HDPE Standards in Australia 3

[zdas04]

I finished my 6-day class in Brisbane yesterday and one of the students was adamant that the pressure limitations that I listed in the course (which were extracted from ASME B31.8) were outrageously low and that her company uses the Queensland Standards to calculate pressure. I looked for the Queensland standards this morning and found several that may be appropriate, but they all require a purchase of the standard. I have no problem purchasing the standard (cost of doing business), but I don't want to purchase 6 or 7 of them before I find the one I'm looking for.

Can anyone point me to the Australian and or Queensland standard that would give max pressure and max temperature calculations for HDPE in natural gas and two phase natural gas/water systems?

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.
The plural of anecdote is not "data"

 

[BigInch]

I only have a draft copy of AS 2885 and it does not appear to specifically preapprove PE piping material specs by name, however it allows other nonlisted materials to be used with appropriate qualification.

AS 4130 Polyethylene (PE) Pipes for Pressure Applications
------------------
But why worry about it, presuming that you didn't go there to teach them their codes that you don't even have a copy of. Just tell them, "Hey ya, if that's what your code allows, go with it", and let them use what they want. Unless you're going to stay awhile, of course.

Independent events are seldomly independent.

 

[austsa]

AS4130 PE PIPES FOR PRESSURE APPLICATIONS is the key Australian standard. This standard details pipe sizes, SDRs, pressure ratings, colour, etc. As an aside, AS4131 deals with PE compounds for pressure applications.
If you list the 6 or 7 standards, I may be able to shed more light on them.

 

[stanier]

AS 2033 Installation of PE
WSA 01 Water Services Industry Association Standard for PE
AS 4131 covers the compunds for PE pipe
AS 2566 Buried Pipeline Design and Installation

http://www.hydrogold.com.au/jgp/pdf/lib.vinidex.pe_pipe.pdf

http://www.vinidex.com.au/page/gas__coal_seam_gas.html

http://www.iplex.com.au/iplex.php?page=lib&lib=1

At the end of the day these standards are vouluntary and have no standing unless enshrined in law or contract.

“The beautiful thing about learning is that no one can take it away from you.”
---B.B. King

http://waterhammer.hopout.com.au/

 

[zdas04]

I bought AS/NZS 4130 and best I can tell new gas gathering systems would be Series 2 (which is "fuel gas", but includes natural gas, LNG, LPG, etc). The only pressure calculations are in Appendix B and that is for Series 1. I think this was a waste of $90.

I know I don't want Water Services Industry documents. I can't tell from the other documents in Stainer's list if they would have the derates that ASME B31.8 has. From the links, one would think that SDR 13.6 should be good to 10 bar (145 psig), but both ISO and ASME say that regardless of the calculations you do the MAWP must be less than 100 psig (690 kPa, 6.9 bar).

Any other ideas?

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.
The plural of anecdote is not "data"

 

[zdas04]

I found AS 2885 Part 1 which has the misleading title "Pipelines--Gas and Liquids Petroleum, Part 1: Design and Construction" which I thought might have the pressure design calcs. Oh foolish me. Now I'm nearly $500 into this search.

I just want to know how ("why" would be nice, but I'll settle for "how" right now) an Engineer in Queensland would put 10 barg (145 psig) MAWP on an SDR 13.5 pipe at 40C (104 F) and then argue that they have no obligation to follow ASME B31.8 limitation that un-reinforced HDPE in natural gas service cannot have an MAWP greater than 100 psig (regardless of SDR Number) or operate above 35C.

Mostly they took exception to my assertion that downstream of a compressor station with a 20C approach to ambient cooler in the interior of Queensland, they had to use 62C (144F) as their design temperature, and per ASME B31.8 that gives you an MAWP of 20 psig (138 kPa), not 145 psig. It got somewhat heated.

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.
The plural of anecdote is not "data"

 

[BigInch]

ASME the "A" is "American" not "Australian". Just about everybody outside the US has no legal obligation to follow ASMEs. In a number of countries, ASME codes are not conservative enough for them, in others, ASMEs are too conservative for them. It may have something to do with the rabbits and kangaroo count/hectare, or whatever; it doesn't matter. As of today, I've been working outside the US for 27 years and the best advice I can give you is "When in Rome, do as the Roman does." And, if it stinks, hold your nose.

Independent events are seldomly independent.

