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Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

(OP)
Refer to ASME B31.4 Chapter IX section A423.2 and ASME B31.8 Chapter VIII section A811, is there any reason why plastic pipe with non metallic reinforcement such as RTP pipe is prohibited to be used for offshore liquid pipeline system under ASME B31.4 or for gas transmission line under ASME B31.8?

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

It melts and is a great fuel.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

(OP)
But, why it is allowed for onshore application? If melting is the issue, it shall be prohibited for both onshore and offshore application.

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

I think it is allowed for underground pipelines in B31.8.
As far as I know it is not allowed in liquid pipelines under B31.4
Some pipelines are "flowlines" and are designed to B31.3

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

(OP)
For ASME B31.4, I couldn't find wording that RTP is prohibited for onshore application, even though the RTP is also not listed in the table, but section 423.1 (b) --> Except as otherwise provided for in this Code, materials which do not conform to a listed specification or standard in Table 423.1 may be used provided they conform to a published specification covering chemistry, physical and mechanical properties, method and process of manufacture, heat treatment, and quality control, and otherwise meet the requirements of this Code. Allowable stresses shall be determined in accordance with the applicable allowable stress basis of this Code or a more conservative basis

The above allowing for using of usage of other material.

But what is the reason that make it specific : prohibited for offshore application?

For ASME B31.8, is there any reason it is allowed for buried pipeline, but prohibited for offshore pipeline?

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

Self-evident: When an offshore rig catches fire, you don't have the option of jumping in your pickup and driving away from the danger.

Mike Halloran
Pembroke Pines, FL, USA

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

(OP)
But what is the difference with flexible pipe (API 17 J), and also some sort of rubber line (API 17K) but with steel reinforcement. If fire occur, both will provide similar effect as RTP.

So what specifically prohibit Pipe with "non metallic reinforcement" type is prohibited?

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

Basically B31.4 and 8 pipelines are ment to be BURIED. That's the general idea. Miniscule to no chance they will catch fire being underground. The last thing you need anywhere for that matter is the pipe catching fire. I wouldn't use any plastic pipe anywhere that would catch fire to pipe anything except water.

Non-metallic reinforced, plastic pipe loses strength over time.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

Almost all plastics are permeable to hydrocarbons to some extent, especially the lower molecular weight fractions, so the area surrounding the pipe might build up hydrocarbons to a level that provides an explosion risk. This is why you should never sore fuel in a plastic container in a confined space unless the plastic container has been treated with fluorine gas to chemically seal the pores.

Also as already mentioned plastics melt at relatively low temperatures and most burn well.

Rubber is also permeable to hydrocarbons.

Steel braiding reinforces pipe from stretching to much and bursting under load, but does not protect all that well to crushing and does not offer any barrier to permeation of the hydrocarbons through the pipe.

Regards
Pat
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RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

What nonsense. The risk of a fire in non-metallic piping is very similar to the risk in metallic piping. Any time there is a code that excludes (or even prohibits) reinforced composite piping it is generally because the code has not been updated. FlexSteel was developed for offshore applications and is specifically reinforced against anchor-drags (the main failure mode of subsea pipeworks). There are thousands of miles of this stuff in the ocean in both gas, oil, and produced water service as we speak. If a code (and I don't use B31.4 so I can't speak to it directly, but B31.8 has good things to say about spoolable composites) explicitly prohibits it, I couldn't tell you what they were thinking, or when that "thought process" occurred.

David Simpson, PE
MuleShoe Engineering

"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

In any case you may need to comply with API RP14E as well.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

The scope of API RP 15S states "for offshore use, additional requirements may apply." It suggests that applying RTP pipe offshore hasn't got round to being thought of seriously just yet. It takes a while, and a number of joint industry projects to get over the 'it's not in the code' hurdle.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

All answers are personal opinions only and are in no way connected with any employer.

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

Do you think BP will do it?

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

Funny question. The original development of spoolable composite pipe got seed money from a project managed by George King, an Amoco Research Center employee. George eventually retired from BP, but he was instrumental in the early deployment of this pipe including to Amoco's facilities offshore. The new BP might not take the risk, but the old BP was a leader in that technology.

