... Main FrameNotice for Installation and Operation:Backblow inlet valve should adopt globe valve.Initial voltage of filtering should be below 0 ... backblow.Operation:Open inlet valve1, outlet valve 5, 6, 7 →close backblow valve 2, 3, 4, return valve 8→open inlet pump→ normal ... filter→ close inlet pump, inlet valve1 →open return valve8→close return valve ...