Hello 1

[bao2ye]

Can anybody tell me what silicon free butterfly valve means?

free silicon means:

no silicon content in rubber seat?
no silicon in paint?
no silicon in grease?
no silicon in the metal?

I heard that silicon free butterfly valve should be used in Auto industry? What is the reason?

Thanks

 

[zdas04]

Just for your information, many people in these fora do not respond to threads with titles like "Help", or "Hello". If you want a meaningful answer to your question, I would suggest that you red flag your own post and ask the management to change the title to something that is more descriptive.

David

 

[bao2ye]

OK, Thanks David.

 

[JLSeagull]

Assume that silicon is not compatible with the contained fluid. Perhaps the requirement pertains to the soft goods only. However, as HF eats glass, silicon might not do well in HF service either.

 

[ApC2Kp]

bao2ye,

The auto industry may have concerns about silicone rubber (poly-siloxane) which has poor rating on hydrocarbon exposure (aromatic and aliphatic), and only fair rating on oil and gasoline exposure.
The silicone rubber has good properties for resisting water absorption, and for electrical insulation, but that may not be important for valve peformance to them.
Nitrile / Buna-N rubber valve seat probably is acceptable to auto industry.

 

[TenPenny]

I had some association years ago with a valve manufacturer, I remember hearing about all the valves sold to the GM plant in Ste Therese, outside of Montreal, for their new paint system. Then I heard there were 'issues' with the lubricants used to assemble the valves. Then I read about all of the GM cars where the paint was peeling off the bodies in large sheets, after only a few months.

I know, making assumptions is dangerous, but I assumed these things were related. Draw your own conclusions.

 

[bao2ye]

Thanks Tenpenny.

 

[bcd]

Hello,

TenPenny is correct. Normally Silicone free means that there is no Silicone lubricants used in the assembly of the product. Even the smallest amount of Silicone can ruin a lot of paint or photographic film. On paint, it can prevent adhesion and causes a defect called "fish eyes".

You will see the requirement for "Silicone Free" applied not only to the valve, but sometimes to the plant the product is manufactured in. It is that big of a problem.

There are tests you can do to verify your cleaning procedures are effective. In many cases, the end user will test the product again before they let it into their factory.

bcd

 

[roydm]

While working for Volkswagen, I ordered half a dozen tubes of silicone sealant for waterproofing joints. When it arrived I was told "Silicone screws up the painting" Good thing was I got to take the silicone home.
Roy