Level sensor

A fluid level sensor assembly comprising:

• a tubular housing arranged to be fitted into a fluid flow path of a system between a fluid line and an inlet to a valve, wherein the tubular housing defines an axial flow channel extending through the tubular housing from a first end to a second end, along an axis A, for fluid to flow from the fluid line of the system to the valve inlet;
• a sensor channel extending from the second end of the flow channel towards the first end substantially parallel to, and in fluid communication with the axial flow channel;
• a first sensor part located in the sensor channel such that the first sensor part can move axially within the sensor channel responsive to pressure of the fluid in the flow channel acting on the first sensor part in the sensor channel;
• a second sensor part provided on the tubular housing at an axial position between the second end and the first end selected such that when the fluid pressure is at a predetermined level, the first sensor part is at a position in the sensor channel adjacent the second sensor part such that the first and second sensor parts communicate with each other.