Series TDST Thermodynamic Steam Traps control steam and condensate movement to maximize removal of latent heat from steam for efficient system operation. The thermodynamic trap has cyclic on-off operation with a disk that is pushed open by incoming condensate and closes tightly when steam tries to escape. The compact design allows the steam trap to be mounted in any position and models available with an integral strainer remove the need for additional apparatus. When the trap is mounted vertically, it self-drains, making it freeze resistant. The trap also handles water hammer, superheat, is resistant to internal and external corrosion, and is easy to install. A hardened 316 SS disc is the only moving part in the trap ensuring long service life. Audible discharge cycling makes it simple to check steam trap operation.