diff --git a/PamhagenSysCtrl/Helpers/Pipeline/Graph.cs b/PamhagenSysCtrl/Helpers/Pipeline/Graph.cs
index 9a69ee2..ebd067a 100644
--- a/PamhagenSysCtrl/Helpers/Pipeline/Graph.cs
+++ b/PamhagenSysCtrl/Helpers/Pipeline/Graph.cs
@@ -10,10 +10,12 @@ namespace PamhagenSysCtrl.Helpers.Pipeline {
 
         }
 
-        public Pipe CreatePipe(INode start, INode end) {
+        public Pipe CreatePipe(INode start, INode end, bool verticalFirst = false) {
             Nodes.Add(start);
             Nodes.Add(end);
-            var p = new Pipe(start, end);
+            var p = new Pipe(start, end, verticalFirst);
+            start.Outputs.Add(p);
+            end.Inputs.Add(p);
             Edges.Add(p);
             return p;
         }
@@ -27,5 +29,13 @@ namespace PamhagenSysCtrl.Helpers.Pipeline {
             }
         }
 
+        public void Update(double x, double y) {
+            foreach (var e in Edges) {
+                e.Update(x, y);
+            }
+            foreach (var n in Nodes) {
+                n.Update(x, y);
+            }
+        }
     }
 }
diff --git a/PamhagenSysCtrl/Helpers/Pipeline/IEdge.cs b/PamhagenSysCtrl/Helpers/Pipeline/IEdge.cs
index 384632a..7267fc1 100644
--- a/PamhagenSysCtrl/Helpers/Pipeline/IEdge.cs
+++ b/PamhagenSysCtrl/Helpers/Pipeline/IEdge.cs
@@ -8,6 +8,7 @@ namespace PamhagenSysCtrl.Helpers.Pipeline {
         public bool Orientation { get; }
 
         public void Draw(Canvas canvas);
+        public bool Update(double x, double y);
 
     }
 }
diff --git a/PamhagenSysCtrl/Helpers/Pipeline/INode.cs b/PamhagenSysCtrl/Helpers/Pipeline/INode.cs
index d38b496..85dc744 100644
--- a/PamhagenSysCtrl/Helpers/Pipeline/INode.cs
+++ b/PamhagenSysCtrl/Helpers/Pipeline/INode.cs
@@ -6,8 +6,11 @@ namespace PamhagenSysCtrl.Helpers.Pipeline {
         public double CenterX { get; }
         public double CenterY { get; }
         public string Label { get; }
+        public ISet<IEdge> Inputs { get; }
+        public ISet<IEdge> Outputs { get; }
 
         public void Draw(Canvas canvas);
+        public bool Update(double x, double y);
 
     }
 }
diff --git a/PamhagenSysCtrl/Helpers/Pipeline/Pipe.cs b/PamhagenSysCtrl/Helpers/Pipeline/Pipe.cs
index a8b843b..c816347 100644
--- a/PamhagenSysCtrl/Helpers/Pipeline/Pipe.cs
+++ b/PamhagenSysCtrl/Helpers/Pipeline/Pipe.cs
@@ -56,5 +56,9 @@ namespace PamhagenSysCtrl.Helpers.Pipeline {
             canvas.Children.Add(a2);
             canvas.Children.Add(b2);
         }
+
+        public bool Update(double x, double y) {
+            return false;
+        }
     }
 }
diff --git a/PamhagenSysCtrl/Helpers/Pipeline/PipeJoin.cs b/PamhagenSysCtrl/Helpers/Pipeline/PipeJoin.cs
index 1ee674e..3d4b5e2 100644
--- a/PamhagenSysCtrl/Helpers/Pipeline/PipeJoin.cs
+++ b/PamhagenSysCtrl/Helpers/Pipeline/PipeJoin.cs
@@ -9,9 +9,15 @@ namespace PamhagenSysCtrl.Helpers.Pipeline {
         public double CenterY { get; set; }
         public string Label { get; } = "";
 
