Corrosion engineering | Forum profile

Every Engineer should have a CMA plan in his repertory.

definitely

Hmmm, good point, why didn't I think of that? So finally, yes, (too much) teflon tape does interfere with the cathodic protection. Gracias.

If you do, indeed, need the seal then you have to be careful how much tape you use. If you use a lot and do not tighten the thread enough you can insulate the joint. You could use an ohm meter to check conductivity.

( try with NACE . www.nace.org , or you can buy the EFC, http://www.efcweb.org/ , european federation of corrosion, publication n13, predicting co2 corrosion in the oil&gas industry, where is contained also the paper of NACE. S , )

( Agreed.  The NORSOK and draft NACE standards are a little weak.  NORSOK because it is focused on offshore Norway and ISO because there are too many factions involved in its production. The issue with NAB in sour water is conversion of the passive oxide layer to copper sulphide which then opens up the cathodic reaction to increase the corrosion rate.  The question is:  in...

Appreciate the additional info and I hadn't thought to look at 571.  I'm going to stay away from the NAB for sour produced water and leave it for sweet produced water (per the old RP0475 guidelines).  

Generally you should not use the tape on the lowest threads, since the lower threads will cut it leaving loose pieces of tape in your cooler. Same with compound, put it higher up on the threads. Unless you skip the wrench and finger tighten only, you will not have an insulated joint. Even at low pressure, I would not skip the thread sealant. Tiny leaks have a way of getting worse.

( The only problem is that to properly paint them they will need to be dismantled and preped \(blasted and washed\).  If you are doing that then replacing them with HDG isn't much more effort. If you paint them you will need need to inspect and repair the coating regularly. , )

Fair enough.  I would go one step further, i.e. put my concerns in writing to the client.  But the problem with this approach is that the property could change hands, in which case a new owner would be stuck with a substandard construction.