Metallurgy Specification - Bronze and PTFE

What is an "electricity butterfly"?

Bronze is metallic, electrically conductive, is able to be impregnated with oil for certain bearing applications, and (I think) has a higher PV (pressure/velocity) rating. Depending on the chemical environment, it may or may not be corrosion-resistant.

PTFE (Teflon™) is nonmetallic, electrically nonconductive, fairly self-lubricating, and corrosion-resistant to most chemicals; but (I think) has a lower PV rating as bearing/bushing material.

thank you for your information

I had asked cause i have a specification of electricity butterfly valve ,, and its bushing was Bronze and the contractor want to change it to Teflon ,,,

and i was confused cause i do not know the specification of the TEFLON

• "Teflon" is a product name. PTFE is the substance it is made from.
• "Polythene" is a product name. Polyethylene is the substance it is made from.

And so-on.

THANK YOU

Thanks, this is good additional information.

Here is one manufacturer's data on bearings/bushings of both types.

As I was thinking, bronze is "stronger" than PTFE. However, for a butterfly valve the velocity will be well below the capability of either material. Thus the pressure rating will be more important (bronze 4000 psi, PTFE 1100 psi in this example).

At first glance, bronze seems better, but if you have the valve size, line pressure, and bushing dimensions, PTFE may also be more than adequate for the stress imposed on the bushing. Corrosion resistance is the other criterion; what is the fluid to be conveyed in the piping?

Oops, I forgot temperature; that must be considered as well.

Temp. will not access 72~80 C 161~176 F

here is the info of the site

Max. flow rate is 450 m3/ hr

and the valve will be on the suction line which has 0.4 bar

and water will be inside the pipe and it is inslatalion

What is the pipeline size? Also, if you have this information, what are the dimensions of the bushing in the valve?

For now, I am still guessing a bit, but I think PTFE will be satisfactory.

Pipe size is 8"

and (electricity butterfly valve is new item) so i did not know the size may be will check any company but i think will not access 2" or 3"

Open a dialogue with a local valves distributor, who will be more than happy to help, especially if the valve is to become a new purchase item.

exactly the Bushing size is 2"