[Seymour Sunshine]

What is the maximum flow rate through a small (say 11 litre) DI bottle for purifying small quantities of 250 ppm tap water?

[alanwilson]

Normally the max recommended flow rate is the same as the overall volume. So in your case it would be approx 11lpm

[Seymour Sunshine]

My reason for asking is because I have a small number of customers who have really difficult windows to reach trad even with a pole and (as I already have wfp kit) I was wondering if I could get away with purifying tap water directly from the tap to use on these few windows. It may be only 5 or 10 per week, so I don't want to be investing in RO for such a small amount of water use and I don't want to be carrying cans of pure water around with me.

The flow rate I'd need would only be about 5 lpm at the very maximum.

So my question boils down to "Can you use DI to purify tap water directly from a tap for use with a wfp?"

[alanwilson]

Yes you can use Di to purify direct from the tap. The resin will not last very long but as you are only needing it to do a small number of windows then that won't be an issue.

[Seymour Sunshine]

Yes you can use Di to purify direct from the tap. The resin will not last very long but as you are only needing it to do a small number of windows then that won't be an issue.

Thanks for that. It's precisely the information I was looking for. What size vessel would you recommend given that I probably won't be using more than 50  litres of DI water per week. I've measured my working flow rate and it's a tad under 2 lpm.

[alanwilson]

An 11ltr vessel only really holds about 8ltrs of resin which will get you about 700ltrs or so of water.

Personally i think that's probably big enough for lifting in and out of the van/car