Hi Geoff
until relatively recently, my experience and recommendations were similar to
yours.
However it is undeniable that larger quantities of oil products are stored
in PE containers of various compositions and sizes. I'm just trying to find
out the size of the envelope.
The same applies for the PE pipeline. It is used for transferring marine gas
oil from a seagoing tanker to a port facility on a small island. The
pipeline is floated out to the ship and connected using flexible hose at
both ends. The permanent shore line remains full at all times and is denso
wrapped steel. When fuel transfer is finished, the PE line is fished out of
the drink and stored empty.
When this was first proposed, I objected on similar grounds to yours.
However it was pointed out to me that it (i.e. oil transfer in PE) was
already being done successfully. So we carried out a number of weight gain
lab tests, carried out a number of tensile/extensibility tests until I was
satisfied the risk of failure was manageable. This was about 15 years ago
and I no longer have records of the tests.
The line still works fine though. I shouldnt think we will find any standard
covering short term exposure of PE to hydrocarbons, although the information
sent by Randy is very encouraging.
Cheers
Steve
>From: Geoff Stone DD&D Australia <blenrayaust@yahoo.co.uk>
>Reply-To: PipingDesign@yahoogroups.com
>To: PipingDesign@yahoogroups.com
>Subject: Re: [PipingDesign] Re: Polyethylene chemical resistance for medium
>term liquid hydrocarbon duty
>Date: Sat, 24 Jun 2006 00:25:38 +0000 (GMT)
>
>Hi Steve,
>
>I have about twenty plastic text books at my disposal but am yet to find
>one that suggests that PE should be used for storage of large quantities of
>hydrocarbons. Sure your PET bottle with metho is OK but bulk storage? I
>will keep looking.
>
>What Code was used to design the PE pipeline for marine storage? I am
>interested to know if it comes up again.
>
>Of course polyamides and PE are used frequently here for natural gas
>reticulation but at low pressure.
>
>regards
>
>Geoff
>
>Design Detail and Development (a division of Blenray Pty Ltd) URL
>www.waterhammer.bigblog.com.au
>Mail Address PO Box 1351 Castle Hill NSW 1765 Australia Tel Mob 0402 35
>2313 Office 02 8850 2313 AH 02 8850 2324
>We specialise in pipe network and waterhammer analysis, pipe stress
>analysis, the design of buried pipelines and thermoplastic pipe systems.
>
>
>
>
>
>----- Original Message ----
>From: Steve McKenzie <gyro-@hotmail.com>
>To: PipingDesign@yahoogroups.com
>Sent: Friday, June 23, 2006 8:11:38 PM
>Subject: [PipingDesign] Re: Polyethylene chemical resistance for medium
>term liquid hydrocarbon duty
>
>
>Hi Geoff
>Fire is a separate issue and not relevant in this case.
>PE is routinely used for storing gasoline; am told the gas tank in
>your Ford Falcons is probably PE. I have used HDPE pipe for unloading
>marine gas oil from oil tanker ships over the last 10 or so years.
>Not all chemical resistance charts agree about benzene. I am
>currently storing a small amount of product with no apparent damage -
>yet. And then again Im not sure if all PEs are the same with regard
>to chemical resistance. Certainly, I know that the fuel tank on my
>Solex moped looked like PE, but sure as hell wouldnt weld (after I
>fell off and broke it). Suspect its a something like a PE/nylon
>copolymer.
>Thanks for your comments; appreciate you letting me know if you find
>anything else.
>
>Cheers
>
>Steve
>
>--- In PipingDesign@ yahoogroups. com, Geoff Stone DD&D Australia
><blenrayaust@ ...> wrote:
> >
> > Steve,
> >
> > PE is not suitable for hydrocarbons storage. Sweklling does occur.
>But the big problem is fire. In the event of a fire the tank will
>melt and the contents spill and fuel the fire.
> >
> > Cross linked PE does not apply to PE 80 or PE100.
> >
> > Geoff
> >
> > Design Detail and Development (a division of Blenray Pty Ltd) URL
>www.waterhammer. bigblog.com. au
> > Mail Address PO Box 1351 Castle Hill NSW 1765 Australia Tel Mob
>0402 35 2313 Office 02 8850 2313 AH 02 8850 2324
> > We specialise in pipe network and waterhammer analysis, pipe stress
>analysis, the design of buried pipelines and thermoplastic pipe
>systems.
> >
> >
> >
> >
> >
> > ----- Original Message ----
> > From: Steve McKenzie <gyro-@hotmail. com>
> > To: PipingDesign@ yahoogroups. com
> > Sent: Thursday, June 22, 2006 7:19:30 PM
> > Subject: [PipingDesign] Polyethylene chemical resistance for medium
>term liquid hydrocarbon duty
> >
> >
> >
> > L&G
> >
> > A client is carrying out some temporary works requiring storage of
> > oil refinery product including gasoline, benzene, jet fuel, diesel,
> > kerosene and probably a couple I have forgotten. He has already
> > purchased some PE tanks, prior to finalising what would be stored
>in
> > them. Before I condemn them, I would like to be absolutely sure
>they
> > are unsuitable for the duty. The reason for this is that they are
> > already purchased, the design life will only be of the order of 3
> > years, and the tanks walls appear fairly thick.
> > So I am looking for some method of derating the design stresses to
> > compensate for the chemical attack plus a method of uprating the
> > design stress to allow for the relatively short design life. I have
> > some information on the latter, but nothing on the former. Any
>leads
> > would be welcome.
> >
> > Second I have been informed that "linear polyethylene" has inferior
> > hydrocarbon resistance than "crosslinked polyethylene" . Can anyone
> > tell me what the linear and crosslinked terms mean in relation to
> > available PE products (eg PE80, PE100, HDPE,MDPE etc), and the
> > nomenclature more commonly used in piping design.
> >
> > I havent done a web search, but was hoping someone might have an
>off-
> > the-cuff answer. If not, I can do the searching myself.
> >
> > Thanks
> >
> > Steve
> >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>
>
>[Non-text portions of this message have been removed]
>
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