A333 vs API 5L pipeline for ammonia transport

wazmoot · Dec 2, 2009

I am trying to determine the best pipeline material spec to transport ammonia (600 psi pump discharge, 200 psi delivery, 66 °F) in 30 miles of 8" steel pipeline.

In essence, is A333 pipe safer than API 5L pipe for ammonia transport? Is either better for the Joule-Thomson effect should there be a leak? Is one appreciably less expensive than the other?

ione · Dec 2, 2009

ASTM A-333 is suitable and economic.
Austenitic stainless steel A-312 could be a more onerous option.

BigInch · Dec 2, 2009

If the best material is the cheapest material that works like you want it to, then see this,

The onshore pipe specifications for the designed ANSI 600 line required 8.625-inch O.D. carbon steel pipe with .277 wall thickness, API 5L-X42

http://www.oildompublishing.com/PGJ/pgjarchive/archie92.htm

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

ione · Dec 2, 2009

wazmoot,
I've missed the temperature. A-333 is undoubtedly the most suitable for low temperatures application. At 66 °F I would use ASTM A 106 or API 5L (by far cheaper than A-333).

wazmoot · Dec 2, 2009

Thanks for the input. Another question: Does the "low temperature applications" of A333 pipe make it less susceptible to cracking/fracturing due to the J-T effect caused by a leak?

BigInch · Dec 2, 2009

What's your JT temperature?

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

SJones · Dec 2, 2009

Also, what is expected to cause the leak, what size is it and would it be normal to ascribe a pipeline minimum design temperature based on the J-T effect at a leak?

Steve Jones
Materials & Corrosion Engineer

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

BigInch · Dec 2, 2009

Very very good question.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

rneill · Dec 2, 2009

I would ask the question as to what is the temperature profile of the pipeline when we shutdown and depressure during routine operations. I would then look at the particular design code and see what guidance it had with regards to a selection of minimum design temperatures.

In the absence of specific guidance in the design code, I would have the latitude to use sound engineering principles and I might determine some pressure (perhaps 30% of design or lower) as being a "pressurized" condition and then I would look at my temperature profile to see what temperature I might hit if I depressured from normal operating conditions to that reduced pressure. It might then be reasonable to select that as my design minimum temperature for selection of materials.

Note: CSA Z662 which covers pipelines in Canada does provide guidance with regards to the selection of notch toughness properties required for different pipelines and so if that were your design code, at a minimum you would have to follow it's requirements.

ione · Dec 3, 2009

SJones,

I think the Joule-Thompson cooling effect due to the depressurization has to be taken into account to determine the lowest achievable temperature. It is not obviously the only or necessarily main factor but it must be ascribed in the list of upset conditions, and so should have be taken into account together with factors related to normal working operations.

wazmoot,

ASTM-A106 is tailored for high temperature service and so the impact test should not even been foreseen (for non-mandatory requirement). ASTM-A333 is specifically described as a material suitable for low temperature applications and so further tests are not required.

SJones · Dec 3, 2009

A leak is a pretty serious 'upset'!! With ammonia spraying all over the place, J-T cooling is going to be the least of your worries, surely? Designing for a leak instead of against a leak seems a bit of the wrong way round to me.

Steve Jones
Materials & Corrosion Engineer

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

ione · Dec 4, 2009

It is clear as an unmuddied lake that it is necessary to design against leak…… anyway leak happens

BigInch · Dec 4, 2009

I think the point is that there are more cost effective solutions to design for (or against) leaks, such as increasing the notch toughness requirements of a 5L, rather than buying A333 where it wouldn't be needed for temperatures encountered during "normal" operations.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

ione · Dec 4, 2009

BigInch,
It’s undoubtedly a valid approach, and (IMO) it doesn’t imply to underestimate possible effects of low temperatures related to leaks, as an increased notch toughness would also lead to a an improved metal behaviour at lower temperatures.

SJones · Dec 4, 2009

Should we then toss a full bore rupture and the resultant J-T cooling into the scenario for setting minimum design temperature or is that just a bit too late (or too big)? I think the point is: what leak will you design for?

Steve Jones
Materials & Corrosion Engineer

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

ione · Dec 4, 2009

The LBB (Leak Before Break) criteria are based on the fact that partial failures are detected by loss of pressure in the plant before catastrophic ruptures occur. Depressurization could imply cooling (J-T effect).

BigInch · Dec 4, 2009

Depressurization (as opposed to explosion) would presumedly be a controlled event, hence the minimum temperature would also be controlled to appropriate levels.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

dcasto · Dec 4, 2009

I've blown down an ethylene line made with 5l x52, thats -121 F, and nothing happens to the line A metalurgist relayed that if anything, the cold working improves the pipe.

unclesyd · Dec 4, 2009

Venting NH3 to atmosphere gives a temperature of -40 the same as used in a auto refrigeration storage system.

Anhydrous NH3 has to have a small percentage of water in it to avoid stress cracking.

BigInch · Dec 4, 2009

DNV approach is to guarantee the ductile behavior of the pipe at a crack tip by specifying a minimum toughness at the minimum design temperature. The minimum design temperature is equal to the temperature above which the steel remains ductile, as defined by meeting appropriate toughness requirements of the drop weight tear test. Where this requirement cannot be achieved, one[/] alternative is to install crack arrestors.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)
http://virtualpipeline.spaces.live.com/

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

A333 vs API 5L pipeline for ammonia transport

Civil/Environmental

Recommended for you

Mechanical

Petroleum

Mechanical

Civil/Environmental

Petroleum

Petroleum

Petroleum

Mechanical

Mechanical

Petroleum

Mechanical

Petroleum

Mechanical

Petroleum

Mechanical

Petroleum

Chemical

Materials

Petroleum

Similar threads

Log in

Part and Inventory Search

Sponsor