| 摘要 |
<p>This valve is constructed so that it opens automatically when the pressure in the passage controlled by the valve exceeds a first threshold value, and then remains open until the pressure drops below a second threshold value, with the second value being much lower than the first. The valve is particularly suitable for use as a vent valve in a motor vehicle fuel tank where the valve will remain closed (to prevent filling of the ullage space) whilst the tank is being filled, but can open and remain open to provide venting when the pressure builds up in the full tank. <IMAGE></p> |
