Index: Demo/Ringtoets/test/Demo.Ringtoets.Test/Commands/AddNewDemoAssessmentSectionCommandTest.cs
===================================================================
diff -u -r9ffe6315bcf05d461cb320ff137d4d3c6a552ba0 -ra02e352e63811b18cd5455768a1beb2b9a320e9f
--- Demo/Ringtoets/test/Demo.Ringtoets.Test/Commands/AddNewDemoAssessmentSectionCommandTest.cs	(.../AddNewDemoAssessmentSectionCommandTest.cs)	(revision 9ffe6315bcf05d461cb320ff137d4d3c6a552ba0)
+++ Demo/Ringtoets/test/Demo.Ringtoets.Test/Commands/AddNewDemoAssessmentSectionCommandTest.cs	(.../AddNewDemoAssessmentSectionCommandTest.cs)	(revision a02e352e63811b18cd5455768a1beb2b9a320e9f)
@@ -401,7 +401,7 @@
 
             Assert.AreEqual(9.81, inputParameters.WaterVolumetricWeight, 1e-3);
             Assert.AreEqual(0.3, inputParameters.SellmeijerReductionFactor, 1e-3);
-            Assert.AreEqual(16.2, inputParameters.SandParticlesVolumicWeight, 1e-3);
+            Assert.AreEqual(16.19, inputParameters.SandParticlesVolumicWeight, 1e-3);
             Assert.AreEqual(0.25, inputParameters.WhitesDragCoefficient, 1e-3);
             Assert.AreEqual(1.33e-6, inputParameters.WaterKinematicViscosity, 1e-3);
             Assert.AreEqual(9.81, inputParameters.Gravity, 1e-3);
@@ -449,7 +449,7 @@
             Assert.AreEqual(1.784, calculation.Output.UpliftFactorOfSafety, 1e-3);
             Assert.AreEqual(2.019, calculation.Output.UpliftZValue, 1e-3);
             Assert.AreEqual(0.955, calculation.Output.SellmeijerFactorOfSafety, 1e-3);
-            Assert.AreEqual(-0.053, calculation.Output.SellmeijerZValue, 1e-3);
+            Assert.AreEqual(-0.054, calculation.Output.SellmeijerZValue, 1e-3);
         }
 
         private static void AssertCalculationInFailureMechanismSectionResult(PipingCalculationScenario calculation, PipingFailureMechanismSectionResult[] sectionResults, IEnumerable<PipingCalculationScenario> calculations)
Index: Ringtoets/Piping/src/Ringtoets.Piping.Data/GeneralPipingInput.cs
===================================================================
diff -u -r7d8579f17abe04611f9edd55afecb6b85605a04d -ra02e352e63811b18cd5455768a1beb2b9a320e9f
--- Ringtoets/Piping/src/Ringtoets.Piping.Data/GeneralPipingInput.cs	(.../GeneralPipingInput.cs)	(revision 7d8579f17abe04611f9edd55afecb6b85605a04d)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Data/GeneralPipingInput.cs	(.../GeneralPipingInput.cs)	(revision a02e352e63811b18cd5455768a1beb2b9a320e9f)
@@ -41,7 +41,6 @@
             SellmeijerModelFactor = 1.0;
             WaterVolumetricWeight = 9.81;
             CriticalHeaveGradient = 0.3;
-            SandParticlesVolumicWeight = 16.2;
             WhitesDragCoefficient = 0.25;
             BeddingAngle = 37;
             WaterKinematicViscosity = 1.33e-6;
@@ -106,7 +105,13 @@
         /// under water.
         /// [kN/m³]
         /// </summary>
-        public double SandParticlesVolumicWeight { get; private set; }
+        public double SandParticlesVolumicWeight 
+        {
+            get
+            {
+                return 26.0 - waterVolumetricWeight;
+            }
+        }
 
         /// <summary>
         /// Gets the White's drag coefficient.
Index: Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/GeneralPipingInputTest.cs
===================================================================
diff -u -r7d8579f17abe04611f9edd55afecb6b85605a04d -ra02e352e63811b18cd5455768a1beb2b9a320e9f
--- Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/GeneralPipingInputTest.cs	(.../GeneralPipingInputTest.cs)	(revision 7d8579f17abe04611f9edd55afecb6b85605a04d)
+++ Ringtoets/Piping/test/Ringtoets.Piping.Data.Test/GeneralPipingInputTest.cs	(.../GeneralPipingInputTest.cs)	(revision a02e352e63811b18cd5455768a1beb2b9a320e9f)
@@ -42,7 +42,7 @@
 
             Assert.AreEqual(0.3, inputParameters.CriticalHeaveGradient);
 
-            Assert.AreEqual(16.2, inputParameters.SandParticlesVolumicWeight);
+            Assert.AreEqual(16.19, inputParameters.SandParticlesVolumicWeight, 1e-6);
             Assert.AreEqual(0.25, inputParameters.WhitesDragCoefficient);
             Assert.AreEqual(37, inputParameters.BeddingAngle);
             Assert.AreEqual(1.33e-6, inputParameters.WaterKinematicViscosity);
@@ -67,7 +67,7 @@
         }
 
         [Test]
-        public void WaterVolumetricWeight_SetValidValue_ValueSet()
+        public void WaterVolumetricWeight_SetValidValue_ValueSetAndSandParticlesVolumicWeightUpdated()
         {
             // Setup
             const double newValue = 5.69;
@@ -78,6 +78,7 @@
 
             // Assert
             Assert.AreEqual(newValue, inputParameters.WaterVolumetricWeight);
+            Assert.AreEqual(26.0 - newValue, inputParameters.SandParticlesVolumicWeight);
         }
     }
 }
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