Is AISI-302 stainless steel good for the reservoir with nutrients?

[Sam&Max]

I am wondering if AISI-302 stainless steel parts are suited for permantent contact with the nutrients? It is because I am thinking about using a non return valve which in the reservoir which has AISI-302 grade parts.
I don't know how aggressive the nutrients are to metals and if this kind of stainless steel might bleed toxic stuff into the reservoir.... Any idea?

 

[Renfro]

It's fine. No worries.

 

[Renfro]

Brass and copper should be avoided due to corrosion issues. Stainless steel is good to go.

 

[Sam&Max]

I am asking there is differences between types of stainless steel and if there is needed stainless steel grade for salt water or if the type below (AISI-302) is already good enough?

 

[Renfro]

Well as far as chromium goes, 302 has a pretty high percentage 18% so thats good for anti corrosion. Nickel is at 8%. Basically it's the same as 304 but with more carbon. Good for making springs. Often used in medical, kitchen, food processing...

It can generally withstand acid solutions up to 3%.

 

[Sam&Max]

I did read that AISI-316 is recommended for salt water applications because it shows good resistance against chlorides. Do you know how strong is the nutrient solution compared to salt water???

Where you read the information that it generally withstands acid solutions up to 3%?

Do you know if corrosion is always seen by the eye? Or maybe the metals can emit into the nutrients and you see nothing (maybe beginning of corrosion)?

 

[Atomizer]

Most nutes are slightly acidic which will have no effect on stainless. I`ve used SS cornelious kegs for years to hold nutes and they are still perfect inside. If its just a non return valve i wouldnt worry about it hurting the nutes or the nutes hurting it.

 

[Renfro]

Do you know how strong is the nutrient solution compared to salt water???

Sea water is about 35000 PPM, so it's over 20x stronger than the average full strength nute mix.