TERM-DIFFERENTIAL-PRESSURE
Differential Pressure
Filtration Performance
Also: pressure drop · pressure differential · ΔP
Abbrev: ΔP · dP
Canonical Definition
The pressure difference (ΔP) measured across a filter element between the upstream (dirty) and downstream (clean) sides, typically expressed in bar, millibar (mbar), or pounds per square inch (psi). A clean filter element has low differential pressure at rated flow. As the element loads with contaminant, differential pressure increases progressively until reaching the element's service limit, triggering replacement. In air intake systems, differential pressure is termed restriction.
Engineering Context
Differential pressure monitoring is the primary method for determining filter service life in hydraulic and lubrication systems. Bypass valves are set to open at a maximum differential pressure (typically 3–6 bar for hydraulic elements, 1.5–4 bar for lube filters) to protect the downstream circuit from flow starvation when the element is fully loaded. Continuous ΔP sensors enable condition-based replacement in high-criticality systems.
Related Technologies
Protection Systems
Knowledge Center Articles
KC-00 Governance Metadata
| Permanent ID | TERM-DIFFERENTIAL-PRESSURE |
| Category | Filtration Performance |
| Status | Published |
| Version | 1.0 |
| Last Reviewed | 2026-07-05 |