Steam Traps

Bimetallic Steam Trap Station: Components, Benefits and Installation

Explore the components, benefits and correct installation of steam trap stations that combine a bimetallic steam trap, isolation valves and test fittings in one assembly.

ORFA Technical TeamUpdated: Oct 30, 20263 min read

Bimetallic steam trap station with isolation valves

Removing condensate from steam systems without losing steam is critical for efficiency and safe operation. However, a steam trap installed on its own usually means shutting down, draining and often dismantling the line for maintenance or fault-finding. A bimetallic steam trap station combines a bimetallic steam trap with isolation valves, a pipe connector and test fittings in one assembly, making installation, checking and maintenance much easier.

This article covers the station components, how a bimetallic trap works, the benefits of using a station and key installation points.

Components of a Bimetallic Steam Trap Station

Bimetallic steam trap: a thermostatic trap that discharges condensate according to its temperature.
Isolation (stop) valves: usually piston valves at the station inlet and outlet; they isolate the trap for maintenance.
Pipe connector: connects the trap to the pipework and allows the trap to be replaced without dismantling the line.
Test and drain valves (optional): used to drain the line and check that the trap is working.

How Does a Bimetallic Steam Trap Work?

The bimetal element is made of two metals with different coefficients of thermal expansion. As temperature changes, the two metals expand at different rates, so the element bends and moves the valve:

Cold condensate and air: the element is flat and the valve is open; condensate and air are discharged.
Hot condensate and steam: as temperature rises, the element bends and closes the valve, preventing steam loss.
Discharge behaviour: condensate is discharged once it has cooled somewhat below saturation temperature, so part of its sensible heat is used in the system.

Benefits of Using a Station

Easy maintenance: the isolation valves let the trap be isolated without shutting down the main line.
Quick replacement: the pipe connector allows the trap to be changed without cutting or dismantling pipework.
Easy fault-finding: the test valve makes it quick to check whether the trap is working correctly.
Compact, standardised installation: all components in one assembly shorten installation time and standardise practice across the plant.
Durability: bimetallic traps withstand water hammer and harsh operating conditions.

Applications

Drainage of steam mains and distribution lines
Steam tracing lines and steam jackets
Dryers and presses
Irons
Heat exchangers

Tip: Because a bimetallic trap discharges condensate after some subcooling, the trap type for applications such as heat exchangers, where condensate must not back up on the heating surface, should be selected according to load and temperature conditions. Choose the pressure rating and materials to suit the line’s operating conditions.

Installation and Maintenance

Install the station below the drain point so condensate can flow to it by gravity.
A strainer upstream of the trap protects the valve seat from dirt.
Install according to the flow-direction arrow.
Check trap operation periodically using the test valve.

Frequently Asked Questions

How does a steam trap station differ from a single steam trap?

A station supplies the trap together with isolation valves, a pipe connector and test fittings, so the trap can be checked and replaced without shutting down the main line or dismantling pipework.

Why are the stop valves in the station piston valves?

Piston valves provide tight, low-maintenance shut-off on steam and condensate lines.

Where are bimetallic steam trap stations used?

On steam main drainage, tracing lines, steam jackets, dryers, presses, irons and heat exchangers.

Conclusion

Bimetallic steam trap stations make condensate removal reliable while significantly reducing maintenance and fault-finding time. See other station types on our Steam Trap Stations page, or contact the ORFA sales team for help with selection.

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