There are requirements for the overflow performance of the basin, and QB 2658-24 requires the basin for sanitary equipment to have an inflow of .7L/S, so it should not overflow the basin; The requirement of GB6952 for ceramic pots is that when water flows into the overflow hole for 5 minutes, there is no overflow of sanitary ware. Generally, the flow rate of washing faucet is not less than .2L/S, so the overflow speed can't keep up with the inlet speed of faucet, which is in line with the industry requirements.