Galling of Stainless Steel Threaded Plugs
Galling of Stainless Steel Threaded Plugs
(OP)
We have a number of 2205 duplex heat exchangers in our facility that have 316 stainless steel threaded plugs incorporated into their design. These exchangers operate at approximately 300°F, is anyone aware of experiences whereby plugs in this type of service leak? Also, Does anyone have any experiences with galling between a 316 stainless steel plug and duplex steel plate? Any suggestions with respect to torquing?
Sincerely,
Alloy2205
Sincerely,
Alloy2205
RE: Galling of Stainless Steel Threaded Plugs
316 SS vs 2205 SS has a threshold galling stress of 2 ksi.
2205 SS vs Nitronic 60 SS has a threshold galling stress of 30 ksi where 50 is consider very low galling tendencies. Depending on the enviroment this may be solution.
I don't have the self-mated numbers but would imagine that it very low.
What is the enviroment that the materials are seeing?
RE: Galling of Stainless Steel Threaded Plugs
2205 is a bit better than 316 at gall resistance, but they are rather bad.
= = = = = = = = = = = = = = = = = = = =
Corrosion never sleeps, but it can be managed.
http://www.trenttube.com/Trent/tech_form.htm
RE: Galling of Stainless Steel Threaded Plugs
the service environment for these exchangers is primarily a combination of light hydrocarbons, hydrogen, H2S and water.
RE: Galling of Stainless Steel Threaded Plugs
RE: Galling of Stainless Steel Threaded Plugs
I think you could use a Nitronic 60 SS plug in your case, I certainly would try one or two. Not gall proof but a lot better than other combinations.
I'm also looking for a good combination where you might use a bushing of a different material that would have less tendency to gall with a pipe plug of still another material.
I have used this approach in the past. The H2S makes this a little tougher.
Although milk of magnesia is good anti-seize under certain conditions I would not use it in your case being that you have a slightly acidic solution containing chlorides. I would be a little afraid of the formation of magnesium chloride in some crevices.
Here is one that I’ve used with very good success in similar environments.
Therm-O-Plate 110
http:
RE: Galling of Stainless Steel Threaded Plugs
I had previously had enough experience with galling of SS nuts and bolts on a variety of equipment from turbine bolting to Hx's to know the problem, and the commercial anti-sieze's available on the market, and to know that the demonstration was bona-fide and the results were real and quite impressive.
Given your problem, that is the first place I would go to find a solution.
They had a MSDS sheet on the stuff, so you can see what is in it, but not how it is formulated.
I will leave it to you to search their site for this product, or contact them for specific info.
rmw
RE: Galling of Stainless Steel Threaded Plugs
http://www.fastorq.com/lubes.htm
It fits within your temperature requirement.
Good luck
rmw