Going to go ahead and echo SnTMan here. Review UCS 56-1, specifically note (b).
Software like Compress is a useful tool, but it does not supplant knowledge of the code.
Nathan Brink
Cleanliness is paramount in welding on things that have been in elemental sulfur service. Just a tiny amount of sulfur makes its way into that weld and you'll hot crack as fast as you can lay down a bead.
Have had good luck with blasting followed by washing with muriatic acid and finally...
I'd recommend reviewing ASME PCC-1.
While a lot of folks specify some % of yield across the board (50% being pretty common), that won't necessarily be the right number for all joints.
Nathan Brink
Talk to whoever does your water treatment.
Have seen hydrocarbon leak into condensate return, which ends up in the feedwater. Can make for some nasty deposits.
Nathan Brink
Two things to consider, having dealt with substantial sulfur condenser leaks in the past:
1: What side was the corrosion actually on? Yes, the process can be rather nasty if it gets too cool, but unless inspection ruled it out, consider the possibility of the leak starting on the waterside...
Vessels are often full of process fluids that carry heat away from the vessel walls, whereas the skirts will heat up and fail in very short order.
Nathan Brink
I know I've seen black stainless fasteners before. Google tells me MIL-DTL-13924D calls out an "Alkaline oxidizing process" for abrasion resistant black finishes on 300 series stainless. Might be worth asking around if anyone can do a MIL-DTL-13924D class 4 black oxide coating...
Nathan Brink
Not going to name any names, but a common well known 100% nickel antiseize.
I've just had terrible luck with nickel antiseize in general. I'm all about moly disulphide lubes myself, but that's a little toasty...
Nathan Brink
If you'd believe it, milk of magnesia (unflavored) does a great job of stopping stainless from galling, and can take quite a bit of heat as well, suspect it would work similarly on inco.
I actually have a bucket of 718 bolts in my office that were all lubed with nickel, and exposed to temps...
I would assume such a pot would be cold drawn from annealled sheet. Why would it sensitize?
My bet is on SCC. Plenty of residual stresses, plenty of chloride, plenty of oxygen.
Makes me look at my stainless pressure cooker a little warily to be sure..
Nathan Brink
There are countless applications where dissimilar metals are in electrical contact with no ill effects due to the lack of an electrolyte.
If an electrolyte is not necessary, but simply that two dissimilar metals are in contact, how do you suppose chrome plating protects steel?
Or a steel stud...
Dhurjati Sen,
An electrolyte is required for galvanic corrosion to allow for the ions produced as a result of the corrosion reaction to move. This is why car batteries don't work when they run low on water. Simply having two dissimilar metals in contact with each other is not enough.
Nathan Brink
If there is no electrolyte, no galvanic corrosion will occur. Not to say that electrolytes can't exist in vacuum mind you, but two dissimilar metals with nothing but vacuum between them won't corrode.
Nathan Brink
Once again, M&Y aren't REALLY that applicable to a leak free joint. I've never met the spiral wound that will seal at 4.5 MPa operating stress, in fact more than one gasket manufacturer has suggested bolt pre-loads to me sufficient to maintain 10,000 psi (69 MPa) at operating conditions...
Certain gaskets require very high seating stresses to "flow" into the seating surface.
That said, I think you'll find the m&y factors to be of limited use beyond initial design.
Nathan Brink
Regardless of acceptability to code, you need to consider the service impacts as well.
For instance, if this was in amine or caustic service, not a chance I'd allow it without heat treatment.
Nathan Brink
Your client wants a very large carbon steel vessel filled with compressed air and water at 5000 psi, in what sounds like cyclic service, and expects to NEVER perform an internal visual inspection in 50 years?
They are going to get someone killed.
Nathan Brink
If you have a tank that has a separate sour water phase (crude oil for instance), I can see only worrying about the hardness for the bottom of the tank where the water will drop out. Sounds like that's what the spec is calling out.
Similarly, you'll often see the bottoms of tanks coated up the...
When you say "brine", what do you mean? 12% NaCl in water and nothing else? Or is there dissolved gasses? Will the headspace be exposed to air? Whats the pH? Etc. Etc. Etc.
Mind, there really aren't many answers to the above that would make a 300 series acceptable in a concentrated brine...