+        public ISet<IEdge> Inputs { get; init; }
+
+        public ISet<IEdge> Outputs { get; init; }
+
         public PipeJoin(double x, double y) {
             CenterX = x;
             CenterY = y;
+            Inputs = new HashSet<IEdge>();
+            Outputs = new HashSet<IEdge>();
         }
 
         public void Draw(Canvas canvas) {
@@ -24,5 +30,9 @@ namespace PamhagenSysCtrl.Helpers.Pipeline {
             e.SetValue(Canvas.TopProperty, CenterY - 9);
             canvas.Children.Add(e);
         }
+
+        public bool Update(double x, double y) {
+            return false;
+        }
     }
 }
diff --git a/PamhagenSysCtrl/Helpers/Pipeline/Pump.cs b/PamhagenSysCtrl/Helpers/Pipeline/Pump.cs
index 824fe84..b43a61a 100644
--- a/PamhagenSysCtrl/Helpers/Pipeline/Pump.cs
+++ b/PamhagenSysCtrl/Helpers/Pipeline/Pump.cs
@@ -7,14 +7,24 @@ namespace PamhagenSysCtrl.Helpers.Pipeline {
         public double CenterY { get; set; }
         public string Label { get; set; }
 
+        public ISet<IEdge> Inputs { get; init; }
+
+        public ISet<IEdge> Outputs { get; init; }
+
         public Pump(string label, double x, double y) {
             CenterX = x;
             CenterY = y;
             Label = label;
+            Inputs = new HashSet<IEdge>();
+            Outputs = new HashSet<IEdge>();
         }
 
         public void Draw(Canvas canvas) {
             
         }
+
+        public bool Update(double x, double y) {
+            return false;
+        }
     }
 }
diff --git a/PamhagenSysCtrl/Helpers/Pipeline/Tank.cs b/PamhagenSysCtrl/Helpers/Pipeline/Tank.cs
index 7cb1db4..a24fb2d 100644
--- a/PamhagenSysCtrl/Helpers/Pipeline/Tank.cs
+++ b/PamhagenSysCtrl/Helpers/Pipeline/Tank.cs
@@ -9,6 +9,9 @@ namespace PamhagenSysCtrl.Helpers.Pipeline {
         public bool IsFull => CallbackIsFull();
         public bool IsFilled => CallbackIsFilled();
 
+        public ISet<IEdge> Inputs { get; init; }
+        public ISet<IEdge> Outputs { get; init; }
+
         protected Func<bool> CallbackIsFilled;
         protected Func<bool> CallbackIsFull;
 
@@ -18,10 +21,16 @@ namespace PamhagenSysCtrl.Helpers.Pipeline {
             Label = label;
             CallbackIsFilled = cbFilled;
             CallbackIsFull = cbFull;
+            Inputs = new HashSet<IEdge>();
+            Outputs = new HashSet<IEdge>();
         }
 
         public void Draw(Canvas canvas) {
 
         }
+
+        public bool Update(double x, double y) {
+            return false;
+        }
     }
 }
diff --git a/PamhagenSysCtrl/Helpers/Pipeline/Trough.cs b/PamhagenSysCtrl/Helpers/Pipeline/Trough.cs
index e86d6c5..c6712ec 100644
--- a/PamhagenSysCtrl/Helpers/Pipeline/Trough.cs
+++ b/PamhagenSysCtrl/Helpers/Pipeline/Trough.cs
@@ -7,6 +7,8 @@ namespace PamhagenSysCtrl.Helpers.Pipeline {
         public double CenterY { get; set; }
         public string Label { get; set; }
         public bool IsFilled => CallbackIsFilled();
+        public ISet<IEdge> Inputs { get; init; }
+        public ISet<IEdge> Outputs { get; init; }
 
         protected Func<bool> CallbackIsFilled;
 
@@ -15,10 +17,16 @@ namespace PamhagenSysCtrl.Helpers.Pipeline {
             CenterY = y;
             Label = label;
             CallbackIsFilled = cbFilled;
+            Inputs = new HashSet<IEdge>();
+            Outputs = new HashSet<IEdge>();
         }
 
         public void Draw(Canvas canvas) {
             
         }
+
+        public bool Update(double x, double y) {
+            return false;
+        }
     }
 }
diff --git a/PamhagenSysCtrl/Helpers/Pipeline/Valve.cs b/PamhagenSysCtrl/Helpers/Pipeline/Valve.cs
index 21184db..481b86b 100644
--- a/PamhagenSysCtrl/Helpers/Pipeline/Valve.cs
+++ b/PamhagenSysCtrl/Helpers/Pipeline/Valve.cs
@@ -11,29 +11,41 @@ namespace PamhagenSysCtrl.Helpers.Pipeline {
 
         public bool IsOpen => CallbackIsOpen();
         public bool WantOpen => CallbackWantOpen();
+        public ISet<IEdge> Inputs { get; init; }
+        public ISet<IEdge> Outputs { get; init; }
 
         protected Func<bool> CallbackIsOpen;
         protected Func<bool> CallbackWantOpen;
 
