Field glossarypsidPounds per square inch differential, the pressure difference the gauge reads across a check or the reliefUsed across 2 Anvilfield field guides, most in Plumbing. Where this shows upPlumbingBackflow test procedure guidePlumbingBackflow failed test repair guide Related termsDC / DCVACross-connectionPVBRP / RPZSVB / SPVB Back to the full field glossary