Valveless filters are widely used in surface water purification, circulating water bypass filtration, removal of suspended impurities from production wastewater, and filtration of organic wastewater after biochemical and secondary sedimentation treatment. Steel valve free filters mainly use the siphon principle for regular backwashing. The filter does not require valves for water inlet, outlet, flushing, and drainage, and operates automatically by hydraulic action.

Working Principle:
The raw water enters the filter tank through the water pipe and is filtered from top to bottom through the filter layer. It then enters the storage tank and is filled before being discharged into the clean water tank through the water outlet pipe. The continuous retention of suspended solids in the filter layer increases resistance, causing the water level in the siphon tube to continuously rise. When the water level reaches the mouth of the siphon auxiliary tube, water falls down from the tube and is carried away by the suction tube to remove the air descending from the siphon. When the vacuum degree reaches a certain value, siphon action occurs, causing water to backwash the filter material from bottom to top through the filter layer. When the water level of the flushing water tank drops to the siphon breaking pipe, air enters the siphon pipe, breaking the siphon effect. The backwash is completed and the filtration starts again.