Swagelok compression nut thread coating

[summerofgeorge]

I picked up some Swagelok compression fittings on ebay. I didn't notice in the picture that there was a off-white/yellowish coating on threads of the compression nut. Anyone know what this is and if it's safe for brewing? I asked the seller but he wasn't sure.

 

[whoaru99]

My guess would be a Teflon-based lube to prevent galling of the stainless(?) threads.

Shouldn't ever come in contact with the beer/wort, afaik.

 

[kladue]

The coating on the inside threads of the nut is silver plating to prevent galling during assembly. The plated area never will come in contact with the inside of the tube fitting, tubing, or process liquids. A heads up though, material can be trapped between tubing and fitting between the end of the tubing and ferrules, which usually resists most cleaning efforts and can infect your beer when used on cold side applications. Having been there and done that before, take them apart and then clean and sanitize to prevent gotchas.

 

[Pombe]

It's a Silver based lubricant/coating for both high temperature and to prevent galling during break/remake of the fitting.

 

[summerofgeorge]

Thanks for the responses! They will all be in the boil or preceding it so I'm not worried about infections. The compression side will also be submersed in water/wort so liquid will get to the coating. Either way, it appears food safe.