Stainless fitting vs. Acid PreSoak

[Rudy]

What's with this? Several years ago, I got tired of replacing brass fittings that get eaten up over time. I got some Stainless barb fittings, thinking that they would be impervious to corrosion.

Not so. I'm starting to get leaks now....mostly from the Acid PreSoak Soaps in my automatics.

Is Stainless any better than brass (316SS)?

 

[mrfixit]

It is better, but with Chinese stainless it can be a crap shoot of low quality.

I would replace it with a heavy plastic Barb if your acid is that bad. What brand of presoak... Does it contain HF ?!?


I can post this, a cheap copy from wiki but it is accurate.

.Stainless steel is generally highly resistant to attack from acids, but this quality depends on the kind and concentration of the acid, the surrounding temperature, and the type of steel. Type 904 is resistant to sulfuric acid at room temperature, even in high concentrations; type 316 and 317 are resistant below 10%, and 304 should not be used in the presence of sulfuric acid at any concentration. All types of stainless steel resist attack from phosphoric acid, 316 and 317 more so than 304; Types 304L and 430 have been successfully used with nitric acid. Hydrochloric acid will damage any kind of stainless steel, and should be avoided.[15]

Bases Edit
The 300 series of stainless steel grades is unaffected by any of the weak bases such as ammonium hydroxide, even in high concentrations and at high temperatures. The same grades of stainless exposed to stronger bases such as sodium hydroxide at high concentrations and high temperatures will likely experience some etching and cracking, especially with solutions containing chlorides such as sodium hypochlorite.[15]

https://en.m.wikipedia.org/wiki/Stainless_steel

 

[Rudy]

Yes, it does have a low amount of HF. The fitting is most likely Chinese. Are they cheating on the SS316 specs???

 

[mrfixit]

They do, not all..but many. Americans buy the cheapest they can get usually so they deliver. Lol.

With HF you will go through fittings. Sound like the ss lasted a little longer

Actually the nylon i have is only water lines, I see they make kynar barbs, the kynar is strongest and most acid resistant. Good to 260psi. You should be well below that behind an injector.

Heres an example, just found this online don't know about ordering but they exist. http://www.usplastic.com/mobile/item.aspx?itemid=23769&categoryid=551
.

 

[mac]

I have seen a noticeable degradation in quality for almost everything used in our industry. The Chinese are selling crap. They steal our intellectual property and then sell cheap versions of it. I had a local machine shop that's been in business for 50 years have to reweld a basic component four times . When I asked what was going on they said it was the cheap steel from China.