 

[stanier]

Extract from AS 4130 PE for Pressure Appications
The objective of this document is to provide a standard specification for manufacturers and
purchasers of polyethylene pipes used for pressure applications.
This revision is based largely on the latest ISO documents. The notable exception is the
inclusion of Series 3 gas pipes, which are included for reasons of compatibility with
existing systems. Series 2 gas pipe dimensions are such as to ensure compatibility with
existing systems that conform to the ISO 11922-1 size series. Series 1 pressure pipes are for
general pressure applications and are compatible with the ISO 11922-1 size series
dimensions.

1.1 Scope
This Standard specifies requirements for polyethylene pipes for the conveyance of fluids
under pressure. Such fluids include, but are not restricted to, water, wastewater, slurries,
compressed air, and fuel gas. Fuel gas includes natural gas, liquefied petroleum gas (LPG)
in the vapour phase and LPG/air mixtures.

The design factors to be applied for gas applications are found in AS 4645 part 3 Gas Distribution Networks Plastic Pipe Appendix B. AS 4130 defines the PN (pressure number in bars) This is derated based on service factors and temperature. Temperature derating is generally defined by the manufacturer based on the polymer and manufacturing process.

PIPA technical guidelines are used for derating of PE.

http://www.pipa.com.au/images/pdf/pop013.pdf

This gives a derated pressure of 99barg. The reason ASME B31.8 isnt followed here is because we are not American!!!!!!!!!!! ASME stadards are not enshrined in law when an Australian standard exists. USA standards are considered old hat and conservative. We tend to follow ISO and E practice more. Our pressure piping code is not based on ASME B31.3 but a British Standard. It defers to the ASME codes as most refineries were built to them by USA companies many moons ago.


PE100 SDR 13.6 is rated PN12.5 at 20C by AS 4130 Table 1. ASME PE is to 3408 I seem to recall and is different to PE100.

“The beautiful thing about learning is that no one can take it away from you.”
---B.B. King

http://waterhammer.hopout.com.au/

 

[zdas04]

Stainer,
That is more exclamation points than I've used on this site all together in the 11 years I've been here. I guess I hit a nerve, but I don't know why?

The PIPA link was useful in that it says that (emphasis theirs)

The rerating factors in this guideline are expressed in metre head of water and are not for use with compressed air or gas applications

(and just for reference it doesn't say 99 barg anywhere in the document) That quote makes me think that when AS/NZS4130 says "fuel gas" they mean "fuel gas" and it excludes gathering systems altogether. It doesn't define terms very well.

It isn't America, but the list of codes included explicitly by reference in the Australian company's design document for a project in Queensland includes ASME B31.3 and ASME B31.8. Since none of the AUS documents seem to include an explicit means to calculate pressure other than relying on the manufacturer's (assumed to be biased) calculations, I guess the ASME codes control.

PE100 is a material called PE4130. PE80 is a material called PE3408. The project was PE3408. Both of the numbers are related to the HDB of the pipe material. PE 4130 has a long term Hydraulic Design Basis of 2000 psig and a design factor of 0.5--hence the PE 100 for 1000 psig. 3408 has a HDB of 1600 and a design basis of 0.5--hence the PE80 for 800 psig. I guess all of the American crap has not been exorcised here yet. PE80 in SDR13.6 within AS/NZS4130 is rated at 10 barg at 20C for fuel gas.

This is all well and good. I have no problem using the proper codes for where the pipe is at. The problem I have is that none of the codes I've purchased today tell me the techniques to use to operate the pipe at 62C. A couple of trade associations I found would say 20 psig or 138 kPag. ASME and ISO would say that you can't do it at all. The AS seems to be silent on the subject (except for the introduction to AS/NZS 4130 that says you can only use it from -10C to 35C, but then never says that in the body of the document).

BigInch,
At least part of my work has been outside the U.S. since 1980. I know exactly what you mean, and no one ever wants to hear "that is not the way we do it in the U.S", and I never would say that. I look at the codes and standards that a company wants to use and help them make appropriate decisions within the limitations of those codes and standards. I've made a pretty good income from never saying the U.S. is right and [Australia for example] is wrong. I don't say it because I don't think it.

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.
The plural of anecdote is not "data"

 

[Kiwi2671]

zdas04,
My sincere apologies for hijacking your post but wanted to respond to Staniers comments.

