Comparison of PTFE and PFA Lined Lug Butterfly Valves

Glad that you are interested in PTFE lined butterfly valve, VALTECCN will introduce the difference and comparison of advantages between PTFE and PFA different materials for you.

Both PTFE and PFA are fluoropolymers with excellent chemical resistance, high temperature resistance, abrasion resistance and non-stick properties. They can all be used as valve seat materials to improve the sealing performance and service life of the valve. However, there are some notable differences between them that affect their applicability in different working conditions.

First, PTFE and PFA are processed differently. PTFE is a powdery material that cannot be molded by conventional melt processing, but requires special processes such as compression molding or dip molding. PFA is a granular material that can be formed by melt processing such as injection molding or extrusion. As a result, PFA seats are more efficient and less costly to produce, while PTFE seats require more labor and equipment investment.

Second, the physical properties of PTFE and PFA are different. PTFE is more heat resistant and has a melting point of 327°C compared to 260°C for PFA. Therefore, under high temperature conditions, PTFE valve seats are better able to maintain their shape and dimensional stability, while PFA valve seats may deform or shrink. On the other hand, PFA has higher mechanical strength and toughness, and its tensile strength is 25-35 MPa, while that of PTFE is 20-30 MPa. Therefore, under high pressure or shock loads, PFA seats are more resistant to stress and deflection, while PTFE seats may crack or break.

Finally, PTFE and PFA have different electrical properties. PFA has a higher dielectric strength and dielectric constant of 40-60 kV/mm and 2.1-2.2, respectively, while the dielectric strength and dielectric constant of PTFE are 18-60 kV/mm and 2.0-2.1, respectively. Therefore, under the influence of electric field or static electricity, the PFA valve seat is more resistant to breakdown and discharge, while the PTFE valve seat may be damaged or aged.

To sum up, PTFE and PFA valve seats made of different materials have their own advantages and disadvantages, and are suitable for different working conditions. Generally speaking, in the environment of high temperature, low pressure, low frequency, no electric field or static interference, PTFE valve seat is more suitable; and in the environment of low temperature, high pressure, high frequency, electric field or static interference, PFA valve seat is more suitable.

If you want to know more about PTFE lined butterfly valve, please visit VALTECCN’s website: www.valteccn.com. VALTECCN is a professional PTFE lined butterfly valve supplier and manufacturer with many years of production experience and technical support. VALTECCN’s PTFE lined butterfly valve adopts high-quality PTFE or PFA valve seat material, and undergoes strict quality control and testing to ensure its reliable performance, durability and safety. PTFE lined butterfly valve of VALTECCN can meet your requirements for corrosion resistance, high temperature resistance, wear resistance, non-adhesion, etc. in various industrial fields.