TL;DR
A main drain test is the annual flow test on a fire sprinkler system in which the inspector opens the system's primary drain valve and watches the pressure gauges to confirm the water supply has not degraded. A pressure drop noticeably larger than previous years signals a closing valve, obstruction, or municipal supply problem upstream.
What it means
A main drain test is the annual flow test on a fire sprinkler system in which the inspector opens the system's primary drain valve and watches the pressure gauges to confirm the water supply has not degraded. A pressure drop noticeably larger than previous years signals a closing valve, obstruction, or municipal supply problem upstream. NFPA 25 requires it yearly and after any supply-side work, with results logged on the inspection report.
Where it sits in the glossary
Main drain test 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
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