Edema has many possible causes: 1  Prolonged standing or sitting, especially in hot weather, can cause excess fluid to accumulate in the feet, ankles and lower legs. 2  Tiny valves inside the veins of the legs can become weakened, causing a common problem called venous insufficiency.
Cars with nitrous-equipped engines can be identified by the purge of the delivery system that most drivers perform prior to reaching the starting line. A separate electrically operated valve is used to release air and gaseous nitrous oxide trapped in the delivery system.
A. The purge valve is an auxiliary nitrous solenoid that is activated manually by the driver prior to a nitrous assisted pass. This solenoid vents the gaseous nitrous from the supply line that connects the nitrous bottle to the nitrous solenoid. This allows a pure liquid nitrous charge to enter the engine for an instant surge of power. A purge valve is worth about a tenth of a second on a quarter mile pass. Yes, everyone needs a purge valve.