Pressure Gauge Glycerine & Silicon

Dear Sir/Madam,

Thanks for your reply.

But i had some questions.

1. Heat degradation of the fluid. I wouldn't think silicone would degrade, though.

Yes,normal condition silcon shouldn't degrade.So i feel very confused.

Because we always use standard silcon,but the Glycerine & Silicon still become yellow.

2. Leakage of the working fluid past a seal.

We had check the oil become yellow gauge,but the material inside were normal,didn't have leakage problem.Only Glycerine & Silicon become yellow.

3. Leaching of some contaminate from a rubber seal inside the gauge.

Our rubber had already leach contaminate and change the color from black to ash sice we found the oil had become yellow problem.

But the problem still didn't get improve.

Dear Sir/Madam,

Our material didn't use EPDM.

Our material were include NBR,brass,iron,aluminum,SS304,and some loctite.

And we have test every part bathe by Glycerine & Silicon.

The oil didn't become yellow,but when i filled Glycerine or Silicon into gauge.

After helf of year or one year,the Glycerine or Silicon inside gauge always star become yellow.

I really don't know why.

Please offer us your suggest.

Best regards

David

Dear Sir/Madam,

Thanks for your reply.

1.If the Gauge housing have some humidity inside.

How should i improve this problem?

2.For Aluminium and Steel.

My dial was use Aluminium material and screw use steel material,but screw have coating nickel.

However,how can i prevent or improve oxidation condition?

3.Why the Glycerine also become yellow,and it's more serious than Silicon.

How can i prevent or improve this problem?

Please can give me some suggest.

Thank you

Best regards

David