David Simpson, PE
MuleShoe Engineering

"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

(OP)
API 15S was a JIP output. However it is not a spec, just recommended practice. With recent development in composite pipe, RTP is not just kevlar reinforced thermoplastic, but also glas fibre, combined glas - kevlar reinforcement, bonded and unbonded structure. They are trying hard to fit in API 17B, 17J & K. I know the limitation to temperature, long term strength, non plastis burst, permeation issue, etc. But still cannot understand why onshore application is allowed, but offshore is explicitly prohibited.
Agree with SJones, for offshore use, additional requirement may apply. In my thought are collapse and buckle, tension, torsion, on bottom stability, installation, external impact, etc, similar to steel pipe.
However, the main code, B31.4&8 is explicitly prohibit it for use in offshore.

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

Not ready for prime time. There are still many unanswered questions concerning long term performance issues of non-metallic products.

There is only one instance that I know about where Reinforced Thermo-Plastic products are PROPOSED TO BE tested in a regulated environment, actually in a Class 4 location if you can believe it, outside of totally UN-regulated gathering systems. Offshore is regulated territory. Highly regulated. It will be awhile, if ever.

zdas, "the old BP was a leader in that technology"; risk management technology I presume.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

Fiberspar's web page used to have a speedometer looking thing that said 8 million miles installed and counting. FlexSteel advertises "over a million miles installed". Others are similar. This stuff is so good that it will not be held back by idiots on quasi-regulatory committees of ASME, API, or ISO.

BigInch, I'm ignoring the jape.

David Simpson, PE
MuleShoe Engineering

"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

Nor by idiots offshore either?
I actually think that the stuff looks very promising, but no way I would use it in any location that could be exposed to fire. Don't make sense to risk a nice big money-making pipeline just for saving a few thousand dollars.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

I use it everywhere that they have a size the fits the application and have for 10 years. Today 6-inch products are widely available I and I wish the spools were longer, but I still use it. I've never been terribly concerned about fire on pipelines--mostly I bury them and dirt don't burn. Seriously, I have never seen a pooling liquid fire outside of a plant fence. Every fire I've investigated has been a jet fire that cut through steel pipe as fast as it would have cut through plastic. The fire thing really is a non-issue.

David Simpson, PE
MuleShoe Engineering

"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

While not diminishing any claimed utility of the same nor intending to in any fashion pick sides in this educational debate, the FlexSteel pipe as detailed at e.g.
http://www.flexsteelpipe.com/products/pipe-specifi... does appear some limited as far as pipe size, tensile/pulling load and maximum water depth capabilities (that I would think could be judged important in much "offshore" work). Also, it also looks like the "FiberSpar" pipe may still have the (McDonalds-style?) lifetime aggregate production sign/banner still up and running now at the website http://www.fiberspar.com/# , though it appears to date with a magnitude "50,000,000" FEET displayed (scrolling, fifth balloon in banner) .
While I guess this amount of pipe is meant to sound like a lot, maybe (with less than 10,000 miles total?) it may not really be a whole lot yet in the whole energy pipe market/scheme of things.

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

One should perhaps consult ISO 14692 Petroleum and natural gas industries —
Glass-reinforced plastics (GRP) piping. Or Det Norske standards such as http://www.google.com.au/#hl=en&tbo=d&scli...

“The beautiful thing about learning is that no one can take it away from you.”
---B.B. King
http://waterhammer.hopout.com.au/

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

(OP)
Please be focus on "thermoplastic" pipe with non meyallic reinforcement, called RTP.
Flexsteel product is flexible pipe with steel reinforcement, and fiberspar or any GRP product is thermoset pipe. Both ar not my interest in this discussion.

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

RTP is not a term I am familiar with. I will stop trying to contribute to the discussion.

David Simpson, PE
MuleShoe Engineering

"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

RTP is reinforced thermoplastic, like polyethylene, polypropylene, polycarbonate, nylon acetal ABS and some polyesters and some polyurethanes. There are a lot to many to list. The reinforcement is most often short glass fibres, but can be long glass via a quite expensive process and can be many other fibre types like carbon, aramid, wollastonite or even stainless steel.

Fiberglas is reinforced thermoset plastic like two pot polyesters or epoxy or urea, melamine or phenol formaldehydes. Rubber is also mostly a thermoset unless otherwise specified.

Regards
Pat
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RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

I've called that FRP (fibre reinforced plastic) for 25 years. Guess I was wrong.

