison lines and pipelines to power stations have no odour.

The helicopter is for spotting infringements on the pipeline easement and any construction work on or close to the pipeline which was not previously notified. Sometimes they use infrared cameras to spot any area of lower temperature which can indicate a small leak as the gas cools a lot from high pressure to ambient air pressure and shows up as a cold spot.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Leakproof Pipeline

(OP)
BigInch:

I'm approaching my 70th with 45+ years of experience, and, have never lost my childhood curiosity. I'm a bit of a techno packrat. When I come across interesting 'stuff' I pass it on... always done that. I'm at the end of my career and my main purpose is to act as a mentor for younger engineers. We have a senior engineer in the office and I went to school with his dad.

No fear of becoming oilfield trash; I know my limitations. Last time I did any indepth review was for thermal siphon piles, a suggestion on how to fix a pipeline that suffered from premafrost thaw. Other than that, I've never worked with pipelines... prior to this posting, I had no idea of what a pig was '(sheltered life); I'd never heard the term.

Dik

RE: Leakproof Pipeline

"I had no idea of what a pig was '(sheltered life); I'd never heard the term."

That's ok, not many do. Just remember it's a name. If anyone EVER tries to tell you it stands for Pipeline Inspection Guage then immediately discount any other pipeline related material to come out of them.

Some environmental engineer somewhere decided to include it in an ESIA or non technical summary and it's just grown a life of its own since then. It doesn't, it never has and it never will.

/rant over

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Leakproof Pipeline

I like the pipeline carrot - bunnies are subterranean critters, aren't they?

RE: Leakproof Pipeline

(OP)
Gator.... came across that, just recently... wascally wabbit... just added... carrots interfere with pigs... only wabbits appreciate them...

Dik

RE: Leakproof Pipeline

2
Pig comes from the tangled ball of chickenwire that they used back in the day. It would squeel it's way down the pipeline.

"He's declaring war on the planet itself."- Vicente Fox

RE: Leakproof Pipeline

(OP)
just grease it a bit so it slides down easier...

Dik

RE: Leakproof Pipeline

It was running in a crude oil pipeline. It don't get more slippy than that.

"He's declaring war on the planet itself."- Vicente Fox

RE: Leakproof Pipeline

(OP)
I guessed that much for the grease... didn't know why it was called a pig... other than the "Pipeline Inspection Gauge" meaning. I'll be aware of those guys...

Dik

RE: Leakproof Pipeline

The origin is not clear - some say it was when they sent actual pigs to eat their way out of medieval sewers, most refer to the squalling of rubber or leather cups and similar "back in the day".

You need to call them "scrapers" in the Middle East just in case anyone takes offence....

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RE: Leakproof Pipeline

(OP)
IR: Not given the time period... even early in the just passed century.

Just finished that article on pigz and had no idea there were so many different types...

Dik

RE: Leakproof Pipeline

Hi Big and Little Inches
Thanks for the information about pipeline life expectancy. I also did not know about UK gas not being odourised in the primary network anymore. How would they find a leak if/when external corrosion starts to be an issue and how big would it need to be before it could be detected - much of the pipeline runs through farm land?
When I started work in 1970 the place I served my time at, (International Combustion in Derby), was very busy with North Sea gas work. Mostly rig leg nodes and gas tees plus pig traps. That type of work was a good fit with their main business as boiler makers

RE: Leakproof Pipeline

The US introduces oderant at the same "town border stations" where gas is metered and sold to local distribution companies. There is no oderant used in cross country USA transmission lines.

The oderizer is mercaptan which contains small amounts of H2S -(forms poisonous, rotten egg smellling and corrosive gas), so H2S is not someting we want in great quantities running around and sticking to the walls of hundreds of thousands of miles of high pressure gas pipelines, so it is left to the last possible point to inject it where the public absolutely needs to be able to detect leaks without the use of complicated equipment that never seems to have its battery charged when you need it.

"He's declaring war on the planet itself."- Vicente Fox

RE: Leakproof Pipeline

The origin is not clear - some say it was when they sent actual pigs to eat their way out of medieval sewers,

Never heard that particularry British twist on the legend, but I like it. Are you sure it wasn't just a pig's bladder running through the drain pipes. Just saying I find it hard to buy the eating their way out bit, given that pigs do have a finite volume to their stomachs nowhere near what I imagine, has the London sewers. It would take one-heck-of-a-lotta pigs, which I'm sure someone in the middle ages would far rather have seen on their dinner table.

"He's declaring war on the planet itself."- Vicente Fox

RE: Leakproof Pipeline

Yeh, I was pretty sceptical as well, but maybe for a small blockage.... pig

The squealing of rubber or leather, especially in gas or air is much more likely.

The other thing about it not being a name but an acronym (it isn't) is that the vast majority of pigs don't inspect anything - they just clean or try and separate.

For separation of products in a pipeline they actually don't do very much at all. I used to work at a multi-product pipeline company who did tests between inserting spheres and pigs to separate batches and no sphere or pig.

They found it made no difference and actually stirred up deposits and basically stopped using them for that purpose. Much of the interface was actually the time taken to open one valve and close the other in the inlet manifold and the mixing of product in the manifold.

Derby Loco - How big - the high pressure system will show up a small hole a lot faster than the low pressure stuff in your street, which is odourised. The change happened in the UK because gas in Europe was never odourised in the high pressure system and when the interconnector between UK and Europe started operation, the UK was exporting gas so they had to change to meet the spec and then had to install hundreds of small odourisation plants at the main offtakes. Helicopter surveys using infrared can find them and the regular ( 5 - 7 year) internal inspections either spot the hole or should identify it before it gets to that point.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

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