I would like to ask everyone how to set the pressure interlock value for atmospheric-pressure reaction vessels

This setting indeed requires careful consideration, in order to ensure process safety while avoiding malfunctions that could affect production. Based on your parameters – with a nitrogen seal pressure of 1 KPa and an opening pressure for the one-way exhaust valve at 3 KPa – it is recommended that the high alarm threshold be set around 2 KPa, as this value lies between the nitrogen seal pressure and the valve’s opening pressure, allowing for early detection of an increasing pressure trend. The high alarm interlock value should be set between 2.5 KPa and 2.8 KPa, to leave some margin and prevent the interlock from being triggered when the valve operates normally, while still ensuring that pressure can be cut off or released in a timely manner before the valve fails. The final value should be determined by taking into account the equipment’s design pressure, the properties of the process medium, and relevant standards such as HG/T 20570; different industries may have varying regulations, so it is advisable to consult the equipment manufacturer or a safety engineer for confirmation

Core principle for setting the pressure interlock value in atmospheric-pressure reactors: It must be lower than the activation pressure of the safety relief devices (safety valves/blast disks), higher than the opening pressure of the normal vent valves, and allow for a margin for operation； Typical reference values are 10 kPa for alarm and 20 kPa (gauge pressure) for interlock; the specific values must be determined based on the equipment’s design pressure and the settings of the relief systems.