Teflon PTFE is also known as polytetrafluoroethylene. Teflon PFA is also known as soluble polytetrafluoroethylene. Many valve purchases are not quite clear which is better corrosion resistance for butterfly valves using PTFE and PFA? What are the advantages and disadvantages of each? Difference in temperature resistance, which is cheaper?

Different in nature

1. PFA: a copolymer of a small amount of perfluoropropyl perfluorovinyl ether and polytetrafluoroethylene.
2. PTFE: a polymer compound formed by polymerization of tetrafluoroethylene.

Different characteristics

PFA characteristics

(1) Crystal material, low moisture absorption. It can be processed into products by thermoplastic processing methods.

(2) Poor fluidity, easy to decompose, and corrosive gas is generated during decomposition. The molding temperature does not exceed 475°C, the mold is heated to 150-200°C, and the pouring system has little resistance to material flow.

(3) Translucent pellets, injection molding and extrusion molding. Molding temperature is 350-400℃, 475℃ and above are easy to cause discoloration or blistering. Pay attention to the difficulty of demolding.

(4) Due to the corrosion effect of molten material on metal, long-term production requires chrome plating on the mold.

PTFE characteristics

(1) High temperature resistance: long-term use temperature 200~260℃;

(2) Low temperature resistance: softer at -100℃;

(3) Corrosion resistance: resistant to aqua regia and all organic solvents;

(4) Weather resistance: the best aging life of plastics;

(5) High lubrication: with the smallest coefficient of friction (0.04) among plastics;

(6) Non-sticky: It has the smallest surface tension among solid materials without adhering to any substance.

Summary

The biggest difference is that PFA is easier to process and more expensive than PTFE, but in practice PTFE has better corrosion resistance and is also resistant to high temperatures.

VALTECCN is an industrial manufacturer and supplier of butterfly valves in China, producing PTFE and PFA lined butterfly valves, if you have any questions about butterfly valves or request for quotation, please feel free to contact us.