Stainless Steel Hex Plugs

Is this homework? It doesn't sound exactly like homework but the question is rather basic. I'll assume that you are in Marketing/Accounting/Management and are not an engineer.

So, GIVE THE CLIENT WHAT HE WANTS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

_{Stifles urge to say something really rude.}

Why offer an abusive comment or answer?

The author has every right to have a concern - the dissimilar metals will create and accelerate corrosion and eventually will leak.

I agree Give the client what they want. It is well and fine to express an initial concern to show the customer that you care about trying to provide them with the best service but its their dollar.

No the stainless steel plug should have no detrimental effect on the carbon steel flange. If anything I might try to step up to a 316 instead of the typical off the shelf 304 fittings as the carbon from your flange is less likely to affect it. (stainless steel may discolor from the direct continous exposure to the carbon steel.)

Then you can return to your customer and show the you have there best interest at heart and bill them for it.

In the end its all about the dollar.

There should be no bimetallic corrosion cell forming between SS and CS.

bioramani

Just insure you use a good thread sealant, as the SS can easily gall, I like teflon tape. I have used SS plugs in carbon for years without any problems.

Regarding the "Give the client what they want" comments ... (and post 3) ...

Stainless steels are well documented to be cathodic with respect to carbon steels, and thus, contact between the two will establish a corrosion cell in the presence of an electrolyte.

So the answer to your ("all-too-basic") question is: "It depends on the environment they are in"...

I took a class once, wherein it was explained that IF you want a customer to return, then sell them what they NEED, not what they think-they-want.

Offering the client a smidge of edumacation expresses that you know what you are talking about, and that you DO have his best interests in mind ... then allow him/her to re-think their preferences.

----"PS"----

This basic corrosion question hails back to a lesson taught in NACE classes, about the Liberty ships ... which, in our haste to get them out into battle, sank at dockside whilest being top-fitted ... due to forgetfullness somewhere along the line. Either someone forgot to SPECIFY, or someone forgot to PERFORM, blast removal of all mill scale from the hull plating before installation.

The CS, being anodic with respect to the mill scale, suffered pitting perforation (to 'naturally protect' the mill scale!). This is the kind of "simple error" that continues to occur sporadically to this day...!

Best of luck in all endeavors ~ !

Thanks everyone for your valuable feedbacks!!

I think you have an orifice flange and the tapped hole would be to hook up one side of a DP transmitter in order toe measure flow. They usually come and work in pairs for this purpose and you would need an orifice plate in between them order to measure flow. Most people have went to using flow meters these days but we still have several of these in use in the mill I work at. It is perfectly ok to use a s/s plug although it really isn't necessary. Typically you would screw a S/S instrument tubbing fitting in the hole if you were using the flange for flow measurement and using a S/S plug would be easier to remove later. I have done this many times. The main thing here IMO is that as long as it does not violate any codes and the client wants it then that is a very good reason to install it. One suggestion is to coat the plug threads with nickle based Never seize lubricant before you install it. This will make a good seal as well as make it easier to remove if you ever have to.