diff --git a/Modelica/Blocks/Sources.mo b/Modelica/Blocks/Sources.mo
index 8fbd5f270a..99b77f17d7 100644
--- a/Modelica/Blocks/Sources.mo
+++ b/Modelica/Blocks/Sources.mo
@@ -244,13 +244,13 @@ The Real output y is a step signal:
   block Ramp "Generate ramp signal"
     parameter Real height=1 "Height of ramp"
       annotation(Dialog(groupImage="modelica://Modelica/Resources/Images/Blocks/Sources/Ramp.png"));
-    parameter SI.Time duration(min=0.0, start=2)
-      "Duration of ramp (= 0.0 gives a Step)";
+    parameter SI.Time duration(min=Constants.small, start=2)
+      "Duration of ramp";
     extends Interfaces.SignalSource;
 
   equation
-    y = offset + (if time < startTime then 0 else if time < (startTime +
-      duration) then (time - startTime)*height/duration else height);
+    y = smooth(0, offset + (if time < startTime then 0 else if time < (startTime +
+      duration) then (time - startTime)*height/duration else height));
     annotation (
       Icon(coordinateSystem(
           preserveAspectRatio=true,
@@ -281,10 +281,6 @@ The Real output y is a ramp signal:
 <img src=\"modelica://Modelica/Resources/Images/Blocks/Sources/Ramp.png\"
      alt=\"Ramp.png\">
 </div>
-
-<p>
-If parameter duration is set to 0.0, the limiting case of a Step signal is achieved.
-</p>
 </html>"));
   end Ramp;
 
diff --git a/Modelica/Fluid/Examples/BranchingDynamicPipes.mo b/Modelica/Fluid/Examples/BranchingDynamicPipes.mo
index 106aeb4690..61fb08c110 100644
--- a/Modelica/Fluid/Examples/BranchingDynamicPipes.mo
+++ b/Modelica/Fluid/Examples/BranchingDynamicPipes.mo
@@ -81,17 +81,16 @@ replaceable package Medium=Modelica.Media.Air.MoistAir constrainedby
     p=100000) annotation (Placement(
         transformation(extent={{10,-10},{-10,10}}, rotation=90,
         origin={0,60})));
-  Modelica.Blocks.Sources.Ramp ramp1(
+  Modelica.Blocks.Sources.Step step1(
     offset=1e5,
     startTime=2,
-    height=1e5,
-    duration=0) annotation (Placement(transformation(extent={{-40,70},{-20,90}})));
+    height=1e5) annotation (Placement(transformation(extent={{-40,70},{-20,90}})));
   Modelica.Thermal.HeatTransfer.Sources.FixedHeatFlow[
                                               pipe2.nNodes] heat2(Q_flow=200*
         pipe2.dxs, alpha=-1e-2*ones(pipe2.n))
     annotation (Placement(transformation(extent={{-60,-20},{-40,0}})));
 equation
-  connect(ramp1.y, boundary4.p_in) annotation (Line(
+  connect(step1.y, boundary4.p_in) annotation (Line(
       points={{-19,80},{-8,80},{-8,72}},
       color={0,0,127},
       thickness=0.5));