How to set the discharge and cut-off pressure at the outlet of the gas regulator?

How to set the discharge and cut-off pressure at the outlet of the gas regulator?

There is a clear relationship and logical sequence between the outlet pressure, overpressure cut-off pressure, and release pressure of a gas regulator. Generally speaking, it is released first and then cut off. The following is a specific explanation:

(1) Pressure relationship: The outlet pressure is the pressure value output by the regulator during normal operation, which is set according to the demand of downstream gas equipment or pipeline network. The closing pressure is generally 1.15-1.25 times the outlet pressure. The release pressure should be higher than the closing pressure. It is usually considered to start releasing when it exceeds 10% -20% of the closing pressure, which means that the release pressure is generally about 1.3 times the outlet pressure. And the cut-off pressure is higher than the release pressure, usually exceeding 10% -20% of the release pressure to cut off the gas source, which is about 1.5 times or more the outlet pressure. So the relationship between the three is: cut-off pressure>release pressure>outlet pressure.  

(2) Action sequence: When the regulator malfunctions and causes an increase in outlet pressure, the first step is to reach the set relief pressure. At this point, the relief valve opens to release the gas in the pipeline into the atmosphere, reducing downstream pressure. If the pressure cannot be effectively reduced after the release action and continues to rise to reach the cut-off pressure setting value, the overpressure cut-off valve will act to cut off the gas source and prevent further pressure rise from causing danger. The design of releasing first and then cutting off is mainly to avoid unnecessary cutting off of the gas source in the event of temporary overpressure caused by non serious faults, which may affect normal gas supply. Due to the need for manual reset after cutting off, it will cause inconvenience to the gas supply, so priority should be given to relieving overpressure conditions through venting.