... PVC Swing Check Valve (Dual-Use in Vertical / Horizontal) Size: DN20-DN150 ( 3/4"- 6" ) ... psi PVC Swing Check Valve ( in Vertical or in Horizontal ) DIN, ANSI, JIS, BS Standard DN20-DN150 ... Can be Dual-Use in Vertical / HorizontalFull-Flow, Low Resistance. Small Opening Pressure ShiftNo Internal ... Opening CAUTION:Arrow Mark Indicates the Flow of FluidWhen in Horizontal Install, Make Sure the Arrow Mark ...