ASTM A 453 660 Gr. A & B NACE COMPLIANCE 3

[gengi]

Dear All,

I am performing a design using ASME VIII Div.1 Code and
I am keen to understand if the bolting material ASTM A 453 660 Gr. A & B comply with the NACE 0103 and 0175 requirements ( above all regarding the hardness limit).

I have to design internal bolting in contact with H2S enviroment. I should also try to avoid high strength material BUT the pressure is PRETTY HIGH and the conventional stainless steel material such as B8M, B8MA, B8T do not help me since the relating allowable stress are low with the consequent BIG DIAMETER BOLTS RESULTS.....
(in addition some od them are limited insize).

That is why I would like to use A 453 660 boltings which allow to obtain smaller diameter.

I unsuccesfully tried to find allowable stresses higher than A 453 material but it seems no way than the use of A 453.

many thanks in advance for your kind attention and help.

GENGI

 

[gr2vessels]

gengi,
The hardness of the A 453 660 bolting is not that high as you might think. In fact, is listed around 248 HB, which is much lower than the max. 35 HRC required by the NACE 0175 (I believe that Table A-35 is relevant). I believe that is safe to use it within the limits of NACE 0175 and 0103, as long as it was certified by the bolting supplier as "compliant with NACE MR0175".
Cheers,
gr2vessels

 

[SJones]

How will the supplier provide such certification if they are to have full and complete knowledge of the exposure environment? NACE MR0175/ISO 15156 is no longer solely about hardness values, nickel contents, and heat treatment parameters!

Steve Jones
Materials & Corrosion Engineer

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

 

[unclesyd]

One way to get around big bolts is to use more small bolts if the is designed component.
I recently talked with a bolt distributor about this same problem. He stated that 80%-90% of his orders are for Grade B with a majority being green Teflon coated. Most of the orders are destined for oil production facilities.