6 replies to this topic

[STT]

Dear All,



My name is Setiawan from Indonesia. I would like to ask some questions as per tittle.



1. Is carbon steel completely forbidden to be used in food contact equipment or machine?

2. If I have a carbon steel wire conveyor and it will be used to convey product through a coating machine. Coating paste is basically emulsion of oil, fat, cheese cream, salt (8%), etc. (moisture content <0.1%). Will the carbon steel corroded, considering that the carbon steel is continuously wetted by oil emulsion?

3. Is there is any guideline for choosing what type of stainless steel should be used?

I tried to google this however I'm not able to find the guideline for this, I only can get the basic guideline, e.g. SS 316 application is for components used with more corrosive foods (e.g. blood, meat, food with moderate salt content), which are frequently cleaned, with no stationary solids, and not under excessive heat. However this guideline is not specific enough : moderate salt content, is 5% is moderate or 50% is moderate or else? Excessive heat, is 50 C excessive or 100 C or 200 C or even more is excessive? . is there is any practicable way, let say, if the product pH is below x, or  temperature more than y, or salt content more than z then I should pick SS 316 instead of 304.



Thank you.

ST

[cazyncymru]

Dear All,



My name is Setiawan from Indonesia. I would like to ask some questions as per tittle.



1. Is carbon steel completely forbidden to be used in food contact equipment or machine?

2. If I have a carbon steel wire conveyor and it will be used to convey product through a coating machine. Coating paste is basically emulsion of oil, fat, cheese cream, salt (8%), etc. (moisture content <0.1%). Will the carbon steel corroded, considering that the carbon steel is continuously wetted by oil emulsion?

3. Is there is any guideline for choosing what type of stainless steel should be used?

I tried to google this however I'm not able to find the guideline for this, I only can get the basic guideline, e.g. SS 316 application is for components used with more corrosive foods (e.g. blood, meat, food with moderate salt content), which are frequently cleaned, with no stationary solids, and not under excessive heat. However this guideline is not specific enough : moderate salt content, is 5% is moderate or 50% is moderate or else? Excessive heat, is 50 C excessive or 100 C or 200 C or even more is excessive? . is there is any practicable way, let say, if the product pH is below x, or  temperature more than y, or salt content more than z then I should pick SS 316 instead of 304.



Thank you.

ST

You need to look at obtain equipment that is made from either 304 or 316 stainless steel
Nothing stopping you using it, but check what your legislation on food safety says, and if you have BRC then it's definate a no no! BRC will expect you to have statements or certificates of conformity for all of your equipment.

C x

http://www.bssa.org.....php?article=45

[STT]

That's why I am asking this forum regarding the usage of carbon steel for wire conveyor. I believe that it still will generate corrosion eventhough during the operation, it continuosly wetted by oil. I believe that small amount of trace water + high salt content + exposure to air (oxigen) enough to start corrosion occur. However I still can't get the "literature" or opinion from experienced people for this so I could tell my boss and convince him.

For point 3, I really apreciate if I could get the "complete and specific" guideline in selecting stainless steel. I know that SS 316 is better in term of corrosion protection compare with SS 304, so I have to choose SS 316 for more corrosive product. But how corrosive? Example, If I have product with pH 5, does it have to use SS 316 or I could use SS 304. Example 2, if I have product with salt content is 8%, temperature 38-40 C, could I use 304, or I should use 316 or better? This "specific" guideline is what I'm looking for.

Thanks.

[AS NUR]

That's why I am asking this forum regarding the usage of carbon steel for wire conveyor. I believe that it still will generate corrosion eventhough during the operation, it continuosly wetted by oil. I believe that small amount of trace water + high salt content + exposure to air (oxigen) enough to start corrosion occur. However I still can't get the "literature" or opinion from experienced people for this so I could tell my boss and convince him.

For point 3, I really apreciate if I could get the "complete and specific" guideline in selecting stainless steel. I know that SS 316 is better in term of corrosion protection compare with SS 304, so I have to choose SS 316 for more corrosive product. But how corrosive? Example, If I have product with pH 5, does it have to use SS 316 or I could use SS 304. Example 2, if I have product with salt content is 8%, temperature 38-40 C, could I use 304, or I should use 316 or better? This "specific" guideline is what I'm looking for.

Thanks.

Dear Setiawan...

To see decide which one that suitable for you 304 or 316?.. you can see how corrosive your water.. that using Langelier Saturation Index count..with LSI you can see the corrosivity properties of your water.. after that you have to look specification of your 304 and 316..
here the attachment to understand LAngelier saturation index


SALAM

AS Nur

Attached Files

•  Langelier_and_aggresive_indices.pdf   52.77KB   163 downloads

[STT]

Dear As Nur,

Thank you for your reply. Yes, Langelier Saturation Index could be used for water based solution. However do you know what could be used for oil based koloid (water content only 0.1%)?

Thanks.

[Charles.C]

Dear Setiawan,

This comment is sort of implied within AS NUR's post but IMEX, the primary source of knowledge is often the equipment manufacturer. Having used steel conveyors etc for various applications ranging from freezing to cooking, I hv usually found that the major suppliers hv (and will share) large reservoirs of knowledge / validatory experience on this subject, after all, it's their reputation involved too. In fact, the absence of such is often a warning sign IMO.

Rgds / Charles.C

[AS NUR]

yes.. agree with Charles.C.. you have to discuss with your manufacturer of machine and piping.. IMO.. the manufacturer have the wide rabge a product, you just discuss and decide which equipment that suitable for you....