+        private Ellipse Me;
+
         public Valve(string label, double x, double y, Func<bool> cbOpen, Func<bool> cbWant) {
             CenterX = x;
             CenterY = y;
             Label = label;
             CallbackIsOpen = cbOpen;
             CallbackWantOpen = cbWant;
+            Inputs = new HashSet<IEdge>();
+            Outputs = new HashSet<IEdge>();
         }
 
         public void Draw(Canvas canvas) {
-            var e = new Ellipse() {
+            Me = new Ellipse() {
                 Height = 20,
                 Width = 20,
                 Fill = Brushes.Gray,
                 Stroke = Brushes.Black,
                 StrokeThickness = 2,
             };
-            e.SetValue(Canvas.LeftProperty, CenterX - 10);
-            e.SetValue(Canvas.TopProperty, CenterY - 10);
-            canvas.Children.Add(e);
+            Me.SetValue(Canvas.LeftProperty, CenterX - 10);
+            Me.SetValue(Canvas.TopProperty, CenterY - 10);
+            canvas.Children.Add(Me);
+        }
+
+        public bool Update(double x, double y) {
+            var hover = Math.Sqrt(Math.Pow(CenterX - x, 2) + Math.Pow(CenterY - y, 2)) <= 10;
+            Me.Fill = hover ? Brushes.LightGray : Brushes.Gray;
+            return hover;
         }
     }
 }
diff --git a/PamhagenSysCtrl/Windows/MainWindow.xaml.cs b/PamhagenSysCtrl/Windows/MainWindow.xaml.cs
index e93380d..3f9075c 100644
--- a/PamhagenSysCtrl/Windows/MainWindow.xaml.cs
+++ b/PamhagenSysCtrl/Windows/MainWindow.xaml.cs
@@ -39,6 +39,9 @@ namespace PamhagenSysCtrl {
                 };
                 ValvePanel.Children.Add(b);
             }
+
+            var w = new PlantSchemeWindow();
+            w.Show();
         }
 
         public async void ConnectButton_Click(object? sender, RoutedEventArgs evt) {
@@ -54,8 +57,6 @@ namespace PamhagenSysCtrl {
                 MessageBox.Show(str, "SPS-Fehler", MessageBoxButton.OK, MessageBoxImage.Error);
                 return;
             }
-            var w = new PlantSchemeWindow();
-            w.Show();
         }
 
         public void OnUpdate(object? sender, PlantEventArgs evt) {
diff --git a/PamhagenSysCtrl/Windows/PlantSchemeWindow.xaml b/PamhagenSysCtrl/Windows/PlantSchemeWindow.xaml
index 57bb41c..192a445 100644
--- a/PamhagenSysCtrl/Windows/PlantSchemeWindow.xaml
+++ b/PamhagenSysCtrl/Windows/PlantSchemeWindow.xaml
@@ -5,7 +5,7 @@
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:local="clr-namespace:PamhagenSysCtrl.Windows"
         Title="Schema - Anlagensteuerung Pamhagen" Height="450" Width="800">
-    <Grid>
+    <Grid MouseMove="SchemeCanvas_MouseMove">
         <Canvas x:Name="SchemeCanvas">
         </Canvas>
     </Grid>
diff --git a/PamhagenSysCtrl/Windows/PlantSchemeWindow.xaml.cs b/PamhagenSysCtrl/Windows/PlantSchemeWindow.xaml.cs
index 4e8086c..3937a0c 100644
--- a/PamhagenSysCtrl/Windows/PlantSchemeWindow.xaml.cs
+++ b/PamhagenSysCtrl/Windows/PlantSchemeWindow.xaml.cs
@@ -3,41 +3,77 @@ using PamhagenSysCtrl.Helpers.Pipeline;
 using System.Drawing;
 using System.Security.Cryptography.X509Certificates;
 using System.Windows;
+using System.Windows.Input;
 using System.Windows.Media;
 using System.Windows.Shapes;
 
 namespace PamhagenSysCtrl.Windows {
     public partial class PlantSchemeWindow : Window {
-        
+
+        private readonly Graph Graph;
+
         public PlantSchemeWindow() {
             InitializeComponent();
             App.Plant?.Update += OnUpdate;
 
