Ensuring Reliable Boiler System Performance
For industrial and commercial operations, steam purity is more than a quality metric—it’s a performance and safety imperative. Contaminants carried over in steam can damage critical equipment, reduce system efficiency, and increase maintenance costs. Accurately measuring steam purity enables facilities to protect assets, meet operational goals, and stay compliant with industry standards.
Yet, measuring steam purity is inherently complex. Steam can exit the boiler in three phases—vapor, liquid, and solid carryover—each with different densities and behaviors. Without the right sampling and testing techniques, even advanced monitoring systems can produce misleading data.
At Watertech of America, Inc., our approach is grounded in precision and best practices—empowering our partners to take control of steam quality with confidence.
The Foundation: Proper Steam Sampling
The most critical step in measuring steam purity is obtaining a truly representative sample. Non-uniform distribution of contaminants in the steam header can lead to inaccurate readings unless sampling is carefully engineered.
Watertech recommends the use of sampling nozzles installed according to ASME and ASTM standards (ASTM D1066). Placement, construction, and flow rate must all align with isokinetic sampling principles—meaning the steam velocity entering the nozzle matches the main steam line velocity. This ensures a proportional capture of particulates, dissolved solids, and other carryover materials.
Poor sampling setups can lead to underreported contamination levels, risking downstream equipment damage and compliance failures.
Methods of Steam Purity Analysis
Once a representative sample is secured, there are several analytical methods available to assess purity—each with specific advantages and limitations.
Gravimetric Method
This traditional technique involves condensing and evaporating the steam sample, then weighing the remaining solids. While theoretically accurate, it lacks the sensitivity needed for modern systems. The method is too slow and imprecise for measuring low-level contamination typical in well-managed operations.
Conductivity Measurement
Conductivity is a popular method for routine monitoring due to its ease and responsiveness. However, conductivity readings capture both dissolved solids and volatile substances like ammonia and carbon dioxide—leading to potential overestimation of true contaminant levels.To improve accuracy, specialized equipment is available:
- Powell-McChesney Degassing Condenser: Measures conductivity at the boiling point, minimizing interference from dissolved gases.
- Larson-Lane Analyzer: Uses ion exchange and degassing processes to isolate and measure dissolved solids with enhanced sensitivity.
These technologies offer greater precision, but results below 1 ppm of total carryover may still be difficult to correlate with high confidence. In practice, conductivity is most effective for trend analysis—not absolute purity quantification. For example, a sudden jump in conductivity often signals increased carryover, prompting investigation even if exact concentrations are uncertain.
Emerging Techniques
Advanced methods such as radioactive tracer analysis have been explored for steam purity monitoring, but are rarely used in standard applications due to cost, complexity, and regulatory concerns.
The Watertech Difference
Watertech's boiler water treatment programs integrate advanced chemistry, precise monitoring, and hands-on service to maintain optimal steam system performance. Our experts assist with:
- Sampling system design and installation
- Selection and calibration of purity testing methods
- On-site analysis and troubleshooting
- Customized treatment strategies to reduce carryover risks
By combining technical excellence with practical experience, we help facilities achieve cleaner steam, reduce downtime, and extend equipment life—delivering long-term value and peace of mind.
Let’s Evaluate Your System
Every facility is different, and steam purity challenges vary by application, design, and operational conditions. Watertech offers site evaluations to assess current conditions and recommend solutions tailored to your environment.
Request a site survey and discover how Watertech can help optimize your boiler system’s performance with reliable steam purity management.
