TL;DR
A water hammer arrestor, the alternate spelling plumbers use interchangeably with arrester, is the piston- or bladder-type shock absorber fitted to supply piping where quick-closing valves keep slamming the water column to a halt. Beyond the noise, the repeated pressure spikes, which can exceed twice static pressure, fatigue solder joints, burst flex connectors, and shorten the life of valves and gauges.
What it means
A water hammer arrestor, the alternate spelling plumbers use interchangeably with arrester, is the piston- or bladder-type shock absorber fitted to supply piping where quick-closing valves keep slamming the water column to a halt. Beyond the noise, the repeated pressure spikes, which can exceed twice static pressure, fatigue solder joints, burst flex connectors, and shorten the life of valves and gauges. Plumbing codes require the devices where quick-closing valves exist, and placement matters: within a few feet of the valve generating the shock, accessible for eventual replacement since the internal seals do wear out.
Where it sits in the glossary
Water hammer arrestor is part of the Trade jargon group inside the ProFix Directory glossary. Browse every term in this category from the glossary index.
Why Ohio homeowners should know it
This is a term Ohio homeowners encounter when reading contractor quotes, hiring paperwork, or inspection reports. Understanding it well enough to ask one good follow-up question is usually all the protection a homeowner needs.
ProFix Directory keeps definitions short on the index page and saves the longer context — Ohio-specific rules, where the term comes from, and which ProFix tools touch it — for these per-term pages so the term is easy to cite and easy to share.
ProFix tools that touch this term
See also
License: CC-BY-4.0 — quote freely with attribution to ProFix Editorial Team / ProFix Directory.