Quick answer
Disc springs may lose load at high temperature because the material relaxes under heat and compression. The spring can provide less force over time even if the installation height does not visibly change.
This matters in valve live loading, flange sealing, thermal equipment and bolted joints where retained preload is more important than the first assembly load.
What controls relaxation risk
Important factors include temperature, holding time, working stress, material strength, heat treatment, surface condition and media. A short heat exposure is different from long-term preload retention at elevated temperature.
Spring steel, stainless steel, precipitation-hardening stainless steel, nickel alloys and cobalt-based alloys all have different limits and cost implications.
How to screen high-temperature materials
For short-term heat exposure, the material choice may be simpler. For long-term valve preload, sealing compensation or corrosive media, relaxation resistance and corrosion resistance should be checked together.
Common directions include precipitation-hardening stainless steel, hot-work steels, Inconel X-750, Inconel 718, Nimonic 90 and other heat-resistant alloys.
Frequently Asked Questions
Why do disc springs lose load at high temperature?
Stress relaxation is a common reason. Under heat and compression, the spring load may decrease over time.
Is maximum service temperature enough for material selection?
No. Holding time, working stress, media, cycling and surface condition also matter.
What materials are used for high-temperature disc springs?
Common directions include precipitation-hardening stainless steel, hot-work steels, Inconel X-750, Inconel 718, Nimonic 90 and other heat-resistant alloys.
Need FeTech to review your disc spring application?
Send the drawing, stack envelope, load target, temperature, media and quantity. Our team can check material direction, stack logic and quotation readiness.
- DIN 2093 replacement or custom geometry
- Valve, flange, actuator and severe-service stacks
- Material review for stainless, Inconel, Hastelloy, titanium or heat-resistant steel
Final geometry, fatigue life, K4 source, friction and support-face conditions still require engineering confirmation.