Eddy Current Testing---2205

[Metalguy]

To continue this topic in the correct forum, I need help in convincing my NDE guy that meaningful ET can be performed on 2205. I want to use this tubing for retubing 6 2500 tube heat exchangers, and he is the biggest obstacle. Problem is he is a real ET heavyweight, at least on Alloy 600 steam gen. tubing-is a consultant in demand all over the US for nuke plants.

Can anyone lead me to a good source/proof of getting good results with ET on 2205?

"When the eagles are silent, the parrots begin to jabber."
Winston Churchill

 

[EdStainless]

Well you can start by talking with the EPRI NDT center.
The refineries have ETed millions of feet of this stuff. Some like to use full saturation, some partial. Depends on tube size/wall and defect that you are looking for. You can use either permanent magnets or electromagnets, again it depends on size constraints.
I have seen people trying flux leakage also.

The big equipment guys (there are only a few) should all have canned solutions to demo for you.

= = = = = = = = = = = = = = = = = = = =
Rust never sleeps
Neither should your protection

http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[Metalguy]

Here's what I'm up against. Can the refineries all be wrong or do they use larger tubes? I'm losing this battle!

e-mail from my NDE guru.

"Hate to have EPRI agree with me; however, I have talked with both of the EPRI BOP Heat Exchanger program managers and they agree that SEA-CURE is very difficult to inspect.

They are trying with remote field ET and special designed (which means $$$$) probes to find 50% or deeper volumetric flaws. They said that there is not currently available or even in the design stage this probe for 3/4" tubes. And, will probably never be for .049" wall tubes.

EPRI has no experience with 2205. But, if it is duplex it is ET Trouble.

You might say WHY is EPRI doing a bunch of development for SEA-CURE?? Because (name of utility deleted) retubed an entire condenser and had leaks within 18 months. They couldn't inspect to see why or where or ???

Recommendation is still put in something we can inspect."


"When the eagles are silent, the parrots begin to jabber."
Winston Churchill

 

[metengr]

You might say WHY is EPRI doing a bunch of development for SEA-CURE?? Because (name of utility deleted) retubed an entire condenser and had leaks within 18 months. They couldn't inspect to see why or where or ???

Probably it was MIC (only speculation). MIC damage is extremely difficult to find in ss condenser tubes using ECT, and I am convinced that the only material that can truly be resistant to MIC is Ti. We are setting up some trials with Sea Cure (I hope to be proven wrong).

 

[unclesyd]

metengr,

Don't count on SEA Cure vs MIC winning. We lost a test tube in a vertical condenser where MIC was rampant.
The exposure was about 6 months. The colonies were in the middle section of a 30' tube.
The CTW on this system has the tripartite of the bugs.

 

[Metalguy]

Thanks for all the help. Yes, MIC is suspected to be the cause of our severe pitting in the present Admiralty tubing.

The kicker is that there is so much pitting that more ET testing is useless, BUT we have very few leakers--this over ~20 years. The water source is some huge open spray ponds, so anything can and does blow in.

Looks like Ti is going to be our choice--time to bite the $$$$$$$ bullet!

"When the eagles are silent, the parrots begin to jabber."
Winston Churchill

 

[EdStainless]

I have never seen a Sea-Cure tube with attack from MIC. Every failure that I have seen has been:
1. High energy steam dump mechanical damage
2. Under deposit crevice corrosion at alternate wet-dry locations
3. Hydrogen embrittlement from poor impressed current system.
No, I won't name names and plants in the forum.

And #1 and #3 would have killed Ti faster.

There really is an out for you. Tell them that your ET people are requiring the use of AL-6XN or Ti, and then tell them what the cost and schedule impact is.

Can you ET to the resolution, No. But there are other test methods. ID laser scan and UT are a couple that come to mind.

= = = = = = = = = = = = = = = = = = = =
Rust never sleeps
Neither should your protection

http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[Metalguy]

We don't have conditions 1,2 or 3, but even tho we use sodium hypochlorite we know we aren't killing all the bacteria. I'd love to use ozone to zap any SRBs hiding under anything they can find, but we can't (rubber in system for one thing).

Many years ago we failed to chlorinate after hydro (real stupid) units 1 and 2 and had a large infestation of iron-oxidizers (gallionella) that drilled many holes thru our 316L SS piping inside the ponds. Now we have a small amount-? of SRBs, and I know what sulfides do to Admiralty. Strange thing is that of 3 units, unit 3 was always chlorinated and never had the gallionella. However, all 6 HXs (3 units) are full of deep ID pitting, but for the past few years it does not appear to be growing deeper.

The latest news is that we may install a few new Admiralty tubes as a test. I advised them to have some of the test tubes pretreated with ferrous sulfate or whatever is used these days.

"When the eagles are silent, the parrots begin to jabber."
Winston Churchill

 

[HEC]

Hi,
It is a while since I ahve seen any discussion on MIC attack. I know it is off topic, but I recall attending a ISPE conference in Australia (mid '90's) where a Japanese steel mill presented an antimicrobial stainless steel. it was basiclly same metalurgy as 316l with high (circa 5%) copper content. Their testing showed control of all sorts of nasty bugs on teh surface. The application they were pushing was for handrails and that style of fitting. Copper is also used for antifouling on boats. It may be worth further developemnt to look at higher grades incorporating Cu as an adjunct to prevention of microbial growth.
Cheers

Mark Hutton