Spirax Sarco Thermodynamic Steam Traps

Thermodynamic steam traps combine simplicity, reliability, and efficient operation in a compact design. They work by using the pressure and velocity difference between steam and condensate to cycle open and closed. With only one moving part, they offer excellent resistance to wear and are highly suitable for high-pressure and outdoor installations. Their rugged construction and dependable performance make them a core component in modern steam distribution systems.

How do Thermodynamic Steam Traps work?

Thermodynamic steam traps operate using the natural energy within the steam itself.

When condensate enters the trap, it flows freely through the inlet and lifts the disc, allowing the cooler liquid to discharge.

As hotter fluid and flash steam reach the trap, the high velocity across the disc creates a pressure drop beneath it. At the same time, steam pressure builds in the chamber above the disc. This pressure differential forces the disc down onto its seat, closing the trap tightly.

The trap remains shut while steam is present, preventing live steam from escaping.

As the trapped steam above the disc cools and condenses, the pressure in the chamber falls. This allows the disc to lift again, reopening the trap and releasing the next batch of condensate. The result is a rapid, self-regulating cycle that responds automatically to changing conditions.

With only one moving part, thermodynamic steam traps are exceptionally robust, highly resistant to wear, and capable of operating reliably at high pressures and in harsh outdoor environments.

This simplicity is what makes them a core choice for mains drainage, tracing lines, and demanding industrial steam systems.

One Disc. Total Control

Spirax Sarco Thermodynamic Steam Traps harness the energy of steam itself to regulate condensate flow, opening when water is present and sealing instantly as steam arrives. With just a single moving part, they deliver exceptional durability, high-pressure performance, and rock-solid reliability—making them the perfect choice for outdoor installations, steam mains, and the toughest industrial environments.

Spirax Sarco Thermodynamic Steam Traps use the energy of steam itself to control condensate discharge, cycling open and closed with precision and reliability. With just one moving part, they thrive in high-pressure, outdoor, and demanding industrial environments—delivering dependable performance, minimal maintenance, and efficient steam system protection where it matters most.

Frequently Asked Questions

A thermodynamic steam trap uses the pressure and velocity difference between steam and condensate to control discharge. It opens on condensate and closes tightly when steam reaches the trap.

Condensate lifts the disc and flows out. When hot steam arrives, pressure builds above the disc and forces it shut, preventing live steam loss until the cycle repeats.

They have only one moving part. This simple design reduces wear, resists dirt, and delivers long service life in harsh conditions.

They are commonly installed on steam mains, tracing lines, outdoor pipework, and high-pressure systems.

Yes. They prevent live steam from escaping while discharging condensate efficiently, reducing energy waste across the system.

Absolutely. Many models are designed for high-pressure and superheated steam applications.

Yes. Their compact, rugged construction makes them ideal for exposed installations and extreme environments.

No. They operate in rapid cycles, opening to release condensate and closing when steam is present.

They are typically designed to fail open, allowing condensate to escape and preventing flooding of the system.

Many models feature replaceable seats and serviceable internals, allowing in-line maintenance.

They vent air during start-up, though not as rapidly as thermostatic designs. This is usually sufficient for mains drainage and tracing.

They combine simplicity, durability, and proven performance. With a wide range of models for every pressure and environment, they provide dependable condensate control across modern steam systems.