Deaerators remove dissolved oxygen and carbon dioxide from boiler feedwater, preventing corrosion throughout the steam cycle. Their internal components, trays, spray valves, and vent condensers, are subject to corrosion and erosion and require periodic replacement to maintain water quality performance.
AQ Process Systems sources and exports replacement trays, spray nozzles, vent condensers, level controls, and safety devices for both tray-type (cascade) and spray-type deaerators. We support units from all major manufacturers used in power plants, refineries, and industrial boiler houses.
Deaerator performance directly impacts boiler tube life, dissolved oxygen levels above 7 ppb accelerate internal corrosion. We ensure replacement parts meet the original design specifications for oxygen removal efficiency.
| Component | Specification | Description |
|---|---|---|
| Deaeration Internals | ||
| Tray Stacks (Cascade Type) | SS 304/316 | Stacked tray assemblies | Replacement tray stacks for tray-type deaerators, providing the surface area for steam-water contact and gas stripping. |
| Spray Nozzles / Valves | SS 316 | Various spray patterns | Atomising spray nozzles for spray-type deaerators, distributing feedwater into fine droplets for efficient deaeration. |
| Steam Distribution Pipes | SS | Perforated or slotted | Internal steam distribution headers and perforated pipes directing heating steam through the water curtain. |
| Vent Condensers | Shell & tube or coil type | SS tubes | Heat recovery condensers on the deaerator vent, recovering energy from the non-condensable gas vent stream. |
| Level & Pressure Control | ||
| Level Transmitters | DP, radar, or displacer | Storage tank level | Storage tank level transmitters controlling feedwater makeup and pump operation. |
| Level Control Valves | Globe type | Pneumatic or electric actuator | Feedwater makeup control valves maintaining correct storage tank level for uninterrupted boiler feed. |
| Pressure Regulators | Self-acting or pilot-operated | Steam supply | Steam pressure regulators controlling the deaerator operating pressure and temperature. |
| Safety Devices | ||
| Safety Valves | ASME VIII | Spring-loaded | Flanged | Overpressure protection for the deaerator vessel, set to MAWP, tested and certified. |
| Vacuum Breakers | Spring-loaded | Atmospheric protection | Vacuum breakers preventing vessel collapse during rapid cooldown or steam supply interruption. |
| Overflow Devices | Weir or float-operated | Atmospheric drain | Overflow protection preventing the deaerator storage tank from overfilling. |
| Storage Tank Components | ||
| Internal Baffles | CS or SS plate | Anti-surge | Internal baffles in the horizontal storage tank, preventing water surge and stabilising level control. |
| Manhole Gaskets | Spiral wound | CS/SS ring | Gaskets for storage tank inspection manholes, replaced during every internal inspection. |
| Nozzle Connections | Flanged | Feedwater outlet, makeup inlet, steam inlet | Replacement nozzles for corroded or damaged connections on the deaerator head and storage tank. |
Parts are matched to OEM material specifications and dimensional tolerances. Please provide the equipment manufacturer, model number, and serial number (if available) for precise part identification.
The most common deaerator spares are tray stacks (corrosion and erosion from oxygen-rich water), spray nozzles (plugging and erosion), vent condenser tubes (corrosion from non-condensable gases), safety valves (periodic recertification), vacuum breakers (spring fatigue), and level instruments (scaling and drift). Manhole gaskets are replaced during every inspection.
Tray life depends on water chemistry and oxygen loading. In well-maintained systems with good chemical treatment, SS 304 trays can last 10-15 years. In systems with poor water quality, high oxygen, or aggressive chemistry, replacement may be needed every 5-8 years. Inspect tray condition during annual boiler outages.
Yes. We supply replacement vent condensers, small shell & tube or coil-type heat exchangers mounted on the deaerator vent. These recover heat from the non-condensable gas vent stream, pre-heating incoming makeup water and reducing energy loss. We match the replacement to the original duty and mounting configuration.
If steam supply to the deaerator is interrupted suddenly, the steam inside condenses rapidly, creating a vacuum. The deaerator vessel (designed for internal pressure, not external) can collapse under atmospheric pressure. The vacuum breaker opens automatically when internal pressure drops below atmospheric, admitting air to prevent vessel implosion.
A properly functioning deaerator should reduce dissolved oxygen to below 7 ppb (parts per billion), the limit specified by ASME and most boiler manufacturers. If your deaerator is not meeting this target, the trays or spray nozzles may be damaged, the vent condenser may be plugged, or the steam supply pressure/temperature may be incorrect.
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