xylan vs cadmium

[eaw1]

Folks

Which is the betetr coating for bolts/studs etc. in the offshore marine environment ?

 

[unclesyd]

The last time I checked on CS studs Xylan was far ahead of Cd in orders. Blue Teflon was still number one.

 

[unclesyd]

Just had conversation about Xylan studs.
The latest is that Cd is almost a no show and at the present it's about 50/50 between Xylan 1424 (Whitford) and Teflon coated.

 

[TVP]

I agree with unclesyd-- cadmium plating is not really used for offshore/marine environments anymore. Carbon/alloy steels are coated with some type of PTFE-containing coating (usually called resin-bonded PTFE or something similar) such as those indicated above or nonferrous alloys are used, such as stainless steels, titanium alloys, or nickel-based alloys.

 

[SJones]

On health and safety grounds, cadmium should be discounted. See if you can get hold of NACE Publication 02107 where coatings for threaded fasteners are reviewed. DNV State Of The Art Report 2002-3301 is also worth a look.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[TVP]

Here is a link to a DNV presentation based on the 2002-3301 report:

http://www.sintef.no/units/matek/Stalmat/Medlemsinfo/Presentasjoner/Bolter og boltforbindelser.pdf

There was also a 2006 presentation by Bjarte Lillebø of DNV called "Bolting materials subsea" that used to be available for .pdf download but I could not find it today. Perhaps a more thorough websearch would find it.