How to Select a Rosemount Differential Pressure Transmitter for High-Temperature Applications?

Rosemount differential pressure transmitters are widely used in oil & gas, refining, power generation, boilers, steam and industrial process control.

For high-temperature applications, proper selection and installation are essential for reliable measurement.

1. Check Process and Ambient Temperature

The process temperature is not the same as the temperature around the transmitter.

Before selection, confirm:

* Process Temperature

* Ambient Temperature

* Process Pressure

* DP Range

For high-temperature media, the transmitter should be properly isolated from direct heat whenever possible.

2. Consider a Remote Seal

For high-temperature liquids, steam, corrosive or viscous media, a remote seal with capillary tubing can be a suitable solution.

The remote seal helps isolate the transmitter from direct exposure to high-temperature process media.

3. Pay Attention to Fill Fluid and Capillary Installation

The fill fluid used in the remote seal system must be suitable for the actual process temperature.

During installation:

* Avoid direct contact between capillary tubing and hot pipes

* Avoid sharp bends or mechanical damage

* Keep HP and LP capillaries as symmetrical as possible

* Minimize temperature differences between the two sides

Improper installation may cause temperature-related errors and zero shift.

4. Special Considerations for Steam Measurement

For high-temperature steam flow measurement, impulse lines and condensing pots are commonly used to reduce the temperature reaching the transmitter.

The HP and LP sides should have similar installation conditions to minimize hydrostatic and temperature-related measurement errors.

5. What Information Is Needed?

For proper Rosemount DP transmitter selection, customers should provide:

Transmitter Model + Process Temperature + Ambient Temperature + Process Pressure + DP Range + Medium + Remote Seal + Capillary Length

Conclusion

For high-temperature applications, selecting a Rosemount differential pressure transmitter requires more than simply checking the temperature rating.

Process temperature, ambient temperature, remote seal, fill fluid, capillary length and installation method should all be considered to achieve reliable and accurate measurement.