European Code- P275NL1 above 100 ¦C.

[Alessandro87]

Dear All,

we have to design a vessel where P275 NL1 have been chosen for the shell/head plates.

Design temperatures are -35°C / +130 °C.

How is possible to obtain the " MINIMUM VALUES FOR THE PROOF STRENGHT RP0,2 AT ELEVATED TEMPERATURES" ?

The reference standard EN 10028 has no info about this important values.

PV elite calculates the derating of the material making reference to this standard but no info are available.

Have you ever faced this matter?

thanks all

 

[denlow60]

this material is a low temperature material.

 

[ulyssess]

Ask the material manufacturer if he can certify steel grade P275NH for the material delivered. If yes, minimum values at elevated temperatures are given in the standard.

 

[Alessandro87]

denlow60 your reply sounds to me obvious and useless.you could have avoided it.

Thanks Ulyssess for your reply.your suggestion is something that can fit for my problem.
Anyway,there are no constraints to use Nl1 material for these temperatures,aren't they?

 

[denlow60]

Alessandro87

Thank you that you still have faith in me .
just look at this pdf, maybe you have something on this file.

 

[Alessandro87]

denlow60!this is a good reply.Thank you!
could you please tell me the standard where you took this Page?
Thank you in advance!

 

[denlow60]

Alessandro87

this pdf come from EN 10216-3:2002

 

[Alessandro87]

thank you !
this is for pressure pipe...on the pressure plate...nothing...but anyway I think the behaviour with T depends on material category..thank you!

 

[XL83NL]

If you require stress values for a certain grade, you need to determine those from the relevant standard acc. which the product form is made, e.g. EN 10216-5 for smls stainless steel pipe.

You cannot use values from another product form standard, unless this explicitly allowed, e.g. when using fittings like those from ASTM A403 which may be made from pipe acc. ASTM A312.

 

[denlow60]

XL83NL

P275 NL1 is found in ISO / TR 20172:2009 ( E ) group 1.1 in three standard , if you want to find an answer for this kind of material you need to look in EN 10216-3 , EN 10217-3 , EN 10028-3.

 

[OSIRIS7]

Because of the 130 degree Celsius you are 10 degrees too high to use an alternative calculation should you be designing according the EN 13445 code.

I would suggest to use a different grade. However, I am at home now, and can not look into the standard right now. Otherwise I could advise.

 

[XL83NL]

Denlow, you cant just use stress values from e.g. en10216-5 if youre using plate acc a different product form standard. Different manufacturing methods result in different material properties (incl stress values) for the same grade, esp. with carbons steels.

As Osiris, I dont have the standaards with me right now, so cant check for the correct answer.

 

[Alessandro87]

dear all,thank you for your interesting replies.

XL83Nl is right.I must use the standard for pressure plate.
so EN 10028-3.
The problem,and the reason why I posted my question is that in this standard there is nothing about how this grade Nl1 works above 100°C.

i don't know where I can take this values

 

[denlow60]

XL83NL

if you want to maintain those values ​​-35 ° C / +130 ° C.
then you will have to use a different material

 

[OSIRIS7]

Why not use EN 10028-3 P275NH and use EN 13445-2 annex B? (assuming that your design code is EN 13445, many other design codes have similar ways)

 

[Alessandro87]

Dear All,

I would like to inform you all that at the end the material used was the P275NL1 and the properties at high temperature taken from EN 13445-2 par 4.2.2.2,table 4.2-1 where factor for derating are listed.

As per par. it's not a good practice to use this low temperature materials at high temperature for long time because this would change the structure of the steel.

In this case the high temperature is not the operative temperature (below 100°C)!

Thank you all for interesting answers!!

 

[OSIRIS7]

it's not a good practice to use this low temperature materials at high temperature for long time because this would change the structure of the steel.

That is correct. But up to 300 ºC you do not really have to worry about grain growth. Above this temperature you should consult a specialist.

Now what is the design temperature that will be stamped into the name plate? I am just curious.