In order to study the effect of disc defects on the performance of the regulator,computational fluid dynamics was used to study the performance of the regulator in normal and disc gap fault states,and the internal flow field changes of the two regulator model states were analyzed.Then they were compared with the field experimental results.The simulation results show that the numerical simulation results of the model better reflect the operating conditions of the internal flow field of the regulator.When a small gap appeared on the valve flap of the pressure regulator,with a small opening of the valve port,the gas flow rate at the valve port has a large disturbance speed,which will cause a large fluctuation in the flow rate at the valve port.An experiment platform was set up,a 300 mm pipe section and a flow meter were installed outside the valve body connection,and the simulation results were compared with the pressure data detected on the spot.Under normal conditions,the simulation results are consistent with the experimental results.There is no disturbance in the flowmeter data outside the 128 mm pipe section.It is concluded that the valve body is connected to at least a 130 mm pipe section,which can avoid the impact of small damage to the flow rate monitoring.