Stanier,
Your comment that the Australian pressure piping code - AS 4041 is not based on ASME is a bit strange as the Foreword of AS 4041 states ASME B31.1 & B31.3 are a major source of material.

"This Standard makes use of current American and British Standards such as
ANSI/ASME B31.3, Process piping, and BS 806, Specification for the design and
construction of ferrous piping installations for and in connection with land boilers, as well as Australian Standards. This has been done where practicable to align with international practices to provide flexibility in design and to enable current proven computer programs for either of the above Standards to be used to satisfy the design requirements of this Standard (see Clause 1.6).

Comparison of this Standard with ANSI/ASME B31.1, Power piping and
ANSI/ASME B31.3 shows that for the same pressure and application, piping to this
Standard may be thinner than piping to the two American Standards at low to medium
temperatures. These two American Standards have been consulted as a major source of material, but preference has been given to BS 806 for ferrous materials. Certain subject matter either unique to BS 806 or too complex to modify has been copied direct and the source acknowledged".

What relevance does BS 806 which deals with boilers have with petroleum piping or LNG piping or petrochemical piping ? - Basically nothing.
Instead of utilising perfectly good American or British codes that have been successfully used for years they have decided to write a totally new code by taking bits of this code and bits of that code and ending up with a shambles.

Take ASME IX and the old BS/EN 288 Part 3 for qualification of Welding Procedures as an example or ASME IX and BS/EN 287 Part 1 for Welder qualification - totally different requirements.
Even though these three codes are not mentioned in the Foreword they have clearly been used for the basis of the writing of AS 4041.

If talking pipelines, B31.8 was mentioned. I have never heard of this used in Australia but there are thousands of kilometres of piping laid to API 1104 - probably the same for AS 2885 and yet they are totally different codes with different allowances and different acceptance criterias.
Wonder if the oil or gas knows the difference ?

I understand your comment about the American involvement "many moons ago" but there would be over US$50 billion of construction work underway in Australia now and at least 95% will be constructed to American codes/standards.
Tried thinking of one major Australian oil and gas company I had worked for (I think BHP Billiton is all offshore)and all I came up with was Santos and Origin Energy and both of them use ASME B31.3 exclusively,
Regards,
Kiwi

 

[stanier]

Zds04,

The term fuel gas is defined as including natural gas in the standard.

PE is used for coal seam gas gathering systems almost universally. I guess the 62C comes from the bore water. Generally the piping up to the water separator would be in a super duplex stainless steel , ABS
or GRP. I would not be using PE at this temperature.

“The beautiful thing about learning is that no one can take it away from you.”
---B.B. King

http://waterhammer.hopout.com.au/

 

[zdas04]

I saw that natural gas was included in the list of "fuel gas", but the more I read, the more I'm thinking that it is specific to fuel gas and does not include gathering or distribution piping. The standard is really vague on that issue. All of the reference material that I can find seems to be limited to water. I'm reaching the end of the time I have available to research this and don't feel that I'm approaching the final word.

I feel confident saying that PN10 refers to a 10 barg MAWP for water at 20C. The material I normally work with sets the MAWP of SDR 13.5 in water at 73F (22C) at 128 psig (8.9 barg), lowering the temp to 20C makes a 10 barg MAWP for water quite understandable. But then the material that I normally use adds derates for hydrocarbons, derates for gas, and derates for elevated temperature. Those values are what I cannot find for Australia in general or Queensland in particular.

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.
The plural of anecdote is not "data"

 

[BigInch]

David, from what I've found here, it indicates that similar methods should be used in Australia, at least for temperature derating. There were a few documents pretaining to compressed air piping that might address "gas" derating, or rather deratings when used for compressed air. I don't know.

http://www.pipa.com.au/

http://www.pipa.com.au/index.php?option=com_content&view=article&id=99&Itemid=81

"The Maximum Allowable Operating Pressure (MAOP) of a polyethylene (PE) pipe
system is influenced by the temperature of the pipe wall. The nominal pressure
rating (PN) assigned to an AS/NZS 4130 PE pipe equates to performance at 20°C,
i.e. a PN16 pipe is capable of withstanding a MAOP of 160m head (or 1.6MPa or 16
bar pressure) when operating continuously at 20°C. However, as the temperature of
the pipe wall increases, the MAOP of the pipe is reduced progressively – in other
words the pipe system is re-rated with increasing temperature.
The guidance provided in this document

http://www.pipa.com.au/images/pdf/POP013.pdf

is based on typical PE compounds used in
Australia and New Zealand to manufacture AS/NZS 4130 PE pipe and listed in PIPA
Guideline POP004, Polyethylene Pipe Compounds. Where appropriate, specific
advice should be obtained from the pipe manufacturer.
These guidelines apply to pipe used for the conveyance of water. Where other
incompressible fluids are being considered, the designer must assess the affect of
the fluid on the PE pipe system at the operating temperature.

