TL;DR
A low-pressure gas system is residential piping that operates at about 0.5 psi or less, delivering gas to appliances at the 7 to 11 inches of water column they are designed to burn. Because the pressure margin is thin, pipe must be generously sized using code tables for the total connected load and run length, unlike 2-psi systems that rely on downstream regulators.
What it means
A low-pressure gas system is residential piping that operates at about 0.5 psi or less, delivering gas to appliances at the 7 to 11 inches of water column they are designed to burn. Because the pressure margin is thin, pipe must be generously sized using code tables for the total connected load and run length, unlike 2-psi systems that rely on downstream regulators. Most existing homes are plumbed this way, which matters when adding a high-input load like a tankless water heater or generator.
Where it sits in the glossary
Low-pressure gas system 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.
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See also
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