Steam Conditioning Valves – Features, Advantages & Applications

Apr 6, 2024

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John Mulindi

in Process Plants Instrumentation

Contents

1 The Work of Steam Conditioning Valves & Why they are used in Industrial Processes
2 Steam Conditioning Valves
3 Typical Applications of Steam Conditioning Valves

The Work of Steam Conditioning Valves & Why they are used in Industrial Processes

Typically in an industrial set up, it may be necessary downstream of the main process application of superheated steam to reduce its pressure and temperatures to enhance the process efficiency, protect the equipment or perform other processes. This can be accomplished using a control valve to reduce the steam pressure and a desuperheating nozzle to reduce the steam temperature. Whereas this typical setup will often perform the function to an acceptable standard, it may also require longer than necessary straight pipe lengths, lead to less accurate temperature control, limit the total steam temperature reduction, and limit the total range of process conditions in which the system can acceptably perform the desired function. On the other hand, we can avoid these issues by using a steam conditioning valve (also called a steam converting valve or steam desuperheating valve) which combines the steam pressure control valve with the desuperheater in one unit. In other words, the steam conditioning valve is used to simultaneously reduce the steam pressure and temperature to the level required for a given application. Advantages of using a steam conditioning valve as a combined system are superior temperature control, maximum turndown as well as reduced space and construction cost owing to the compact design.

Steam Conditioning Valves

As aforementioned, a steam conditioning valve combines a steam pressure reducing control valve with a desuperheating system in one unit. The steam pressure or flow rate is controlled by the position of the plug in the steam conditioning valve while a water control valve regulates the flow of the injected cooling water and thus the temperature.

Figure 1.0 Steam conditioning control loop

The steam conditioning valve typically employs high performance, pneumatic piston actuators in combination with a digital valve controller to achieve full stroke in less than 2 seconds while at the same time maintaining highly accurate step response.