Sealing stainless and brass

[Todd1561]

My apologies if this has come up before, I’ve been searching for quite some time without success. I’m going to be joining a type 304 stainless steel female NPT with a brass male. I’ve read that for 2 stainless fittings special Teflon tape is needed to prevent galling. But I can’t get a clear answer on if this still a problem for stainless/brass. Can I use regular old white Teflon tape to seal stainless/brass or do I need something else? This is for potable water.

Thanks!

 

[Tuttles Revenge]

I can't imagine that anything other than teflon tape would be needed.

 

[Sponsor]

 

[Reach4]

Can I use regular old white Teflon tape to seal stainless/brass or do I need something else? This is for potable water.

I tend to prefer a more premium PTFE tape. One non-obvious advantage is they are less filmy and easier to handle. This is not to say that there are not good white PTFE tapes, but the cheapest, thinnest, least dense tapes are white too. That is what I think you were referring to as regular.

 

[Chefwong]

The taper of the thread is what seals it - so tape or dope is just LUBE imo. I don't have the answer on galling mitigation but last time I did something similar, I used a galling lube. Have not had the need to remove it, so no real data to advise if it worked

 

[Fitter30]

Stainless teflon tape has nickel in it and 4 mils thick to help with galling. When tighting when getting close to full tight stop wait a 30-60 seconds fitting cools finish tighting.

 

[Tuttles Revenge]

https://www.grainger.com/product/ANTI-SEIZE-TECHNOLOGY-Thread-Sealant-Tape-2TE52

POLY-TEMP® SSG XHD Stainless Steel Grade Tape is effective and simple to use. Made from high-density PTFE tape, combined with nickel powders. Can be used both to seal and prevent seizing in stainless steel and stainless steel alloy pipe threads. Nickel color.

 

[Todd1561]

Thanks everyone for the input. I wound up using the regular old (25 year old!) Teflon tape I’ve had forever. Seemed to work fine, no leaks. There was also no galling, I took one of the fittings out to check. Attached is the final product, automated whole house water cutoff to prevent floods. I’ll have water sensors around the house at common leak points that connect back to an Arduino to control the valve.