Low temperature piping and pipeline

[kloroform]

hi all,

i want to evaluate the capability of existing piping (ASTM A 106, Sch 40) and pipeline (API 5L X65 sch 80)
is it capable to be operated in low temperature (33 F) and pressure (530 psia) ?

as far as i know, low temperature will give significant effect in brittleness, but how do i evaluate this ?

i need your help. thanks in advance

 

[racookpe1978]

Now, look up the brittle fracture temperature of your material (steel, ASTM A 106, right?).

What temperature do you read from the table?

 

[SJones]

API 579-1, Part 3

Steve Jones
Corrosion Management Consultant

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

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

 

[BigInch]

Temps are within the working range of A106 and 5L

Where you may get trouble is simply from stress reversed from usual patterns. Instead of compression you will have tension in axial direction. Axial tension combined with tension in the hoop actually produce a lesser total shear stress and axial tension eliminates the potential for Euler buckling. Design for tension and you have it beat.

 

[LittleInch]

Temperature, yes, 33F, (0.5C) is not "cold" enough to affect the properties of most common steels. You probably need to get below -20C before you run into limits.

Pressure - Depends on the size and wall thickness. BTW most pipelines designed to a pipeline code are described in thickness of steel not schedule, but that's probably just me....

The real issue at that temperature is frost heave, constant condensation and ice forming on any above ground bits of pipe or equipment plus as BI says, the pipe will be in tension due to temperature and pressure effects.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[weldstan]

What is the diameter? What is the hoop stress generated by the pressure? Is the X-65 seamless?

As BI and LI have indicated, you should not have any great concerns.

 

[BigInch]

LI 33 is 1F above freezing ... LOL

 

[LittleInch]

You think that it is going to be that accurate..... If the ground freezes naturally, it won't thaw out with that next to it.



Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[georgeverghese]

Beware of legacy carbon steel piping grades that are not killed or semi killed. Not sure if these legacy carbon steel grades were classifid as A106B also. So check the base piping class and the year of manufacture of these grades you are looking at.

If carbon steel is silicon killed, it should be good down to -20degC without further testing.

Vaguely recall grades manufactured pre 1990 (?) are the ones to watch out for.

 

[Shmulik]

The question that has to be answered is: whether or not the piping material base metal (i.e. pipes, fittings, flanges), weld deposits and heat affected zone of welds are qualified for the (new) design temperature.
Assuming your system was designed according to the rules of ASME B31.3 (process piping), please follow the instructions of 323.2.2 for low temp. limits and toughness test requirements.