Material for D.I Water

304/304L is used because the deionized water does not seriously corrode the stainless steel. However, the stainless does leach into the deionized water, causing a loss of purity. This is mostly a problem in the semiconductor type processes, not in drinking or food processing. 316/316L is said to be worse for this.

Receommendations are normally to either use a final resin bed after the stainless or else to replace the stainless with teflon.

Things without all remedy Should be without regard: what's done is done. - Macbeth

Guest when you say DI water do you mean DI or do you mean RO reverse osmosis?

I'm not sure that DI is used often used for human consumption; RO is typically what I've seen used.

milo

It will best to use PP or even PVDF. SS316 is a much better choice than SS304, but even so, it will still leach iron ions into the water.

You should use, indubitably, plastic materials. There is a wide choice: PP, HDPE or PVC, etc. every common metal will leach into the DI water.

pvc is a horrible choice for d.i. water...becomes extremely brittle like glass over time...the d.i. water leaches all ions from any surface it comes in contact with...pvdf is my choice

Actually 304 is the better choice for high purity water systems. The iron is held more tightly in the alloy than it is in 316, but since 316 is more common, it is used much moreso than 304. Both will dissolve iron into the system over time (rougeing) and the difference in the rate between the two alloys is not significant.

I do not reccomend SS for most applications, CPVC is generally very good for all temperature levels and has a very low level of leachable contaminets.

If you have more questions about Deionized water please feel free to call me at work. I have been dealing with Ion Exchange resins for over 10 years. my company has been in business for over 20 and we have a combined amount of almost 100 years of technical knowlegde.

I am ResinTech Inc. International Sales manager and my web address is www.resintech.com you can also post DI questions there.

Best of luck in your application,

Seth Rockmacher

Water as grubby as 1.0μS/cm is handled in highly-polished 316 very well. For biological protection, keep it above 60degC, keep pipe branches below 3 pipe diameters in length, use sanitary diaphragm valves and sanitise when necessary.

For ultrapure water at ambient in the 18MΩ.cm region, it's a different game altogether. More stages of processing are needed before coming to PVDF as a final loop piping material.

So, it depends upon what is meant by "DI water", really.