ASTM A352-LCC mod.

[Pling]

Hello

I have a Russian spec which calls for valve body material as ASTM A352-LCC mod. Does anybody know what the qualifier "mod." implies? Is this material suitable for environmental temperatures of -60°C (-72°F)? I ask because the spec I see: ASTM A352 LCC (in the 2001 issue of Section II of the BPV code), specifies minimum testing temperature as -46°C or -50°F. At first sight I would have said it is not suitable, but I am not a materials engineer.

Thanks for your help in advance

 

[rneill]

This material would normally be permitted to -45 C or -50 F without further impact testing but would be permitted to lower temperatures with impact testing at those temperatures. Perhaps the "mod" signifies that a lower test temperature is required ?

 

[Pling]

Thanks rneill. It might be that.

 

[metengr]

Don't assume anything when it comes to foreign specifications that are translated to English specifications and/or equivalents.

For example, there are supplementary requirements in ASTM A 352 such as the one below.....

S22. Impact Test Temperatures
S22.1 When an impact test temperature other than that listed
in Table 1 is used, the lowest test temperature at which the
material met the impact test requirements shall be stamped
with low-stress stamps on a raised pad located immediately
ahead of the material symbol; for example, 25 LCB for +25°F
(–4°C) and 025 LCB for –25°F (–32°C).
S22.2 Lateral expansion of V-notch specimens shall be
measured in accordance with 23.2.3.1 of Test Methods and
Definitions A 370, and reported for information.

Perhaps this could be what "mod" is being used for so don't assume anything. Go back to the source and determine what mod is being used for or translation.

 

[stanweld]

Mod could also mean some additional micro-alloying elements like Nb, V, Zr, Ti, Mo.

 

[TomEun]

Normally MODification is not covering the material code and out of supplementary requirements. It means it is not a code material unless the code case permitted.
So you may have to confirm all requirements deviated from ASTM A352, such as chemical composition, toughness, heat treatment, mechanical properties, etc. for the integrity and safety of the service.

Thomas Eun

 

[metengr]

TomEun;
Not sure that I agree with your interpretation of MOD below because there is not enough information provided by the OP;

It means it is not a code material unless the code case permitted.

.

What Code? ASME?? What code case? This material specification was cited in a Russian specification. One needs to go back to the source (Russian specification) to identify what MOD means or what was modified. I don't seem how this pertains to not being a code material or a code case.

 

[Pling]

I do not have the actual detailed Russian specification of the material ASTM A 352 LCC mod. I do have a reference number of a document which supposedly specifies the material and, I expect, the modification as well. (I did not have this reference number when I posted originally.) So, there appears to be a detailed spec. somewhere.

I have also noticed that the Russians call for a lower Ceq for the material than ASTM A 352 LCC specifies. They call for Ceq <= 0,43 whereas ASTM A 352 LCC specifies Ceq as 0,55 max. Also the term 15xBoron is added to the ASTM formula for calculating Ceq.

It appears therefore that the mod. entails more than just the impact testing.

I agree that to get definite information, one has to consult the original Russian spec and all its relevant references.