-            var graph = new Graph();
+            Graph = new Graph();
 
             var mw1 = new Trough("MW1", 200, 50, () => App.Plant?.FillLevelA1 != FillState.Empty);
             var mw2 = new Trough("MW2",  50, 50, () => App.Plant?.FillLevelA1 != FillState.Empty);
             var mp1 = new Pump("MP1", 200, 80);
             var mp2 = new Pump("MP2",  50, 80);
-
             var x1 = new PipeJoin(200, 100);
             var x2 = new PipeJoin(50, 100);
 
-            var v1 = new Valve("V1", 200, 150, () => App.Plant?.IsValveOpen(1) ?? false, () => App.Plant?.WantValveOpen(1) ?? false);
-            var v2 = new Valve("V2",  50, 150, () => App.Plant?.IsValveOpen(2) ?? false, () => App.Plant?.WantValveOpen(2) ?? false);
-            var v3 = new Valve("V3",  80, 150, () => App.Plant?.IsValveOpen(3) ?? false, () => App.Plant?.WantValveOpen(3) ?? false);
-            var v4 = new Valve("V4", 170, 150, () => App.Plant?.IsValveOpen(4) ?? false, () => App.Plant?.WantValveOpen(4) ?? false);
+            Graph.CreatePipe(mw1, mp1);
+            Graph.CreatePipe(mw2, mp2);
+            Graph.CreatePipe(mp1, x1);
+            Graph.CreatePipe(mp2, x2);
 
-            graph.CreatePipe(mw1, mp1);
-            graph.CreatePipe(mw2, mp2);
-            graph.CreatePipe(mp1, x1);
-            graph.CreatePipe(mp2, x2);
-            graph.CreatePipe(x1, v1);
-            graph.CreatePipe(x1, v4);
-            graph.CreatePipe(x2, v2);
-            graph.CreatePipe(x2, v3);
+            var v1 = CreateValve(1, 200, 150);
+            var v2 = CreateValve(2,  50, 150);
+            var v3 = CreateValve(3,  80, 150);
+            var v4 = CreateValve(4, 170, 150);
 
-            graph.Draw(SchemeCanvas);
+            Graph.CreatePipe(x1, v1);
+            Graph.CreatePipe(x1, v4);
+            Graph.CreatePipe(x2, v2);
+            Graph.CreatePipe(x2, v3);
+
+            var x3 = new PipeJoin(200, 180);
+            var x4 = new PipeJoin(200, 210);
+            var x5 = new PipeJoin(50, 210);
+            var x6 = new PipeJoin(50, 240);
+
+            Graph.CreatePipe(v1, x3, true);
+            Graph.CreatePipe(v3, x3, true);
+            Graph.CreatePipe(x3, x4, true);
+            Graph.CreatePipe(v2, x5, true);
+            Graph.CreatePipe(v4, x5, true);
+            Graph.CreatePipe(x5, x6, true);
+
+            var v5 = CreateValve(5, 250, 210);
+            var v6 = CreateValve(6, 200, 280);
+            var v7 = CreateValve(7, 125, 240);
+            var v8 = CreateValve(8,  50, 280);
+            var v9 = CreateValve(9, 300, 240);
+
+            Graph.CreatePipe(x4, v5);
+            Graph.CreatePipe(x4, v6);
+            Graph.CreatePipe(x6, v7);
+            Graph.CreatePipe(x6, v8);
+            Graph.CreatePipe(v7, v9);
+
+            Graph.Draw(SchemeCanvas);
+        }
+
+        private static Valve CreateValve(int n, double x, double y) {
+            return new($"V{n}", x, y, () => App.Plant?.IsValveOpen(4) ?? false, () => App.Plant?.WantValveOpen(4) ?? false);
+        }
+
+        private void SchemeCanvas_MouseMove(object sender, MouseEventArgs evt) {
+            var p = evt.GetPosition(SchemeCanvas);
+            Graph.Update(p.X, p.Y);
         }
 
         public void OnUpdate(object? sender, PlantEventArgs evt) {