Coolex Radiators Nottingham

[MattPhin]

I am not a chemist but regularly specify water treatment systems for research laboratories probably similar to Martin's. 

DI water is corrosive.  DI quality is quoted by its resistivity level.  18 Meg Ohm generally being the highest grade and most corrosive.  All DI water wants desperately to attract and dissolve ions which it will take from the surface of any container that it is in or air if an open vessel.  The majority of DI water systems use polypropylene or ABS plastics to avoid this issue. Even high grade stainless steel will be attacked by the universal solvent that is water. 

Distilled water on the other hand is boiled and then condensed to "clean" water taking out mainly particulates and is far less corrosive. I personally wouldn't risk DI water.

Matthew

[maurici]

9 minutes ago, MattPhin said:

I am not a chemist but regularly specify water treatment systems for research laboratories probably similar to Martin's. 

DI water is corrosive.  DI quality is quoted by its resistivity level.  18 Meg Ohm generally being the highest grade and most corrosive.  All DI water wants desperately to attract and dissolve ions which it will take from the surface of any container that it is in or air if an open vessel.  The majority of DI water systems use polypropylene or ABS plastics to avoid this issue. Even high grade stainless steel will be attacked by the universal solvent that is water. 

Distilled water on the other hand is boiled and then condensed to "clean" water taking out mainly particulates and is far less corrosive. I personally wouldn't risk DI water.

Matthew

Thanks for the clarification.

I wouldnt call "risk" altrough... as is what is being used in OEM mixures out of the manufacturing line... so the DI water itself wont attac the system... is true that wont stay deionized for long... as soon as it hits the metal will get charged. But that happens once... and very little, is not continuously hitting the metals like if it was a new supply like in a DI machine?

Again, just half gessing

[Kevin Wood]

Yep, but by the same token, a closed system of water that contains some hardness can only deposit a small amount of contamination before it reaches an equilibrium and does no more harm. For those of us plagued by leaks, it may also help seal some minor weeps too.

I always fill my system with water from my garage dehumidifier, as the tap water here comes from bore holes into chalk, but, as long as a system is not constantly being replenished, I don't think either water will do much harm.

It's when you're constantly topping-up due to leaks that issues might start.

[maurici]

2 hours ago, Kevin Wood said:

Yep, but by the same token, a closed system of water that contains some hardness can only deposit a small amount of contamination before it reaches an equilibrium and does no more harm. For those of us plagued by leaks, it may also help seal some minor weeps too.

I always fill my system with water from my garage dehumidifier, as the tap water here comes from bore holes into chalk, but, as long as a system is not constantly being replenished, I don't think either water will do much harm.

It's when you're constantly topping-up due to leaks that issues might start.

That makes plenty of sense.

Thanks for placing some foundations here!