CR4® - The Engineer's Place for News and Discussion®


Previous in Forum: Precise Duty Cycle of PWM   Next in Forum: Top Eco Fluid Activation Device
Close
Close
Close
21 comments
Guru
Engineering Fields - Mechanical Engineering - New Member

Join Date: May 2008
Location: CHENNAI, TAMIL NADU, INDIA.
Posts: 1794
Good Answers: 62

Material for Pipe Milk Dairy - Milk Transferring to Silo/Packing Machine

11/04/2017 9:04 AM

In a milk dairy for pasteurisation milk is heated to 70 to 80 Deg.C and cooled to 2 to 3 Deg.C, and stored or packed and despatched. The material used for milk flow is SS 304 quality in the heaters as well as chilling.

We have SS 304 tubular heater for milk heating and chilling and for holding and transfer - we planned same SS 304 tubes.

But we have been informed by a supplier to use UPVC and CPVC food grade for the milk flow except for heating and chilling portion) for hold time, if temp. is less around 70-80 deg.C,) transfer to silo or packing machine.

I searched in google and also gone through the web link of the supplier. The temp. required will go up to 90 Deg.c with out holding time where as the cpvc temp. limit is 80 deg.

As I have no knowledge about usage of UPVC or CPVC I seek the advise of CR4 Members who have more experience in dairy.

The capacity of dairy is 2000 litres of milk per hour.

Any other detail required< I will be glad to furnish.

Thanks,

DHAYANANDHAN.S

Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Guru

Join Date: Oct 2008
Posts: 39909
Good Answers: 1588
#1

Re: Material for Pipe Milk dairy - Milk transfering to Silo/Packing machine

11/04/2017 9:40 AM

UPVC is simply rigid PVC with no plasticizers added.

CPVC is chlorinated PVC and it is more flexible and withstands higher temperatures.

It is commonly used in chemical processes.

I know nothing about its use in dairies, I worked in chemical processing where we used both.

Register to Reply
Guru
Engineering Fields - Mechanical Engineering - New Member

Join Date: May 2008
Location: CHENNAI, TAMIL NADU, INDIA.
Posts: 1794
Good Answers: 62
#2
In reply to #1

Re: Material for Pipe Milk dairy - Milk transfering to Silo/Packing machine

11/04/2017 12:14 PM

Thank you Mr. lyn for your reply. Let me wwait for a day or to to see other members views.

Thanks,

dhayanandhan.s

Register to Reply
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 13569
Good Answers: 155
#13
In reply to #1

Re: Material for Pipe Milk dairy - Milk transfering to Silo/Packing machine

11/06/2017 1:53 PM

I think CPVC is not allowed in contact with potable water or food, due to leaching?

PVDF (Kynar) would be a preferred material in such a case.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 19990
Good Answers: 750
#3

Re: Material for Pipe Milk dairy - Milk Transferring to Silo/Packing machine

11/04/2017 12:21 PM

I would be very reluctant to use CPVC so close to its maximum usable temperature. At the very least I would question the supplier specifically about the temperature.

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 19288
Good Answers: 1129
#4

Re: Material for Pipe Milk Dairy - Milk Transferring to Silo/Packing Machine

11/04/2017 12:37 PM

CPVC is good up to and including 200°F according to the manufacturer....Any pipe material used in dairy processing must be certified for use....

USDA guidelines

CPVC pipe specs

http://edis.ifas.ufl.edu/pdffiles/fs/fs11900.pdf

__________________
Life is like riding a bicycle. To keep your balance you must keep moving. A.E.
Register to Reply
Guru
Hobbies - CNC - New Member Hobbies - DIY Welding - New Member Engineering Fields - Electromechanical Engineering - New Member

Join Date: Aug 2007
Posts: 18984
Good Answers: 336
#6
In reply to #4

Re: Material for Pipe Milk Dairy - Milk Transferring to Silo/Packing Machine

11/04/2017 12:41 PM

You also need to included the more stringent 3A requirements to be USDA 3A approved. also yours specification is 16 years old, may need an updated on.

also it a good rule of thumb, but it may not cross over to other country's governing bodies.

__________________
phoenix911
Register to Reply
Guru
Hobbies - CNC - New Member Hobbies - DIY Welding - New Member Engineering Fields - Electromechanical Engineering - New Member

Join Date: Aug 2007
Posts: 18984
Good Answers: 336
#5

Re: Material for Pipe Milk Dairy - Milk Transferring to Silo/Packing Machine

11/04/2017 12:38 PM

Is you pasteurized a HTST (High Temperature/Short Time)?

keep in mind, the material may be ok for transfer, but not as a holding tube for pastuerization

Challenge your suppliers... have them supply you with the documentations.

