VALVE HAVING A MOVABLE SEAT AND A MOVABLE NEEDLE

摘要

A multi-function pressure relief valve (60) having a moveable seat (76) and a needle (100) is mounted on a fuel vapor separator (10). The needle (100) is connected to a float assembly (64) for opening and closing the pressure relief valve (60) for venting an internal chamber (38) of the fuel vapor separator (10). The moveable seat (76) is biased to engage the needle (100) for relieving excess pressure when vapor pressure in the internal chamber (38) exceeds a biasing force on the movable seat (76). The valve (60) opens in response to at least one of (1) changing fluid level in the fuel vapor separator (10), and (2) excess vapor pressure within the vapor fuel separator (10). During operation, the valve (60) vents an internal chamber (38) of the fuel vapor separator (10) by disengaging the needle (100) from the movable seat (76) using a float (64) attached to the needle (100). The valve (60) closes when the float (64) reaches a desired position to pressurize the internal chamber (38) by engaging the needle (100) to the movable seat (76). The valve (60) also releases excess vapor pressure in the internal chamber (38) when the pressure in the internal chamber (38) exceeds a biasing force on the movable seat (76) and disengages the movable seat (76) from the needle (100).