Is there any way for use S235 J2+N for pressure vesel Acc. to EN 13445??

[yigithan]

Hello everyone .
I know that I can use some S series steels for pressure vessel Acc. to AD2000 Merkblatt ( İf T= less then 300C ; p.d<20000 etc.)
I wonder is there any way to use S series (S355 or S235 ) steel for peressure vesels. Maybe With PMA ?

 

[MGZmechanical]

I know there are some certificates from TUV for certain steels. But I think it only covers steel from certain steel mills. Mterials for PED must be included in an harmonized standard for pressure vessels steels. AD Merkblatt materials may not be valid under PED (in fact I would not use S235 for pressure vessel if third party audit needed).

S355J2 is a problem because is a typical material for hollow bars. And it is very dificult (impossible) to find hollow bars in material other than S355..

See a certificate from TUV:

http://www.vitkovicesteel.com/data/..._Geltungsbereich Scope (Annex)-FB-320_eng.pdf

I wish I could be of more help but we always use P2655GH, P355GH. And fortunately due to a change in the design we got rid of the hollow bars so we avoid the problem

Best regards

 

[XL83NL]

Why would you want to use a steel grade designed for structural applications under a pressure bearing application? That's what I dont understand. If it where for the supports, I can see a reason.

Mterials for PED must be included in an harmonized standard for pressure vessels steels.

Thats not correct. There 3 ways to use a material under the PED;
1. By using material which comply with standards that are harmonized under the directive
2. By using material covered by the EAM (European Approval of pressure equipment, materials).
3. By using material that the pressure vessel manufacturer assessed appropriate and has issued a PMA (Particular Material Appraisal) for.

Option 2 is very unlikely to be used, as it has proven to be impractical. Option 3 is what we see most when vessels are designed acc ASME VIII-1.

 

[MGZmechanical]

Well, yes there are those three ways. But as far as I know, as you noted, EAM is quite difficult (I don't know where is the official list now but it used to be quite short and many ASME materials where not listed). I have never tried the PMA method (I used to think that it should be as difficult as the EAM).

Only reason I see to use structural steel for pressure vessels is the hollow bar in S355J2 to manufacture fittings.

In any case the materials point is quite strange for me in the PED. The only requirement is that the material is adequate for the use, with a Charpy value of 27 J and deformation 15% before rupture. Then, why is no possible to use S235, S275, S355,.., which are materials that fullfills those requirements?

Best regards,

 

[XL83NL]

EAM is indeed quite difficult, and the list is short. Over the years, it has proven to not be useful.

PMA however is very easy for most applications, and is done all the time. How else would all those thousands of pressure vessels and piping systems, designed each year to VIII-1 resp. B31.3, be compliant under the PED? Iti s far more easier than EAM. And, once you have a PMA for say use of SA312 TP316/316L under VIII-1, signed off by a NoBo (which required for cat III and IV), you can re-use it all the time within the limits of that PMA. So make sure you make your PMA's smart so you can re-use them.

In the past Ive written a few replies on this subject, see

https://tinyurl.com/ydc8wayb.

Also, as an addition I'd like to make sure these are called out;
- ASME PTB-10
- PE-03-28

Is you will read from my previous replies is that reference of the PED (2014/68/EU) on the 3.1 CMTR is sufficient as well.

However, if you want, I dont see immediate reason why S355J2 couldnt be used for pressure vessels purposes.

 

[KVdA]

Simple, because S355 or S235 is structural steel and not steel for pressure purpose.
So in fact using S355 or S235 is a big no no, and in conflict with the annex 1 §4 PED requirement (even if you would comply with all other ESR's when setting up the PMA).

As stated in the OP, AD2000 allows the use of those materials and even provide allowable stresses at higher temperature for some of those steels. But beware, AD2000 is in some parts clearly in conflict with the PED so if you have a NOBO who does his job, he needs to refuse.

 

[XL83NL]

So in fact using S355 or S235 is a big no no, and in conflict with the annex 1 §4 PED requirement

Can you elaborate where in para 4 this is directly or indirectly implied? Im not saying I dont agree on using structural steel for main pressure bearing parts on pressure equipment, however (purely from a legal perspective) if the PED is not explicit in this matter, there's a basis for argument with a NoBo during a conflict.

 

[KVdA]

"Materials used for the manufacture of pressure equipment shall be suitable for such application during the
scheduled lifetime unless replacement is foreseen."

