Definition
A device installed in a fluid or pneumatic line that restricts the maximum rate at which a fluid or gas can pass through it. In aircraft systems, a flow limiter protects downstream components and structure from excessive flow rates caused by a ruptured line, a failed seal, or a runaway actuator, by holding flow at or below a designed maximum even when upstream pressure is high.
Plain English
A built-in restriction in a line that caps how fast fluid or air can flow through it, so a leak or failure downstream cannot drain a system or damage parts at full speed.
Context Anchor
Seen in aircraft systems such as oxygen, hydraulic, or other pressurized lines where controlling the amount of flow is important.
Derivation
From 'flow' (the movement of fluid or gas) and 'limiter' (something that sets a maximum). The name describes its job directly: it limits flow.
Why Pilots Care
Prevents excessive fuel flow that could flood an engine or damage lines and pumps.
Analogy
It is like a narrow nozzle on a hose: water still comes out, but the narrow opening keeps the flow from becoming too large.
Intuition Check
A flow limiter does not necessarily stop flow. It limits how much flow can pass through at one time.
Example Sentence 1
The flow limiter in the landing gear hydraulic line prevented total fluid loss when the actuator seal failed.
Example Sentence 2
During the hydraulic inspection, the mechanic verified the flow limiter maintained pressure within limits.