Glossary
Expansion vessel
A pressure vessel with a flexible diaphragm that absorbs the expansion of heated water in sealed systems. Because water can sit largely undisturbed behind the diaphragm, an expansion vessel acts as a hidden dead leg and is a frequent risk-assessment failing unless it is the right type and properly maintained.
Covered in depth
Articles that use this term
- Using water system schematics and asset registers in risk assessments
- Design flaws: how poor system design can cause Legionella problems
- Failed remedial action close-out: why positive results keep returning
- Legionella risk assessment template: a worked UK example you can copy
- Water system asset register template for Legionella compliance
- Legionella compliance checklist: a downloadable audit checklist
- Water softeners and Legionella: why base-exchange units need assessing
- Break tanks and booster sets: the boosted-supply assets your tank guidance ignores
More terms
Cite this page
"Expansion vessel, Legionella glossary." Legionella.io. https://legionella.io/glossary/expansion-vessel/
Free to reuse under CC BY 4.0: quote, adapt or republish with attribution and a link back to the original.