Although I'm not a lawyer, I think It's rather clear that structural steel is not suitable to be used in a pressure vessel (knowing there is steel specifically for pressure purposes out there EN10028-2...). Also looking at the scope of EN10025-2 its clear that the material is only suitable as structural steel, also note that there is no reference to the PED.
The sole reason of a PMA is to check al ESR's of the PED of "foreign" material but which is (quite obvious) still suitable.

 

[XL83NL]

I guess you're right. In light of that section of the PED I'd rephrase my previous reply - structural steel isnt suitable for main pressure bearing parts in pressure equipment.

 

[Vikko]

As far as I know you can use it with no problem at ambient temperature (TS=20°C) or where it is not containting a pressure (PS=0MPa).

The steel grade S235J2 (1.0117) is defined only in the harmonized standard EN 10025-2: "Hot rolled products of structural steels. Technical delivery conditions for non-alloy structural steels" according to:

http://www.steelnumber.com/en/steel_composition_eu.php?name_id=6

If you check into the standard EN 10025-2, it is defined the minimum yield strength (235MPa (up to 16mm thickness)) and minimum tensile strength at room temperature. But it is not defined anywhere inside there, the guaranteed minimum yield/tensile strength at another specified temperature above of it (as it is for example in EN 10028 or EN 10216/7 standard series where the properties of strength are specified any 50°C up to 500 or 600°C (depending on the grades)). According to EN 13444-3 tab. 6-1 to calculate the admissible strength you need the yield and tensile strength specified at the design temperature (TS) of the component/pressure vessel. When this is not specified into the material standard, you can evaluate it with very low (they are really low which finally makes unpractical to use such material above ambient temperature or for ) coefficient up to 300°C only, according to table 4.2-1 of EN 13445-2.

For the PED law, you have to use harmonized standard: EN 10025-2 is one of them, so you do not need PMA (that is needed only for ASTM materials)).

 

[XL83NL]

For the PED law, you have to use harmonized standard

Incorrect, as mentioned; PMA or EAM are 2 possible alternatives.

I'd add a little more nuance to that phrase really; even not all EN standards are harmonized. Material standards (such as EN 10216-5) referenced in EN harmonized standards (like EN 13445 or EN 13480) can be assumed to be harmonized, but it always has to be checked using the above list.
Furthermore a PMA can also be required for materials conforming to other standards than ASTM. Though ASTM may be the most familiar standard, a lot of other standards are not covered by the list published by the EU.

 

[Eser Temiz]

Dear all,

S - structural steel plate can be used within PED.
EN 14394 harmonised standard allows the structural steel in boilers with some limitations.
S235JRG2, with a desing temperature max. 300C and a design pressure max. 6 bar, having thickness of max. 20mm.

For pressure vessels AD-2000 code allows S steel plates with some limitations, like design temperature max. 300C, dixP<=20000, max. thickness 150mm, and normalized.

But in both cases PMA is required by PED.

If AD-2000 code is selected for design, then manufacturing and inspection also shall be performed acc. to AD-2000 code, and in addition to these PED requirements are performed.

So, S-structural steel can be used within PED? Answer is YES, but with some limitations acc. to the design standard and PED.

 

[Vikko]

even not all EN standards are harmonized.

I didn't know about such a list.

Anyway, for calculation according to EN 13445: the stress strength values at design temperature are needed for the calculation of admissible stress and shall be defined in the material standard. So EN 10025 does not defined anywhere these values and therefore it is not possible to calculate admissible stress at 250°C. (I always assumed that for the same reason not all materials can be used in creep range, because it is not defined the creep strength values anywhere in EN 10216/7 as it is in EN 10095 for example.)

 

[MGZmechanical]

In EN 13445-2 Table 4.2.1 gives some reduction factors up to 300 ºC for steels without guaranteed values at high temperature. This are just for cleaning and drying operations but it is a reference.

Best regards

 

[ulyssess]

For the PED law, you have to use harmonized standard: EN 10025-2 is one of them, so you do not need PMA (that is needed only for ASTM materials)).

EN 10025-2 is not a harmonized standard.
EN 10025-1 is a harmonized material standard, but not according to PED. EN 10025-1 is harmonized according the CPR (European Construction Regulation).
All material standards harmonized under PED are listed under

http://ec.europa.eu/growth/single-market/european-standards/harmonised-standards/pressure-equipment/

If PMA is always possible.

When this is not specified into the material standard, you can evaluate it with very low (they are really low which finally makes unpractical to use such material above ambient temperature or for ) coefficient up to 300°C only, according to table 4.2-1 of EN 13445-2.

Table 4-2.1 applies only for low temperature steels. EN 10025-2 does not contain low temperature steels.