To all,
Thanks for all answers!
When we talk about corrosion testing do we mean a ferric chloride corrosion test like ASTM A923 method C? Does this also mean that method C of ASTM A923 is more usefull than method B for detecting intermetallics?
I am curious about the fraction that is still...
Hello all,
Duplex and super duplex grades are prone for the forming of intermetallic phases that lower corrosion resistance and mechanical properties like impact strength.
These phases grow in a temperature range between 950-600 degC during heat treatment and/or welding. After metal fabrication...
Hello all,
Currently we are designing a few hp heat exchangers including NACE MR 0175 requirements.
Materials of construction will be S31803/S32205 DSS, material thickness up to 100mm.
Most of the requirements that are included are understood and can be achieved but the maximal hardness...
A Norsok M650 qualification test record holds a scope (qualification of process) and the tested and qualified thickness and weight.
In some cases a range of qualifcation is also given but in most cases this range is missing.
Can anybody inform me about the criteria that is applicable to...
@XL83NL: Thank you for informing me about the API TR938-C, this is exactly the information were I was looking for.
@Edstainless: Tubes are filled with Argon during the heat treatment after bending and the outside of the tubes are pickled and passivated followed by a neutralizing and rinsing...
Thank you all for given information.
@Metengr: If you perform a locally re-solution annealing of the bend area how can you secure that the transfer zone is free of intermetallic phases due to uncontrolled/slower cooling? I assume that this zone is also very sensitive for SCC during service? Is...
Hello all,
My question relates to the different methods used for bending and heat treating duplex stainless steel (heat exchanger) u-tubes.
To avoid metallurgical problems with the duplex grade material it is prefered to bend the tubes cold. In some cases specifications prescribe solution...
Marty007,
Thank you for your effort. We discussed this CC with our client and AAI, both agreed to proceed with this alternative grade.
Just for interest: Why does it take so long to incorporate this CC from 1999?
Euroweld
Hello Marty,
I kindly thank you for your help, this will help us to proceed with this alternative.
I checked this CC2245 and it includes the use of this material up to 600 F.
In our case this is enough.
Thanks allot,
Euroweld
Hello all,
Recently we booked an order for fabricating a super duplex heat exchanger.
Design code ASME VIII div 1 including U-stamp.
During the procurement stage we are facing some difficulties buying the correct S32750-F53 seamless tubes.
The only option we have at this moment is an...
Metengr
I am not trying to. Just for my interest.
Wanting to get a good view on when to perform or when not!
Also I want to sort out the invluence of the heat treatment towards stress corrosion cracking.
For this view I need a complete situation. I hope this is not against any rule?
Metalguy...
Hello Kingnero,
Kindly thank you for your reply. I am aware of the carbon equivalent (Cev) and its relation to the maximum hardness of the material.
Next to lowering the resedual tensile stress we can make a list of the following factors/reasons to apply PWHT:
1. Diffusion of hydrogen from the...
Good day,
I have some questions that relates to whether or not to apply post weld heat treatment on carbon steel headers.
This question relates to the fabrication of pressure equipment.
Can somebody give me the main reasons for applying pwht by for example an carbon steel header of an air...
@rjvanhofwegen
Switzerland is a so called associate country , take a look at the following websites:
http://ec.europa.eu/enterprise/sectors/pressure-and-gas/pressure-equipment/memberstates_en.htm
http://www.seco.admin.ch/themen/00385/00440/04191/index.html?lang=de
The following text can be...
Dear All,
As pressure equipment fabricator we designed a new type of header for air cooled coolers that contains almost no welds.
Instead of welding plates together we have a design that consists our of a forged block.
The only welding there is for the nozzles and in some cases an endplate. In...
Hello All,
Recently we subcontracted the manufacturing (forging, machining) and overlay welding of some tubesheets under ASME VIII div 1 including ASME U stamp.
This supplier holds a ASME U stamp certification but subcontracted the overlay welding to a welding company also with U stamp...
Metengr,
Thanks, that is helpful. Information is practical, I will read it carefully.
Do you have some personal expierence with this topic?
Thanks Euroweld
Dear All,
Recently we received an order of an Air Cooled Cooler that is fabricated completely of Titanium.
This bundle is a replacement of an exact copy which was built several years ago by another fabricator.
The tubesheet is 25mm thick and the tubes haves a wallthickness of appr. 2,11mm, Dia...
Ulyssess, is it not a little bit strange that purchaser can perform the inspection to obtain a 3.2 certificate? This manner is not that independent! Is this commonly used? I will investigate deeper to find out how and why these companies haves PED certifications by non Nando NoBo"s!
Thanks...
