摘要 |
<p>A slam-shut valve or overpressure shutoff device used in series with, and upstream of, a pressure regulator to provide overpressure protection for apparatus downstream of the pressure regulator in the event of regulator failure. Overpressure or failure of the regulator automatically triggers operation of the slam-shut valve to close the same and prevent further passage of the gas through the pipeline. The slam-shut valve is normally in the open position, and the invention provides for manually resetting the slam-shut valve to reset it in the open position once it has been triggered closed.</p> |