Re-Using 8-Year Old Light Fuel Oil Pipeline

Please ensure that the design conditions [pressure, temperature]of the line comply with the intended use.

The line should be examined using a combination of pigs [trust you are familiar with pigging] and this will generally entail:

• a gauge pig [determine if the pigs that follow will fit through the line & check for obstructions],
• cleaning pig [removes debris & improves data collection] &
• intelligent pig [measures wall thickness using magnetic fields].

Underground lines also need to be checked for external coating integrity.

If the line is above ground, external visual inspections & wall thicknesses can also be performed.

Regarding the distance to the transmission lines - cathodic protection specialists should be able to advise you.

Thanks for the answer. However I request clarifications on the followings:

1. Presently at our Plant Location, the pigging facility can not not be arranged instantly. Even if we bring it, it will be a costly affair and will require a justification and acceptance from Management. In light of this should we have to emphasise that with out the pigging services available the 100% Pipeline reliability could not be ascertained or is there any alternate testing and acceptance procedure also, like pressure testing etc.

2. As the underground Fuel pipeline is 8 (Eight Kilometer) Long, hence it is becoming difficult for us to specify that what should the distance between each excavation/digging and how many digging /Excavation should be done and what should be the width of each excavation. Hence kindly specify if there is any code, or please tell us the normal accepted engieering practice used for the following

2.1 If we have to do the excavation/digging to expose underground pipeline

for its external coating integrity then what shall be the specifed distance

between each excavation/digging where we shall expose the pipeline for the

external coatig check. That means total how many locations we have to

dig/excavate for the eight kilometer fuel pipeline.

2.2 What shall be the width of this each of the excavation/digging work for each

location for pipeline extrnal coating integrity check.

Thanking you in anticipation of reply from all the gurus.

Thanks and regards.

VKJ

<1. Presently at our Plant Location, the pigging facility can not not be arranged instantly. Even if we bring it, it will be a costly affair and will require a justification and acceptance from Management.>

Easy. Point out the risks and potential costs of not doing it. Remember Petrobras P-36?

I am assuming that you intend to use this pipe for hydrocarbons of some sort. If so then do as The Hammer suggests, the public get really pi**ed when you pump hydrocarbons under their neighbourhood or into the ground water. Do the intelligent pigging before you decide how much of the pipe to expose for inspection of the coating or wrapping. If the pigging results are perfect then you only need to expose a few places to find out if your coating/wrapping is still in good condition. If the results are bad then you may end up exposing the entire length of pipe for inspection, repair and re-coating. Sounds like a lot of work but it is seriously cheaper than trying to recover spilt hydrocarbons and to rehabilitate the soil, not to mention the lawsuits and bad publicity for your company.

Is each or either end of the pipe exposed? (i.e. I assume the existing pipe end connections are accessible.) What diameter is the pipe?

Yes Sir, each end of the pipe are accessible and could be exposed if required. The dia of pipe is 12".

Thanks

That gives a volume of 584m³, near as damn-it.

If testing for leaks, please use a non-compressible fluid........

Like water......

Do you have access to a substantial water source say a lake or bay within say a half a mile or so? Do you have any MTR's or documentation on the existing pipe? Eight years is not very old. What kind of soil is it buried in? Was there any kind of coating put on the OD of the pipe (i.e. rust protectant)?

HAS THE PIPELINE BEEN EMPTY? I'D FLUSH IT OUT, HYDROSTATICALLY TEST IT AND GO FOR IT. COULD USE EITHER WATER OR AN INERT GAS TO HYDRO IT. MAYBE GET A HOLD OF A, FOR LACK OF KNOWLEDGE ON SPECIFIC EQUIPMENT, BORESCOPE TYPE SET UP THAT YOU CAN LOOK THROUGH PART OF THE PIPE BEFORE PUTTING IT INTO USE ALSO. I'D SPECIFICALLY LOOK AT ANY LOW SPOTS OR SUCH WHERE MOISTURE WOULD HAVE ACCUMULATED.

Dear Sir,

Thanks for the suggestion. However I am not sure that first flushing of an eight kilometer pipe line and then pressuring it for say 2 bar with water and then again draining out water and again re-filling it with LFO is a very comfortable solution.

I am not feeling comortable with this strategy, what is the opinion of other members, kinldy voice your vote for this proposition.

Thanks and regards.

VKJ

Do the right thing. Check it out carefully in spite of the near term costs because it is cheaper in the long run. The recommendations presented to you here on CR4 all sound like prudent things to do. If you did the pigging, saved the test data, made all the engineering logs, and heavens forbid, a disaster still happens, you want to be able to show you used due diligence in re-commissioning the pipeline. If you simply do some quick and dirty checks, the jury will not be very sympathetic. You should be the one to keep management from making stupid mistakes. You cut corners at your own peril.

Depending on what type of external coating was applied, I would try to develop an electro-potential resistance test to verify the integrity of the coating. Again, this would be where a good cathodic protection company could be helpful.

