Water sifter size to prevent rust particles?

Hi everyone!

I have faced a problem with rust in water supply system: there was production downtime and no water was consumed for several days, when production started we found some rust in water and therefore we were forced to rinse it for several hours.

In order to protect the customer form rust particles accidentally appear in water we are going to install some sifters. The question is what is the mesh size needed to be used (as HACCP approach requires to set it scientifically based)? There is requirement concerning turbidity only in local legislation, but nothing about particles maximum size. Similar situation in WHO web site - there are some requirements concerning chemical and microbiological aspects only.

The question is rather close to foreign body maximum size that can be consumed by a human without harm, but still maybe someone faced the same situation choosing water sifters and can tell how he/she has done.

I'd suggest determining a preventive action rather than a corrective action. In other words determine what's rusting (root cause analysis) and replace what's corroding with a non-corrosive metal rather than simply allowing the possibility of another shut down resulting in more rusting and needing your filter(s) to capture the rust.

Constantine,

I couldn't see in your post is your water private well or sourced from the city?  If you control all piping then yes as Esquef suggested replace pipe before install, how ever if its city sourced you will have to work with them and explain your issue and work together. 

I had an issue with a city using sodium silicate in their water, well as it goes across red dairy brick floors and dries the silicates precipitate out and stain the brick white.  We had to find a additive on our end to treat our city water to bind the silicate.

G

Hi Constantine,

It may depend on what you are doing with the output water.

I assume sifter = sieve = filter

My guess is there will be a Russian regulation.

if otherwise, maybe -

European_Stds_Guide_LT_EN_LDW10050309.pdf   642.83KB   11 downloads

(eg Pg 15)

Health wise, hazardous foreign bodies in food criteria often depend on shape /  texture / size,  eg hard/sharp, size limits range from zero to Xmm where X  may depend on location, eg Canada = 2mm max. Seems often no specific regulatory size limits for "hazardous".

Thank you all.

Esquef, Gfdoucette07, In fact, we have our own well to get water. Unfortunately there is some part of the pipe system made of iron. As you may know, reinforced iron is usually used for constructions exploited in harsh conditions (big valves, etc.). Of course, it would be much better to replace all the elements with ones made of reinforced stainless steel, but that is quite expensive.

Gfdoucette07, why actually the city needed that sodium silicate to add to water? It seems I have some similar issue.

Charles.C., well, I use water as an ingredient for snacks production.