Corrosion Risk Was Building Inside a Critical Steam System

Background

Oxygen Breakthrough Was Eroding Boiler Reliability

A corrosion problem inside a hospital steam system with real operational consequences

The Facility

The facility operated low-pressure steam boilers serving a regional hospital. Those boilers supported heat, sterilization processes, and domestic hot water. In a healthcare environment, that makes the steam system critical infrastructure rather than background equipment.

System Baseline Boiler feedwater passed through mechanical deaeration equipment intended to remove dissolved oxygen before the water entered the boilers. Over time, that upstream protection became inconsistent.

The Problem

As the deaerator aged, dissolved oxygen readings in the feedwater began to fluctuate. That oxygen was then carried into a hot steel system where it accelerated internal corrosion. Operators began seeing the effect in boiler tubes and condensate return lines.

The risk was not theoretical. Pitting, leaks, and repeated maintenance exposure were building inside a system the hospital needed to trust. Replacing the deaerator was possible, but it meant capital spend. The immediate need was a practical way to stop oxygen from continuing to damage the boilers.

Situation Overview

The Operating Pressure

Aging Deaeration Equipment Mechanical oxygen removal was no longer performing consistently.

Oxygen Reaching the Boiler Dissolved oxygen was entering the system and attacking internal metal surfaces.

Maintenance Risk Increasing Tube leaks, unplanned service calls, and shutdown pressure were rising.

Challenge

The Problem Was Mechanical Upstream and Chemical at the Point of Failure

The system needed dependable oxygen control, not just hope that the deaerator held

Status Quo: Rely on Deaeration Alone

Oxygen excursions continue when deaerator performance drifts
Pitting corrosion remains active inside boiler tubes
Condensate return damage continues to accumulate
Maintenance becomes increasingly reactive
Shutdown risk remains elevated
Tube life shortens under repeated oxygen attack
Capital replacement pressure grows over time

Alternative: Chemical Oxygen Scavenging

Neutralizes oxygen that escapes upstream removal
Reduces pitting risk at the point of corrosion
Stabilizes boiler protection under variable conditions
Lowers maintenance burden and leak frequency
Supports longer service life for internal metal surfaces
Provides a practical secondary barrier
Improves reliability without immediate capital replacement

Root Cause Analysis Dissolved oxygen is one of the most aggressive corrosion drivers in a steam system. Once it reaches hot steel, it promotes localized pitting rather than mild uniform wear. That matters because tube failure usually comes from concentrated attack, not even thinning. In this case, the hospital’s deaeration equipment was no longer removing oxygen consistently enough to prevent that damage pattern.

Solution

A Continuous Oxygen Scavenging Program with CI OS100

Chemical control applied directly where the risk became real

Chem International recommended a downstream oxygen control program built around continuous chemical scavenging. The objective was simple: consume dissolved oxygen before it had time to attack boiler metal.

Product Used: CI OS100 Oxygen Scavenger

CI OS100 A concentrated, catalyzed sodium sulfite oxygen scavenger formulated for low- and medium-pressure steam boilers. CI OS100 reacts rapidly with dissolved oxygen and converts it into a stable, non-corrosive byproduct, helping reduce pitting risk and protect boiler internals.

Application Protocol

Continuous injection into the boiler feedwater line
Target residual maintained in the 50–100 ppm range
Routine operator testing to confirm active protection
Dosage adjustment based on feedwater demand and system conditions

                    Strategic Advantage
                    This approach did not depend on perfect mechanical deaeration. It provided a second line of defense. Instead of assuming the deaerator removed all oxygen, the hospital gained a direct control point where remaining oxygen could be neutralized reliably before it caused damage.
                  

Implementation

Implementation and Monitoring

Baseline review, continuous feed, and disciplined residual control

Baseline Review

Feedwater oxygen conditions and operating trends were reviewed to confirm the oxygen breakthrough pattern and establish a treatment starting point based on actual system behavior.

Continuous Feed Setup

CI OS100 was introduced through continuous injection into the boiler feedwater line. The dosage was calibrated to system demand so residual scavenger protection remained present under normal operating conditions.

Residual Verification

Operators began routine testing to confirm the scavenger residual remained within the target range. This turned the treatment from a product feed into an actual control program.

Stabilization Phase

With oxygen control in place, feedwater conditions became more stable, corrosion indicators leveled out, and the system moved away from repeated reactive maintenance events.

Results

Operational Improvement and Stronger Internal Protection

Reduced oxygen risk, fewer incidents, and better boiler reliability

Oxygen Control Restored Dissolved oxygen was brought down to a consistently controlled condition, removing the main trigger for internal pitting.

Corrosion Indicators Stabilized Boiler-side conditions trended more consistently, supporting the conclusion that active oxygen attack had been materially reduced.

Fewer Unplanned Maintenance Events Leak exposure and shutdown pressure declined, reducing the burden on maintenance staff and improving system confidence.

Longer Equipment Life Outlook With oxygen-driven pitting brought under control, the hospital improved its expected service life for boiler tubes and related internals.

Performance Snapshot

Program Outcome

Dissolved Oxygen Reduced to controlled low-level condition

Corrosion Activity Stabilized versus prior fluctuating conditions

Maintenance Burden Reduced from repeated reactive events

Operational Confidence Improved in a critical hospital steam system

Financial Impact

Prevention Cost Less Than Failure

A modest treatment program protecting against repair, shutdown, and premature equipment loss

Economic Logic

Low

Ongoing chemical cost

Low

Routine testing burden

High

Avoided repair exposure

High

Protected asset value

Program Value

Failure Deferred

The oxygen scavenging program reduced exposure to tube leaks, emergency response, and accelerated internal deterioration in a system where downtime affected more than maintenance budgets.

The economic case was straightforward: a controlled chemical program cost less than repeated repair events, tube failure, and the operational disruption tied to steam outages.

The operational value was even stronger: in a hospital, boiler reliability supports heat, sterilization, and hot water continuity. Preventing corrosion was also protecting service continuity.

                    Secondary Value
                    The facility gained better visibility into system condition, better operator control, and a more defensible maintenance position. Instead of waiting for the next oxygen-driven failure, staff had a program in place to reduce the risk before it escalated.
                  

Operator Takeaways

Key Lessons for Boiler Operators

Oxygen Is a Serious Internal Threat

Dissolved oxygen does not need much time to initiate pitting inside a steam boiler.

Mechanical Removal Is Not Always Enough

Aging deaeration equipment can drift. Chemical backup closes that protection gap.

Residual Control Matters

Without testing and confirmation, oxygen scavenging is not a control program.

Fast Chemistry Has Real Value

Catalyzed scavengers reduce the time oxygen has to attack hot steel surfaces.

Reactive Maintenance Is Expensive

Tube leaks and emergency shutdowns cost more than disciplined prevention.

Reliability Has Facility-Wide Impact

In healthcare, protecting the boiler helps protect the operation around it.