David Simpson, PE
MuleShoe Engineering

"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

Amending Codes, especially when the amendment is perceived as "loosening" restrictions, is quite difficult. Code participants are much more willing to increase restictions when evidence warrants. Code participants may have rooted opinions, often justified; adhearance to the status quo is often more preferable. There may also be legal (perceived liability) issues when Codes are adopted by Jurisdictions should catastrophic accidents occur.

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

You can have a look at what Airborne are doing with RTP pipes.
For some short words on their qualification approach check out http://www.airborneinternational.com/index.php?opt...
"Because no specific (ISO or API) standards exist for composite pipe systems, the approach is followed- as described by the DNV Recommended Practice for New Technologies, DNV RP-A203, and DNV OS C501 for designing in composite materials."
They are putting a lot of money into their second manufacturing facility to substantially increase their capacity.

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

David

Technically your not wrong. It is fibre reinforced plastic, but the industry in its ignorance has always reserved FRP for traditional fiberglass of very long glass fibres layed up with a thermosetting resin, most often two pot polyesters, but also epoxy or others.

Short fibre reinforced, like 1mm long or less in a thermoplastic resin is called RTP or just glass filled nylon or whatever resin. Different people tend to use different terminology ranging between glass fibre reinforced to glass fibre filled to glass filled.

Other fibres like carbon and mineral fibres further confused terminology as does different polyesters simple being referred to as polyester and fillers other than fibre being used.

I gave up years ago trying to introduce logic and accuracy to it.

Regards
Pat
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RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

Huhhm, modern “codes”… Back in an era when I suspect metals e.g. iron were at least as valuable or precious as they are now, and buildings/houses were largely non-metallic logs or wood, I believe e.g. one quite bright American wrote about 260 years ago (in Poor Richard’s Almanac) that one should use some of it quite strategically,

“How to secure Houses, &c. from LIGHTNING”:
“It has pleased God in his Goodness to Mankind, at length to discover to them the Means of securing their Habitations and other Buildings from Mischief by Thunder and Lightning. The Method is this: Provide a small Iron Rod (it may be made of the Rod-iron used by the Nailers) but of such a Length, that one End being three or four Feet in the moist Ground, the other may be six or eight Feet above the highest Part of the Building. To the upper End of the Rod fasten about a Foot of Brass Wire, the Size of a common Knitting-needle, sharpened to a fine Point; the Rod may be secured to the House by a few small Staples. If the House or Barn be long, there may be a Rod and Point at each End, and a middling Wire along the Ridge from one to the other. A House thus furnished will not be damaged by Lightning, it being attracted by the Points, and passing thro the Metal into the Ground without hurting any Thing. Vessels also, having a sharp pointed Rod fix'd on the Top of their Masts, with a Wire from the Foot of the Rod reaching down, round one of the Shrouds, to the Water, will not be hurt by Lightning.”

While I guess even our precocious Ben Franklin may not have precisely understood then the integral calculus/electrical engineering involved in structural damage to building materials by lightning (i.e. by deposition of thermal energy, ∫ i2Rdt ), he did understand lightning could and occasionally would hit (or ignite or blow holes in!) virtually anything/material, and he eventually also knew as long as you didn’t have “ahold of” same at the time it would do less damage when it could run down his conductive invention. In the centuries since (and whether or not it has been understood or appreciated by those of us with a great many IQ points less than ol’ Ben), all manner of structures, be they homes, factories, refineries, platforms, or whatever have of course subsequently been provided with sorts of metal skeletons or exo-skeletons in the form of metal eaves, vents and downspouts, metal beams or other building materials, or if not anything else at least sturdy metal water and gas pipes going to many rooms (with same often transitioning far into ground) and indeed copper wiring if not specific lightning rods and grounds etc. I guess this traditional infrastructure has sort of kept us in general pretty safe for a very long time, regardless of exactly how it was done, who did it, or whether it was exactly “up to/per” any code. I think some standards e.g. API RP 2003 -- Protection Against Ignitions Arising out of Static, Lightning, and Stray Currents to their credit at least up until a very few years ago if not currently contained some guidance statements e.g. to effect, “Metallic tanks, equipment, and structures commonly found in the petroleum industry that are in direct contact with the ground (i.e., no nonconducting membranes) have proved to be sufficiently well grounded to provide for safe propagation to ground of lightning strokes…” and at least with regard to tanks, “It is not recommended to store flammable liquids in nonconductive (e.g., plastic, fiberglass) aboveground tanks.”

