PCTFE gaskets
When a flange has to stay sealed under bolt load, resist creep over time and hold a reliable barrier against gas and moisture, PCTFE is the fluoropolymer engineers reach for. Its rigidity and high resistance to cold flow keep a gasket dimensionally stable long after installation, where a softer polymer would relax and lose its seal. Vanéflon produces PCTFE gaskets to your drawing, cut and machined to tight tolerances from compression-moulded sheet and plate, ready for cryogenic, high-purity and aggressive-media service.
You will sometimes see this material referred to by its trade names Kel-F, Neoflon or Voltalef. Whichever your drawing specifies, it is the same base polymer, and Vanéflon can supply it as a finished gasket, a cut blank or semi-finished stock.
What is PCTFE?
PCTFE stands for polychlorotrifluoroethylene, a high-performance fluoropolymer in the same family as PTFE. The difference lies in the molecule: PCTFE replaces one fluorine atom with chlorine, and that single change makes the material noticeably more rigid, harder and more dimensionally stable, with far lower gas and moisture permeability. For a gasket that has to hold its shape and its barrier under load, that combination is exactly what counts.
Why PCTFE for gaskets
In a flange or face seal PCTFE brings a set of properties that few materials match:
- High rigidity and resistance to cold flow, so the gasket holds its thickness and its seal under sustained bolt load instead of creeping out of the joint.
- Excellent cryogenic performance, keeping mechanical integrity down to extremely low temperatures where elastomer and fibre gaskets become brittle and fail.
- Outstanding gas and moisture barrier, with the lowest water vapour transmission rate of the common fluoropolymers.
- Near-zero moisture absorption, which keeps dimensions stable in humid and vacuum conditions.
- Very low outgassing, making PCTFE suitable for vacuum and aerospace sealing.
- Excellent chemical resistance to most acids, bases and oxidising agents, plus non-flammability with a high limiting oxygen index.
- Food contact compliant, meeting FDA and EU 10/2011 requirements.
Key properties of PCTFE gaskets
- Broad temperature resistance (–273 °C to +170 °C)
- Exceptional cryogenic performance and elasticity at extreme low temperatures
- The lowest water vapour transmission rate of all fluoropolymers
- Outstanding gas-barrier properties and near-zero moisture absorption
- Excellent chemical resistance across acids, bases and solvents
- High dimensional stability and strong resistance to cold flow (creep)
- Radiation resistance and stable electrical insulation
- FDA compliant and conform EU 10/2011 for food and pharmaceutical contact
Values are indicative and depend on grade. Download the PCTFE datasheet for the full technical detail, or ask our team for the grade that suits your application.
Dimensions, thicknesses and cut-to-size
Vanéflon supplies PCTFE gaskets across a wide range of diameters and thicknesses, cut and machined to your specification. Standard sheet and plate thicknesses are typically held in stock for fast delivery, while custom formats and near-net blanks are produced to order. Our cut-to-size service means you receive a gasket that is ready to install, with tight and repeatable tolerances on the sealing face and bolt pattern.
Tell us the outer diameter, inner diameter, thickness and bolt-hole pattern you need (or the flange standard you are sealing to), along with your application, and we will confirm availability, tolerances and lead time.
Cryogenic and high-purity sealing
PCTFE gaskets are at home wherever temperatures drop far below zero, gas permeation is critical, or purity cannot be compromised. Typical service includes liquid oxygen, liquid nitrogen and LNG handling, oxygen service, high-vacuum flanges and high-purity gas lines. Because PCTFE absorbs virtually no moisture and outgasses very little, it also seals reliably in vacuum and high-humidity environments where other gasket materials would take up moisture or contaminate the system.
Applications of PCTFE gaskets
PCTFE gaskets are machined and fabricated wherever reliable, low-permeation sealing is non-negotiable:
- Cryogenics and energy: flange gaskets and seals for liquid oxygen, liquid nitrogen and LNG, where low-temperature stability is essential.
- Aerospace: low-outgassing gaskets and sealing components across extreme temperature swings.
- Semiconductor: high-purity gas-line and vacuum gaskets where contamination cannot be tolerated.
- Chemical processing: flange gaskets for aggressive acids, bases and oxidising media.
- Pharmaceutical and life science: moisture-barrier and sterile-contact gaskets backed by food and pharma compliance.
Talk to our specialists about your application
Not sure PCTFE is the right fit? Share your temperature, media and sealing conditions, and we’ll help you specify the right solution.
PCTFE gaskets vs. other fluoropolymer seals
Compared to PTFE and PFA, PCTFE is more rigid and dimensionally stable, with a significantly lower water vapour transmission rate. While PCTFE is more expensive than standard fluoropolymers, it remains indispensable where gas permeation, cryogenic stability or moisture ingress would compromise the seal.
For applications that don’t require these extremes, our full range of sealing solutions offers cost-effective alternatives.
PCTFE gasket or PTFE gasket?
The two are often considered together, and the choice comes down to the joint. A PTFE gasket is soft and conformable, which makes it forgiving on imperfect flange faces and lower in cost, but it is prone to cold flow and creep under sustained load. A PCTFE gasket is harder and far more resistant to creep, so it retains bolt load and holds a tight seal over time, and it performs better at cryogenic temperatures with a lower gas barrier. For precise, rigid joints in cold, high-purity or low-permeation service, PCTFE is the stronger choice. If you are not sure which fits your flanges and conditions, get in touch and we will advise.
Why customers choose Vanéflon for PCTFE gaskets
High-quality products
Thanks to our extensive knowledge of high-performance plastics and the continuous monitoring by technical experts, we possess the necessary know-how from powder to final product.
Excellent service & support
We strive to have a one-on-one relationship with our customers. The Vanéflon team is always ready to answer all of your questions and to guide you in projects tailored to your company’s needs.
Cost efficiency
We analyse the needs of our customers to provide the most efficient solution possible.
Delivery reliability
We deliver as promised with flexible VMI systems to offer seamless support to the logistical processes of our customers.
Frequently asked questions
Request a quote
Looking for a reliable partner for PCTFE gaskets? Vanéflon supports you from material choice through to the finishing of the most complex sealing components.
Request a quote or reach out to our team, and we will come back with the right solution, tolerances and lead time.
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