The pressure above atmospheric within an exhaust system, caused by flow resistance. Typically, the lower the backpressure, the better the engine performance.

The flow resistance of downstream applications (so-called "backpressure"), which has an impact on the flow performance of flow regulators.

A backward surge of pressure from downstream to upstream of the filter. Can be the result of closing a valve or air entrapped in a liquid system.

The pressure above gravity at the head of the column. Expressed in psig, bar, atm., or MPa.