Originally Posted by JackNaylorPE
Originally Posted by B NEGATIVE
Nonsense. Every impingement block on the market has SS jet plates,Watercool and Aquacomputer all use SS covers for their GPU blocks.
Ss is perfectly fine for use with copper..my own loop has SS and copper tube together with no iIl effects.
And how are you measuring these effects ? .... have you examined the inside of the tube, have you measured the electrical conductivity of the water ?
I was strictly referring to Type 304 stainless steel from which SS tubing is fabricated. I was not referring to type 316 stainless steel typically used in machinery and extreme environments. Anodized aluminum shows better corrosion resistance than Type 304 SS. I oft inspect submersible pumping stations which consist of a underground concrete chambers with an anodized aluminum access hatch and Type 304 SS electrical panels.... the aluminum hatches are free of any sign of corrosion and the panels have surface rust.
There are many types of stainless steel ... Assuming all SS's are created equal is an unfortunately common error in plant design.
Type 316 is specifically formulated for it's corrosion / galvanic resistance as well as hardness / abrasion resistance to make it suitable for use in rotating machinery as well as extreme environments such as chemical and marine industries. It is very, no extremely, expensive.
Type 304 on the other hand has much weaker corrosion and galvanic resistance and is used where large quantities would make 316's usage cost prohibitive. Boat railings is a common usage for example.....and that's why if not plated or maintained, they immediately show signs of corrosion. It's also softer which makes it easier to bend. SS tubing and piping found in your typical hardware store is Type 304 at best.
Stainless Steel type 316 electrical panels used in NEMA 4X environments remain free of rust after 30 years of use except sometimes for a small spot or 2 at weld points where it will discolor but not corrode. Type 304 stainless steel panels will show signs of rust in a matter of weeks in outdoor environments. This surface rust appears in a as small dots and is easily wiped away with a plastic scrubber and some WD-40.
Here's some suppliers:
Type 304 only http://www.cut2sizemetals.com/stainless-steel/round-tube/stb/?utm_source=bing&utm_medium=cpc&utm_campaign=Stainless_Steel_Round_Tube
Type 304 only http://www.globaltecheng.com/ProductCart/pc/viewCategories.asp?idCategory=28
Giving examples of how type 316 SS is used doesn't change how Type 304 behaves; just because 316 is OK and doesn't cause problems, that doesn't mean all other types of SS are OK. I have too much experience with Type 304 to consider using it in a loop. And while the cost of a few feet of tubing is by no means prohibitive, it is difficult to obtain in small quantities.
While the corrosion rate of 304 is slow it does occur and the tube will certainly outlive the computer...... but your fluid will quickly contain significant levels of ions....as for the surface rust, I have never seen clumps or flakes of rust appear in a line but we do see rust staining on filter media when Type 304 is used in feed lines. And of course the scrubbers and towels we use to remove the surface rust from panels are stained rust orange.
A fitting here or there probably won't have a significant influence due to its small surface area.... but I used up over 40" of tube in my build and that amount of surface area should not be ignored.
You didnt spec what SS,you made a blanket statement and you were wrong.
You are also making assumptions of the grade of SS used in waterblocks. Giving lectures in SS grading doesnt alter any of that,as for listing suppliers...why would i ever need that information? Copper is by far the better tube for this application,good enough for potable water systems then its good enough for me.
I have inspected the top covers of my GPU blocks and CPU jet plates,no corrosion found. As for 'significant ions',that occurs the moment the bottle is opened.
Now,using a low carbon steel is great but you are massively overemphasizing the problems with 304. The tallest manmade monument in the US, the St Louis Arch, is entirely clad in 304 stainless steel plates. Except for cleaning, the stainless exterior of this monument has required no corrosion maintenance.
304 is closer to Copper in the corrosion table,the condition your 304 is in is far different to our use,we do not use high chloride content fluids in a stagnant environment.
During the machining process, a microscopic amount of free iron may be worn off the cutting tool and transferred to the surface of the stainless steel workpiece. Under certain conditions, a thin coating of rust may appear on the part. This is actually corrosion of the steel from the tool and not the parent metal. Sometimes the crevice at the embedded particle of steel from the cutting tool or its corrosion products may cause an attack of the part itself. A simple Citric or Nitric acid bath will passivate the steel before use anyway....nullifying any major problems associated with spot rust as the surface will be cleaned and have a protective carbide film
I have been a plumber for a number of years and work with a lot of SS,304 is used for chemical processing equipment, for food, dairy, and beverage industries and for heat exchangers,plenty of resistance for what we use it for.