Kammprofile & Graphite Gaskets for High-Temperature Service
Above 400°F, elastomers are gone and PTFE is near its ceiling — high-temperature sealing belongs to flexible graphite and the metal-cored gaskets that carry it. Two products cover most of this territory: graphite sheet for moderate duties and kammprofile gaskets for the joints that keep leaking.
Flexible Graphite: The High-Temp Workhorse
Flexible graphite seals steam, hot oil, and hydrocarbons to roughly 850°F in oxidizing atmospheres (far higher in inert service). It conforms to imperfect flanges at modest bolt loads and recovers well through thermal cycles. Two specification notes matter: choose reinforced grades (stainless foil or tang insert) for handling strength and blowout resistance, and specify oxidation-inhibited, low-chloride graphite (under 50 ppm leachable chloride) for stainless steel systems and nuclear/steam service.
What a Kammprofile Adds
A kammprofile (camprofile) gasket bonds graphite facing layers to a serrated solid metal core. The grooved core concentrates bolt stress into the soft facing, producing a tight seal at lower bolt loads than spiral wound — while the solid core makes blowout essentially impossible and gives excellent recovery through thermal cycling. That combination is why kammprofiles have become the default for heat exchanger girth flanges, hot cycling services, and any joint with a leak history.
Kammprofile vs Spiral Wound
| Factor | Spiral wound | Kammprofile |
|---|---|---|
| Seating stress | Higher | Lower — seals weak/large flanges |
| Thermal cycling | Good | Excellent |
| Blowout resistance | Good (with rings) | Outstanding (solid core) |
| Reusability of core | No | Core can often be refaced |
| Cost | Lower | Higher upfront, lower lifecycle |
Where Each Belongs
Use graphite sheet for Class 150/300 steam and hot water, manways, and equipment covers. Use kammprofile for heat exchangers, Class 300–900 hydrocarbon flanges with thermal cycling, large-diameter joints where achieving spiral wound seating stress is difficult, and problem flanges you're tired of re-torquing. For grooved RTJ flanges, stay with ring joints.
Spec It Once, Seal It Once
We supply graphite sheet gaskets cut to size and kammprofile gaskets to standard ASME dimensions or custom drawings, cores in 316L and higher alloys. Send flange size, class, media, and temperature through the quote form above — pricing and lead time in 1–2 business hours.