PCTFE or CTFE (originally known as Kel-F*) has many of the properties similar to other fluoropolymers such as PTFE, FEP or PFA, but is mechanically superior in rigidity (does not deform easily), and has very low gas permeability .
PCTFE or CTFE (originally known as Kel-F*) has many of the properties similar to other fluoropolymers such as PTFE, FEP or PFA, but is mechanically superior in rigidity (does not deform easily), and has very low gas permeability . Its dimensional stability makes it attractive for use as a component of a structural part where the high temperature and chemical resistance of fluoropolymers is required. PCTFE shows high compressive strength and low deformation under load. However, its relative cost is one of the major considerations in its selection, since it is quite expensive.
The Steel Industry and Chemical Processing Industry have been using fluoropolymer tubing products from materials like PTFE and hoses for many years for transferring highly caustic or corrosive chemicals. More and more, PTFE tubing is replacing carbon and other metal piping that deteriorates rapidly. Now and for the future, PTFE will continue to serve the industry in critical applications.
PTFE Thermal Qualities:
PTFE tubing can withstand temperatures up to 680 °F for limited periods of time.* Under cryogenic conditions, PTFE remains strong down to -320 °F.
*Above 500 °F, mechanical properties become a limiting factor
PTFE Electrical Qualities:
PTFE tubing has superb electrical properties, indicated by a low dielectric constant of 2.1 between -40 °F and 480 °F within a frequency range of 5 Hz to 10 GHz.
PTFE tubing is also an excellent insulator with surface resistivity of 3.6 X 1012 ohms (even at 100% relative humidity).
Short time dielectric strengths range from 500 volts/mil (1 mil = 10-3 in) for thicknesses greater than 100 mils to 4000 volts/mil for very thin films.
Differences from PTFE
PCTFE is a homopolymer of chlorotrifluoroethylene (CTFE), whereas PTFE is a homopolymer of tetrafluoroethylene. The monomers of the former differs from that of latter structurally by having a chlorine atom replacing one of the fluorine atoms. Hence each repeating unit of PCTFE have a chlorine atom in place of a fluorine atom. This accounts for PCTFE to have less flexibility of chain and hence higher glass transition temperature. PTFE has a higher melting point and is more crystalline than PCTFE, but the latter is stronger and stiffer. Though PCTFE has excellent chemical resistance, it is still less than that of PTFE. PCTFE has lower viscosity, higher tensile strength and creep resistance than PTFE.
PCTFE is injection moldable and extrudable whereas PTFE is not.
So, I would say it depends on the application of the valve. Do you have temp/pressure limits? What fluid/vapor service is it in? Seems like it would be OK for the vast majority of applications where PTFE is used, but there are bound to be specific, niche applications where PTFE is required rather than PCTFE.
PTFE = polymerPCTFE = Kel-F
Both are suitable for use for ball valve seats. Big difference is the PCTFE is harder and has higher friction. Impact of both factors is that it tends to require more torque to turn the valve open and closed
PS: Contact us for PTFE finished products free sample
Post time: Sep-17-2017