1) There is a leak in the gas pipeline or equipment;
2) The pressure difference between the upper and lower limits of the pressure switch is too small;
3) The air consumption is unstable;
4) The pressure maintenance valve spool is not tightly sealed and the spring is fatigued;
5) The air compressor pressure is set to a lower line.
(2) Elimination method.
1) Check the leak and eliminate it;
2) Reset (generally the upper and lower limit pressure difference is 0.2Mpa or more);
3) Increase the capacity of the gas tank;
4) Repair or replace the valve plug and replace the spring;
5) Reset the pressure switch.