Success Stories / Boilers
Unit Optimization Service · Boilers
A boiler condensate/makeup water level loop spent four weeks running at just 8.6% Overall Controller Effectiveness. A single tuning fix pushed it to 91.6% overnight, a +83-point jump that translated to ~$47,500 a year in gas savings and valve-wear avoidance.
$47,500/yr
Estimated annual value
The challenge
Boilers continuously lose water as steam leaves the system. Condensate return recovers only a portion of the lost moisture, so a secondary water supply is needed to make up the difference. A level controller on the condensate/makeup system is often used to modulate a valve which holds the tank's level at its designated Setpoint. Run the level too low and the boiler risks a low-water trip, but run it too high and the same tank can overflow or carry water into the steam system.
Low-water trips are unplanned shutdowns that carry real costs. So too, overflows into the steam system can damage downstream equipment and steam quality. In this case, keeping the level clear of both extremes forced the valve into wide, wasteful swings and an average OCE of 8.6%. Retuning the loop cut makeup-water flow by 29.3%, worth a documented ~$47,500 a year in avoided gas cost and valve wear. Keeping the loop clear of both failure modes provided additional benefits.
The results
Gas use
Retuning cut time-weighted makeup flow by 29.3%. Less cold water to heat by 140°F means about $45,500 a year in avoided gas consumption.
Valve wear
Wide sawtooth CO swings were settled into a tight band, reducing valve travel and cutting $2,000 a year in wear.
Level tracking
A +83-point OCE jump came almost entirely from an increase to % Good Error, so the gain was realized by improved tracking accuracy.
Trip & overflow risk
A loop holding Setpoint keeps the tank clear of both a low-water trip and overflow or carryover into the steam system.
Schematic is a simplified representation of the boiler condensate/makeup system and loop LIC2101. Before/after window Jul 1–26 vs. Jul 27–Aug 31, 2025. Annual value uses stated assumptions: 50 GPM valve, 140°F rise, 80% efficiency, $4.50/MMBtu gas.
Overall Controller Effectiveness · A Universal Performance Measure
The connection between PID performance and boiler economics is not theoretical. It's calculable, loop by loop. PlantESPâ„¢ is the leading control loop performance monitoring (CLPM) solution. PlantESP actively monitors PID performance on a plant-wide basis and it has been successfully deployed across all variety of unit operations involving heat transfer.
Among its metrics, PlantESP scores every loop using Overall Controller Effectiveness (OCE). Like OEE, OCE is a composite KPI that assesses three operating attributes (Availability, Performance, Quality) and facilitates the benchmarking of individual PID loops, unit operations, and entire facilities.
≥ 95%
Availability
Time in Normal (auto/cascade)
≥ 90%
Performance
Time Not Saturated (off limits)
≥ 85%
Quality
% Good Error within tolerance
Overall Controller Effectiveness =
Time in Normal × Time Not Saturated × % Good Error
A loop meeting all three thresholds scores 72.7%, the threshold for world-class control. Because the terms multiply, a loop running only 80/80/80 falls to 51.2%. OCE highlights weakness in any one dimension, which is why it gauges control quality and financial exposure alike. Try the OCE calculator
Framing poor performance as lost profit
8.6% → 91.6%
Average OCE before vs. after improvements
$45,500/yr
Gas savings from 29.3% lower makeup flow
$2,000/yr
Avoided wear and tear on the final control element
A project-based, control-strategy-improvement offering purpose-built for interactive, multi-loop unit operations like a boiler makeup water system. Engage to find and fix the losses, then sustain the gains. Explore the service →
Engage · 01–04
01 Kick-off
Prioritize by Strategy
Rank loops, units, and areas against the plant's own goals: level, energy, reliability.
02 Monthly
Identify Bad Actors
Control Station engineers pinpoint that scope's top 10 bad-actor loops every month.
03 Monthly
Tune the Loops
Four hours per month of direct, hands-on tuning support to resolve those loops.
04 As needed
Strategy Change
When tuning cannot close the gap, escalate to a more strategic assessment and action plan.
Sustain · Ongoing
Quarterly
Assess the Value
Financial impact of the 10–20% typical Percent Good Error (PGE) gain from resolved bad-actor tuning.
Monthly
Track OCE Live
Unit Operation Performance Indicators in PlantESP keep the OCE trend visible.
Quarterly
Report to Stakeholders
Benchmark against industry peers for sponsors and non-technical stakeholders.
Annual
Plan the Roadmap
Update a one-to-three year plan for closing whatever performance gap remains.
Keep reading
Decades of domain expertise
Control Station is the process industry's leading provider of controller performance monitoring and analytics. PlantESPâ„¢ supports hundreds of facilities worldwide, backed by an engineering team focused solely on process control.
Contact us for a no-obligation loop performance assessment and a site-specific estimate of the opportunity hidden in your regulatory controls.
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