"OTHER DOCUMENTS"

http://www.pipa.com.au/index.php?option=com_content&view=article&id=205&Itemid=97

TEMPERATURE DERATING

http://www.pipa.com.au/images/pdf/Techpubs/tn003.pdf

Polyethylene - the Optimum Gas Material?

http://www.pipa.com.au/images/pdf/Techpubs/tn004.pdf

For further information please contact us at plasticspipe@pipa.com.au
(maybe they have no telephones??)



Independent events are seldomly independent.

 

[stanier]

The standard AS 4645 quoted gives the design factors for gas and location. See extract below.

“The beautiful thing about learning is that no one can take it away from you.”
---B.B. King

http://waterhammer.hopout.com.au/

 

[BigInch]

So (not seeing the rest of the story) I guess the Design Factors are divisors when determining allowable pressure, or multipliers when determining wall thickness.

Independent events are seldomly independent.

 

[zdas04]

BigInch,
The rest of the story is (I bought AS/NZS 4564, that is the one I needed from the start, but one of the tables I needed was in AS/NZS 4130):

MAOP less than or equal to 2 * MRS * T(min) / C / (D(min) - T(min)

With MRS = 8 MPa for PE 3408
D(min) = 109.2 mm for DN 110
T(min) = 8.1 mm for DN 110

So in NG service, Temp above 30C, Ploughed in, Open field, C=2.574 so MAOP for DN 110 must be less than 498 kPag or 72 psig. Higher than I get, but lower than the girl who took exception gets. The big difference is that the AS technique defines a different MAOP for each size pipe and the ASME method defines it for each SDR. Not a huge difference.

Thank you stainer for posting that extract it led me to exactly where I needed to go.



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.
The plural of anecdote is not "data"

 

[BigInch]

Ya. He needs a star for that. I almost gave him one before, so I think I'll do it now before I forget again.

Independent events are seldomly independent.

 

[zdas04]

If anyone is interested in the results of this exercise see the attached

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.
The plural of anecdote is not "data"

 

[stanier]

David,

A couple of points. HDPE is High Density Polyethylene. PE 80B and PE 100 are both medium density polyethylenes. PE80C is HDPE. Pedantic I know but it does cause problems in contracts because of contra preferentum. HDPE is not generally available in Australia. Many engineers refer to black PE as HDPE but they are wrong. A bit mike calling up ANSI 150lb flanges whereas it should be ASME Flange Class 150.

PE 80B is no longer common place and I am amazed this is what is specified in your project. Most manufacturers have standardised on PE 100. The wall thickness is lower for the same PN and thus less resin kg/m pipe and energy kW/m of pipe is used in the pie's manufacture. Hence less money invested in stored product.

PE manufacture is a cut throat business. If the major manufacturers can extrude one size all day long with start up and shut down tey do. They also use sophisticated instrumentation to control wall thickness to within a nat's hair of the minimum allowable wall thick under AS 4130. So there is no added safety factor.

As for Australian standards there still exists a fortress Australia mentality here. Even morphed ISO standards have an extra appendix ( Appendix Z). This is ostensibly to add local conditions to the standard. In effect it limits the import of product as such would not comply with what is in this appendix. Australian standards are dominated by manufacturers who see them as a marketing tool.

“The beautiful thing about learning is that no one can take it away from you.”
---B.B. King

http://waterhammer.hopout.com.au/

 

[zdas04]

The company specification I was looking at called for PE3408 so I assumed that PE80b (because of the "8") was 3408. But 3408 is actually high density (density between 0.941 and 0.965 gm/cm^3) so I'm confused. If PE100 is medium density then I'm not sure what they ended up running.

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.
The plural of anecdote is not "data"