Help with transparent food-grade tubular system and 3D parts

[annlee]

hello, this is the problem to solve:

I need a transparent food-grade PVC tubular system joined with "U" and "T" with more similar tubes, but also joined with custom 3D printer parts.

How to make this circuit?

Discussion is: should I use (A) mechanical joints or (B) PVC paste?

- I should use a tubular size of 50 or 63, since these are standard sizes compatible for the "U" and "T"

- I think there is no food-grade paste for PVC, should I go for A then?

- What 3D printer material to use to paste PVC with? and what paste?

Do you have any better ideas or suggestions? would you go for A or B then?

Thanks in advance

 

[hendersdc]

3D printed parts are not water tight and will not meet any kind of food grade cleanliness standard. They all have some level of porosity, you may be able to apply a sealant but will likely still have some leaks. That porosity is also impossible to clean and you will get stuff growing in it if your part comes in contact with food.

 

[btrueblood]

There is no "food grade standard" for Oatey or other manufacturers to meet, but there is NSF 51 certification for potable water, which is where I would start. NSF standards for food equipment vary in stringency, but for the most part you need clean, non-leaching materials that can be shown to be capable of being cleaned and sanitized by some method. Testing for this involves contaminatting the equipment with a nutrient broth containing e-coli, then cleaning per manufacturer's instructions, and then rinsing with fresh, uncontaminated broth and testing (incubating) for any bacteria left on the equipment that contaminated the rinse broth. And its as smelly and nasty a test as you could imagine.

 

[MikeHalloran]

I may have missed a meeting, but I think PVC is NOT approved for food contact, in any grade or any form.

Mike Halloran
Pembroke Pines, FL, USA

 

[Compositepro]

PVC is a very common food grade plastic. It is used in pipes for drinking water (which use glued joints) and as a cling wrap for food, and as transparent flexible tubing for beverages.

 

[MacGyverS2000]

For water, it's CPVC, not PVC (for completeness).

Dan - Owner

http://www.Hi-TecDesigns.com

 

[Compositepro]

CPVC is for hot water lines and may also be used for cold water. Regular PVC can be used for cold water.

 

[annlee]

thank you guys,

there are food-grade transparent PVC tubes:
-

http://tecno-products.com/producto/pvc-cristal/

-

http://www.mwmaterialsworld.com/es/tubo-rigido-de-pvc-transparente.html

and with 3D parts, you can use a 100% density, that should avoid liquid to pass through

anyways, dont you think guys I should assemble the PVC or other similar material with heat instead of using non-food-grade pastes or mechanical joints?

 

[MacGyverS2000]

CPVC is for hot water lines and may also be used for cold water. Regular PVC can be used for cold water.

We're both wrong/right, it seems. Depends upon the jurisdiction. Most allow for PVC for cold water supply, but many do not allow it for distribution. Building codes are too confusing these days.

Dan - Owner

http://www.Hi-TecDesigns.com

 

[hendersdc]

100% density will not eliminate the porosity issues, what you essentially get is tightly packed cylinders but they still have space between them.

 

[annlee]

I am doing it the easiest way:

a silicone food-grade flexible transparent tube and clamps, difficult to find here thought, since I only need 2ms and they can order only rolls of 20ms