And the documentation not only include it can do that, but also documentations the governing santitary approvals for this use.

the pastueurizers I've design, I always used Stainless 304/316. If for anything, it durability as well as sanitary.

the pasteurizer you listed is relatively small one. Also where you are, do you have new equipment inspectors for sanitary equipment?

__________________
phoenix911
Register to Reply
Participant

Join Date: Mar 2007
Posts: 3
#7

Re: Material for Pipe Milk Dairy - Milk Transferring to Silo/Packing Machine

11/05/2017 1:38 AM

As I remember all PET are prohibited to be used above 25 deg C. Because all plastics release Antimony (Sb) (Dioxins & Bisphenol) & release in creases as temperature increases.

Antimony is classified as a possible carcinogen to humans by the International Agency for Research on Cancer. Long-term exposure to elevated antimony can also lead to increased blood cholesterol and decreased blood sugar.

So for foods or milk processing SS 304/316 is best and safe option.

Register to Reply Off Topic (Score 5)
Guru

Join Date: Oct 2008
Posts: 39909
Good Answers: 1588
#10
In reply to #7

Re: Material for Pipe Milk Dairy - Milk Transferring to Silo/Packing Machine

11/05/2017 10:17 AM

PET was never mentioned, until you brought it up.

The subject is PVC.

Register to Reply Off Topic (Score 5)
4
Guru

Join Date: Dec 2010
Location: North West England
Posts: 925
Good Answers: 116
#8

Re: Material for Pipe Milk Dairy - Milk Transferring to Silo/Packing Machine

11/05/2017 7:38 AM

The dairy pipes will be cleaned after each production run at a much higher temperature than the milk temperature. Cleaning usually comprises a cold water rinse, then a hot caustic wash, then a hot water rinse followed by a cold water rinse. This will either be manual or by an automatic CIP (cleaning in place) system. Check the pipes selected will stand up to the cleaning regime before making a final choice as this will involve a much more arduous duty.

Register to Reply Good Answer (Score 4)
Guru
United Kingdom - Member - New Member

Join Date: Aug 2010
Location: Resting under the Major Oak
Posts: 4266
Good Answers: 176
#9
In reply to #8

Re: Material for Pipe Milk Dairy - Milk Transferring to Silo/Packing Machine

11/05/2017 8:26 AM

That would be my concern.

Having worked in the food industry firstly in engineering and then production management the hygiene clean down was rigorous. Corrosive chemicals and high temperatures aren’t going to be conducive for use with many forms of plastic piping.

__________________
Pessimists are rarely disappointed.
Register to Reply Score 1 for Good Answer
Guru

Join Date: Dec 2010
Location: North West England
Posts: 925
Good Answers: 116
#12
In reply to #8

Re: Material for Pipe Milk Dairy - Milk Transferring to Silo/Packing Machine

11/06/2017 5:27 AM

Regulations in the UK require regular visual hygiene inspections of the inside of dairy pipework, vessels, pumps and valves. To achieve this the pipes must be easy and quick to disassemble and reassemble so it is common to fit Triclover™ joints (lots of manufacturers make these fittings under different names and I quoted this one only so you can find it quickly on the web). All the valves, pumps and tanks can be specified to come pre-fitted with these joints and attaching them to the pipe work just needs a butt weld and the inside surface grinding and polishing smooth to remove any ridges or pin holes where bacteria might lodge. The pipe welds can be done away from site in a clean (clear of possible mild steel contamination) welding shop and this allows for controlled lower cost fabrication. On site the pipes are locked together using a clamping collar with a gasket inserted. Gaskets should be replaced each time the pipe is reassembled. (Gaskets £0.50 each last time a purchased some)

While the same regulations may not be in place yet covering your dairy it is only a matter of time before they will become mandatory. Why not be forward thinking with your design.

Register to Reply
Guru

Join Date: Apr 2015
Location: NYC until mid 2015, currently NC
Posts: 615
Good Answers: 8
#11

Re: Material for Pipe Milk Dairy - Milk Transferring to Silo/Packing Machine

11/05/2017 9:26 PM

"...we have been informed by a supplier..."

It appears that the supplier to whom you refer is looking to make a sale, and might not have been aware of the condition where the temperature required will go up to 90 Deg.C.

While I have been away from sanitary applications for several years now, I do not ever recall seeing anything other than stainless steel used in such piping.

While the initial cost may be higher, overal, you will probably recoup part of any expenditure in the long run.

About 45 years ago, I had to design a replacement tank, and chose to make all parts of 316 SS except for the external saddles and top ring(also external); my boss thought I was crazy, but signed off on the expenditure,

Shortly after, corporate restructuring resulted in my boss and I, among many others, being laid off.

I visited the plant about a year later, and was informed that the tank had been left outside for almost the year, and the only parts that needed replacement were the saddles and top ring!

