Unit Function HDS Middle Range / HDS Premium RangePage 52 / 127 Service Manual 04.200843 5 12.23 Pressure and flow control valve with rotary controlThe pressure and flow control valve is designedas a rotary control between the handgun andspray lance.There are two ceramic discs (1, 2) inside thehigh-pressure duct.The ceramic disc (2) is rigidly connected to thehandgun connection (6). The ceramic disc (1) isconnected to the rotary control (5) and cantherefore be adjusted. The holes in the ceramicdiscs (1, 2) are staggered; this enables the flowrate and pressure to be varied when the discsare rotated.The diagram shows the two superimposedceramic discs (1, 2) and the water flow (blue) atvarious opening angles of 0° - 90°.At the minimum setting the water flows througha small hole in the middle of the ceramic discs(1, 2).1 Ceramic disc - spray lance side2 Ceramic disc - handgun side3 Handle, rotary control4 Connecting pin5 Housing, rotary control6 Handgun connection7 Spray lance connectionWater flow at opening angle 0° - 90°Cross-section through the rotary control (handgunside)Long-section through the rotary control62710° 10° 20° 30° 40°50° 60° 70° 80° 90°24325