VKJ

I'm a pipeliner although I specialise in pump station design not too much the pipe itself, but I am familiar with the pipeline challenges including sub-sea. Write a brief inspection specification, indicating "Per industry standards and local codes as well as common practices, with a final certificate for fitness of purpose and use" and ask that the procedures be submitted. Hire a pipeline consultant to evaluate the spec and then send this spec to pipeline inspection companies (there are thousands of such companies who know all the codes) and have the consultant evaluate the offers. There is VERY likely a government agency involved that must give you a permit to operate it. Others have all mentioned the right technical solutions. Smart pigging is a must. Low spots cause corrosion from water dropping out. Low velocities cause water to drop out. Erosion, corrosion, earthquakes, coating failures, cathodic protection . . . it is complex. Hydrostatic testing with surfactant is a must and a complex issue requiring a hyrdotest company to do the work. The disposal of the hydrotest test water and surfactant is a HUGE environmental issue. The pumps you plan to use must not be capable of pressures exceeding the maximum allowed working pressure of the pipeline, etc etc etc. Old pipelines may not meat current standards. The original contractor may have paid off inspectors to give them a green tag . . . and you now inherit a poor job . . . . . I've seen it all.

If you are the owner and this is your personal money it is wise to be concerned about the costs but only from a 'go - no go' point of view to energise this pipeline. You don't want to show your cost saving ideas the wife of the man that died at his funeral, or the same to the father of blind children from drinking contaminated water. It is your duty to protect the people and environment.

If this is not your personal money and you are an adviser to your company, then adopt a mindset that this is NOT YOUR MONEY and your job is to point out all risks and a budget to mitigate those risks. Your boss then needs to go get the budget money. I see MANY engineers make poor decisions as if they are spending their own college funds of their children when they don't understand their real job is to prevent risks, not save money. If you are absolutely an expert on the subject, you can then adopt cost saving ideas to accomplish the same goals without risk increase, but this does not seem to be the case here. Uneducated cost saving measures are exponentially dangerous.

Careful. Some countries hold the engineers personally liable. An engineer was recently executed in China for making a bad decision that killed some people.

Fill the pipe with compressed air till you reach 2 bar. Yes a lot of air for 8 km.

Fit a Pressure Gauge at the end. Mark it. Check after every 24 hours. If there is a pressure drop registering in the gauge then obvious- there is a leakage due to pitting. This then is impossible to find down the 8 km length unless, exposed(which it is not) to carry out soap test. You then've no alternate but to discard the whole idea.

If there is no leakage then the pipe is OK. Carry out similar for atleast 5 days to be sure that there is no leakage.

Then flush with the air 5 times. I know lot of air but consider the advantage of recovery of the 8 km length of pipe.

Normally, this is to be done with nitrogen gas but too too costly for 8 km pipe length.

With all due respect to Ducon, please VKJ, don't try this. The pressure will vary tremendously with very slight temperature swings. This is also very dangerous as the compressed partial pressure of oxygen may react with residual fuel oil still present in the abandoned line and make an explosive mixture when charging or discharging the pipe, especially is a rupture is in the area of temperatures above the autoignition temperature of the vapors, including sparking components such as a passing auto. Even with liquid hydro tests we take into account the compressibility of water and slight temperature affects on the hold pressure. Arbitrary pressures for test are equally dangerous as the pipe may not be capable of 2 barg. Smart pigging with material comparison will indicate maximum allowed working pressures and the test pressure is a factor above that per codes. This is a VERY dangerous piece of business best left to professionals with experience. I've been doing pipelines for 25 years and I would not do this myself. I'd still hire it.

Please don't be angry Ducon, as any reply is always appreciated. I feel I must respond for safety reasons.

No I am not angry. My mistake , I was in his place i'd have done it but after going through your reply i really did not take the safety part. Thanks

<Fill the pipe with compressed air > Aaaaaaaaaaaaaaaaaaaaaaaaaaaargh!

Noooooooooooooooooooooooooooooooooooooooo!

Dear All,

Ours is the only Power plant in the Heavy industrial Area.The subject line was handover to us during the Plant handover only three years before. However we have heard that the line was inoperative for the last eight years. However no documents could be traced.

Now after handling over of the Plant presently we are supposed to be the asset owner of the 8 kilometer LFO 12" pipeline. The line is located adjacent to the road the heavy industrial area consisting of Peterochemcial and Power Plant area which As it was abondoned, we have no idea about if there is any or no amount of LFO quantity is present inside the line or not. However we are assuming that the line could be empty

There is also grapevine that this line was abondoned becasue there is high Voltage (138 KV) above ground transmission line running adjacent to it, and also an underground high voltage line is also running parallel to this pipeline.

Now as we do not know about any code which specify abondaning hydrocarbon line for the cause as mentioned above. It will kind of all the learned engineers to enlighten us regarding this.

Is there any body out there who is having any idea regarding the truthfulness or falseness of abondaning the such a long pipeline due to the above specified conditons or that all this is simply not true.

Any answers will be appreciated.

Thanks and regards.

VKJ

I can't speak about codes and whether this is true or false. But I will caution you that pipelines are always being unearthed for repair and having high voltage all around makes me nervous. Here is USA we have all types of technology for detection of buried cables, maps, permits, a requirement that the utility company MUST come make all cables areas before ANY digging . . . even very minor digging around your own home, and still we continue (2 days ago in fact) to have digging equipment operators die from cutting cables and gas lines.