Titanium or Hastelloy 1

[topgun67]

Hi,
I have been asked to replace an existing carbon steel sea water cooling line with a Titanium one. It is 200mm nb. Fitings and elbows in Titanium are impossible to procure. Hastelloy is more readily available. Does anybody have any thoughts on Hastelloy or maybe 316l Stainless as an alternative to Titanium? This is on UK Nuclear power station
Thanks for your time

 

[andyenergy]

Sea water and 316L doesn't sound like a good idea to me. I don't know enough about Hastelloy to comment. You might wish to repost in the corrosion engineering forum - always plenty of good responses there. Is this Magnox AGR or PWR?

 

[topgun67]

Many thanks for your help Andy. It is PWR. We are attending site today and one of the points of discussion will be the unsuitability of 316L. Will post a thread on the materials page about Hastelloy.

 

[arcer]

Have you considered contacting Haynes and asking for they're technical assistance? In the States their # is 800-354-0806.

 

[MJCronin]

topgun....

I may be a little late to this thread, but there are a number of power plants in the USA that have used AL AL6XN or coated/cement lined carbon steel etc befor they went to the expense of titanium.

Have you considered posting your question in the "Saltwater Corrosion Engineering Forum" ???

Or have you already found a solution ?

-MJC

 

[madburyengr]

Consider AL6XN or Inconel 625.

 

[an0r0v]

In general, 300 series SS are very susceptible to chloride stress corrosion cracking while some of the hastelloys (there are various hastelloys with varying compositions and amounts of molly) such as c276 and c4 are not. Hastelloys are very easy to weld and unlike titanium, fittings are also available. You need to be carefull when acquiring them, nowadays lots of them are made in mom-and-pop furnaces all over the world and, their qc has a good bit to be desired. You should have no problems if purchasing them from a reputable maker such as Haynes or Cabot. Make sure you get the mill spec reports.