How does a steam trap work?
The operation of a steam trap is based on the physical difference between steam and condensate. Depending on the type, the steam trap responds to temperature, pressure or density. When condensate is present, the trap opens and discharges it. In the presence of steam, it closes automatically. This process runs continuously and adapts to varying process conditions.
There are three operating principles:
- Mechanical – responds to density difference (float-controlled and inverted bucket steam trap)
- Thermodynamic – responds to pressure and velocity differences (thermodynamic steam trap)
- Thermostatic – responds to temperature difference (thermostatic and bimetal steam trap)
What types of steam traps are available?
In industrial applications, several types of steam traps are used, each tailored to specific pressure and load conditions.
Thermodynamic steam trap
Operates on pressure and velocity differences. Suitable for higher pressures and varying loads. Compact in design and low maintenance.
Float-controlled steam trap
Continuously regulates condensate discharge based on the float level. Used for constant loads and processes requiring continuous drainage.
Thermostatic steam trap
Responds to temperature differences between steam and condensate. Discharges condensate once it has cooled sufficiently. Suitable for lower pressures and heating applications.
Bimetal steam trap
Uses two metals with different expansion coefficients to automatically regulate discharge at temperature changes. Suitable for hard-to-reach installations.
Inverted bucket steam trap
Mechanical operation based on the presence of steam and condensate. Suitable for specific applications with higher pressures and contaminated condensate.
Membrane steam trap
Regulates discharge via pressure differences on a flexible membrane. Used in compact installations where space is limited.
Venturi steam trap
Uses flow effects for continuous discharge without moving parts. Applied where conventional steam traps are less suitable due to vibrations or extreme conditions.
Selection guide: which type suits your situation?
| Situation |
Recommended type |
| High pressure, varying load |
Thermodynamic steam trap |
| Constant load, continuous drainage |
Float-controlled steam trap |
| Low pressure, heating application |
Thermostatic steam trap |
| Hard-to-reach location |
Bimetal steam trap |
| Contaminated condensate, high pressure |
Inverted bucket steam trap |
| Compact installation |
Membrane steam trap |
| Vibrations or extreme conditions |
Venturi steam trap |
Select the right steam trap based on working pressure, medium and load, or request a quote directly via +31 26-3706830 or info@ebora.nl.
Applications of steam traps in industry
Steam traps are used in installations where steam is applied for heating, drying or process control. In heat exchangers, correct condensate drainage ensures stable heat transfer and prevents energy loss through steam leakage or condensate build-up. In steam turbines, steam traps contribute to consistent operation and a longer service life of the equipment.
In combination with
valve actuators and
ball valves, a controlled system is created in which pressure and temperature remain manageable. A Spirax Sarco steam trap is frequently used in processes requiring precise control and consistent performance, such as in the food industry, pharmaceutical production and the chemical industry.
What to consider when selecting a steam trap?
Selecting a steam trap starts with the process parameters of your installation. Choosing the wrong type results in energy loss through steam leakage or condensate build-up with the risk of water hammer.
Points to consider when selecting:
- Maximum working pressure and temperature of the system
- Type of load: continuous or variable
- Required discharge capacity in kg/h
- Start-up behaviour of the installation
- Maintenance and accessibility of the steam trap
Brands in the range
Ebora supplies steam traps from manufacturers with a proven track record in industrial applications:
- Spirax Sarco
- ARI-Armaturen
- Goetze Armaturen
- HELS
- Ebora
The selection focuses on applicability within existing installations and consistent performance under varying process conditions.
Frequently asked questions about steam traps
What is the difference between a thermodynamic and a float-controlled steam trap?
A thermodynamic steam trap operates on pressure and velocity differences and is suitable for higher pressures with varying loads. A float-controlled steam trap continuously regulates discharge based on the condensate level and is used for constant loads. The choice depends on your pressure, load profile and the required discharge frequency.
How do I recognise a defective steam trap?
A defective steam trap can be identified by steam loss through the discharge line, condensate build-up in the system or irregularities in pressure and temperature. A steam trap that remains continuously open loses steam and increases energy consumption. A steam trap that fails to open causes condensate build-up with the risk of water hammer.
When should I choose a Spirax Sarco steam trap?
A Spirax Sarco steam trap is the right choice when precise control, high reliability and extensive technical support are required. Spirax Sarco offers versions for virtually all pressure classes and applications, including steam turbines, heat exchangers and heating systems.
How often should a steam trap be inspected?
The inspection frequency depends on the application and type of steam trap. In most industrial installations, periodic inspection is recommended, at least annually. An undetected defective steam trap leads to energy loss and potential damage to equipment. Regular inspection extends the service life of your system.
