---
title: "Tube fouling"
description: "Tube fouling is the umbrella term for deposit accumulation on the gas-side outer surface of boiler and heat-exchanger tubes — economisers, superheaters, reheaters, air heaters, HRSG harps, recovery-boiler banks. The specific deposit composition varies by application, but the operational consequences are common."
canonical_url: "https://sylio.co/glossary/tube-fouling"
last_updated: "2026-06-28T02:29:32.363Z"
---

**Tube fouling** is the umbrella term for deposit accumulation on the gas-side outer surface of boiler and heat-exchanger tubes — [economisers](/glossary/economiser), [superheaters](/glossary/superheater), [reheaters](/glossary/reheater), [air heaters](/glossary/air-heater), [HRSG](/glossary/heat-recovery-steam-generator) harps, [recovery-boiler](/glossary/recovery-boiler) banks. The specific deposit composition varies by application, but the operational consequences are common.

## What tube fouling does

- **Insulates** the tube from the gas, reducing heat transfer
- **Raises** flue-gas-side pressure drop, derating the [ID fan](/glossary/id-fan)
- **Bonds chemically** with the tube surface, creating local corrosion sites
- **Channels** gas flow around blocked passages, leaving fouled tubes worse and unfouled tubes overworked

## Cleaning toolkit

[Sonic horns](/glossary/sonic-horn) prevent the early consolidation phase of tube fouling. Steam [sootblowers](/glossary/steam-sootblower) attack thicker deposits. Periodic offline water-washing or chemical cleaning addresses what neither can manage.

## Related terms

- [Fouling](/glossary/fouling)
- [Economiser](/glossary/economiser)
- [Superheater](/glossary/superheater)
- [Heat-transfer surface fouling](/glossary/heat-transfer-surface-fouling)
- [Sonic horn](/glossary/sonic-horn)