Now, some modern science and “technology” thinks they have a better idea, i.e. go increasingly toward such things as non or less-metallic “flexible” pipes or composites, that the pipe pushers or developers claim can be installed at less cost, will do the job, or may even have other advantages over sturdy and more conductive and more heat-resistant metals - “Plastics my boy, plastics”! Now while I think most contemporary specifying Engineers (and Regulators) understand that plastic pipes are not really near as strong as traditional metal pipes, they may not be aware of many less obvious shortcomings and they can additionally be sorely tempted (or blinded?) by the lure of lower material prices, alleged cheap installation costs or other claimed advantages, and/or other pressures so to speak (and many succumb).

While it is bu tone of many issues, since ancient times lightning has traditionally been considered an “Act of God” (or hurled down from the hand of gods?), it appears vulnerability to same can be increased by some choices of Man. You will notice that very quickly if you e.g. do a Google search with the keywords, “lightning strikes plastic gas pipes”, that many unfortunate (and surely unintended?) events over the last few years e.g. were really foretold long ago, e.g. in the article also near a quarter century ago at http://www.jlconline.com/Images/Lightning%20Protec..., “Whenever you substitute plastic piping for metal or use electronic
devices, you increase a building’s vulnerability to lightning currents.” And then there are also some rather non-obvious static electricity effects with non-metallic gas and fuel pipes and containers (not discussed by this particular author). I guess if one is dead set on installing mostly non-metallic pipes etc. as opposed to legacy metals, it seems a complicated business to protect same and one might want to find an overall designer smart enough, and a suitably trained installer also smart and conscientious/honest enough, to design, build, and stand behind a reasonably safe outcome, and be sure to figure all costs of same in to any material comparisons, lest this “strike” (so to speak) close to home. That apparently been some difficult to find/obtain in at least many areas of at least 12 states. Everyone have a good weekend.

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

Good grief. That was a hell of a novel to simply say substituting plastics might increase damage from a lightning strike.

Even then you forgot to mention if the installation is indeed subject to risk of a lightning strike, as I have yet to witness the lightning strike a cable laid deep on the ocean floor.

I am aware that lightning strikes can damage cables buried in the ground and in fact high dielectric reinforcement of optical fibre cables can in fact reduce risk of damage from lightning.

I certainly know that at least one manufacture of aramid fibre has a technical bulletin discussing the concequences of lightning strike when aramid replaces steel reinforcement.

I also know aramid fibre reinforcment has been successfully used in applications where steel failed due to lack of strength.

Regards
Pat
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RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

Explosive decompression is another "worry". High pressure gas dissolved in the plastic can be explosively released from the wall if the pipe is rapidly depressurized.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

I've seen explosive decompression, but only in a phase change scenario (e.g., CO2 at 80F and 10,000 psig is dense phase and that is what absorbs into the plastics--when you depressurize the line the dissolved dense phase stuff explosively becomes gas and shreds the plastic). I have never seen it in FRP, and I haven't used RTP.

David Simpson, PE
MuleShoe Engineering

"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

I believe it is feasible with either material under certain conditions.

Also plastics have a very narrow good temperature window for use compared to metals.

Regards
Pat
See FAQ731-376: Eng-Tips.com Forum Policies for tips on use of eng-tips by professional engineers &
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RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

(OP)
To BigInch,

Is there any records/statistic of failure of RTP/FRP/GRP for onshore application due to explosive decompression?

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

As it is prohibited, I would assume offshore records are nonexistant. There may be some onshore, or perhaps some test data. All I know is that it is believed to be susceptible, since gas has supuposedly permeated into the reinforcement layers. Its history of use onshore is not long either.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

hallo guys,

im new kin in the block...just wonder if any of you have experience in RTP subsea installation. Maybe you can share some as im going to involve in mentioned job. Fyi, the job concept is insertion whereby originally 12" pipe of crude will be decomm and RTP of 3" will be insert into the pipe.

Looking forward your expertise.

RE: Prohibition of Reinforced Thermoplastic Pipe for Offshore Pipeline (Liquid & Gas Hydrocarbon)

hathib, start a new thread.
You might want to give a much better explanation of what you're trying to do too.

Independent events are seldomly independent.

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