__________________
Good judgment comes from experience, and a lotta that comes from bad judgment.
Register to Reply
Guru
Hobbies - Fishing - Old Salt Hobbies - CNC - New Member United States - US - Statue of Liberty - New Member

Join Date: Mar 2007
Location: Rosedale, Maryland USA
Posts: 5213
Good Answers: 269
#14

Re: Material for Pipe Milk Dairy - Milk Transferring to Silo/Packing Machine

11/06/2017 3:57 PM

The lines in the family dairy farm for milk transfer were glass. Was told it was of a clear material so that you could see that it was clean. That no sediment had build up on the inside. Part of the sanitation process was to flush it with really hot water. As that was almost fourty years ago can't remember the temperature of the water. Also all the turns were done with sweep elbows. Which would allow the use of a scrubbing shuttle cock to be circulated if there was sediment build up.

That being said there are clear pvc pipes that are FDA approve for the application. You will need to get temperture specs from manufacture. As those are all different depending on the application.

__________________
Life is not a journey to the grave with the intention of arriving in a pretty, pristine body but rather to come sliding in sideways, all used up and exclaiming, "Wow, what a ride!"
Register to Reply
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 13569
Good Answers: 155
#15
In reply to #14

Re: Material for Pipe Milk Dairy - Milk Transferring to Silo/Packing Machine

11/06/2017 4:51 PM

Just what I want, PVC monomer in my milk! No wonder I am sick!

Glass is better, PVDF is better also, but no clear version I am aware of.

Pyrex is the best, I suppose.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Guru

Join Date: Jul 2012
Location: Madison, WI.
Posts: 1036
Good Answers: 45
#16

Re: Material for Pipe Milk Dairy - Milk Transferring to Silo/Packing Machine

11/07/2017 10:14 AM

In Wisconsin, the standard for dairy is Stainless Steel of 304 grade or better with food grade welds.

__________________
Knowing is the end result of learning, not believing.
Register to Reply
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 13569
Good Answers: 155
#17
In reply to #16

Re: Material for Pipe Milk Dairy - Milk Transferring to Silo/Packing Machine

11/07/2017 11:47 AM

Yes, OK, but how do you tell if the inside of the pipe is not coated with milk stone, or fouling?

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Guru

Join Date: Jul 2012
Location: Madison, WI.
Posts: 1036
Good Answers: 45
#18
In reply to #17

Re: Material for Pipe Milk Dairy - Milk Transferring to Silo/Packing Machine

11/07/2017 12:38 PM

SANPC (sanitation process controls) A combination of CIP, Break down and clean, videographing, physical inspection and Swabbing and sampling followed by steam exposure to sterilize. It is a Validated, highly documented, and very rigorous regimen.

__________________
Knowing is the end result of learning, not believing.
Register to Reply
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 13569
Good Answers: 155
#19
In reply to #18

Re: Material for Pipe Milk Dairy - Milk Transferring to Silo/Packing Machine

11/07/2017 1:04 PM

OK, and I expect this is also time-tested by many years experience with.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Guru
Hobbies - CNC - New Member Hobbies - DIY Welding - New Member Engineering Fields - Electromechanical Engineering - New Member

Join Date: Aug 2007
Posts: 18984
Good Answers: 336
#20
In reply to #17

Re: Material for Pipe Milk Dairy - Milk Transferring to Silo/Packing Machine

11/07/2017 3:55 PM

The lines need to be able to taken apart... What's allowable is you have a straight run and a elbow, then you need a clamp connection. That what you can see the full internals... except inside side of elbow.

Otherwise what you can do (if the equipment inspector lets you), you'd need a borescope to check for the condition inside the pipe...

In a plant, normally there are samples taken, and when the bacteria count goes up, then they investigate.

But on a holding tube on a pasteurizer, see picture below, we had always did a full process weld, with back gassing.

We needed to use a borescope to verify the internals,... welds basically.

__________________
phoenix911
Register to Reply
Guru
Engineering Fields - Mechanical Engineering - New Member

Join Date: May 2008
Location: CHENNAI, TAMIL NADU, INDIA.
Posts: 1794
Good Answers: 62
#21
In reply to #20

Re: Material for Pipe Milk Dairy - Milk Transferring to Silo/Packing Machine

11/08/2017 10:04 AM

I thank all the CR4Vmembers who have shared their views on this topic.

We have decided to use SS 304 material where ever milk is flowing.

Once again I thank all the CR4 members.

DHAYANANDHAN.S

Register to Reply Score 1 for Good Answer
Register to Reply 21 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

Abdul Rahim (1); Casper71 (1); dhayanandhan (2); James Stewart (4); jhhassociates (2); lyn (2); ozzb (1); phoenix911 (3); rashavarek (2); SolarEagle (1); TonyS (1); Tornado (1)

Previous in Forum: Precise Duty Cycle of PWM   Next in Forum: Top Eco Fluid Activation Device

Advertisement