diff --git a/applications/utilities/postProcessing/graphics/PV3FoamReader/PV3FoamReader/PV3FoamReader_SM.xml b/applications/utilities/postProcessing/graphics/PV3FoamReader/PV3FoamReader/PV3FoamReader_SM.xml
index 644b794a44..ef25ac0378 100644
--- a/applications/utilities/postProcessing/graphics/PV3FoamReader/PV3FoamReader/PV3FoamReader_SM.xml
+++ b/applications/utilities/postProcessing/graphics/PV3FoamReader/PV3FoamReader/PV3FoamReader_SM.xml
@@ -30,16 +30,16 @@
 
     <!-- Global settings -->
 
-    <!-- Extrapolate Walls check-box -->
+    <!-- Extrapolate Patches check-box -->
     <IntVectorProperty
-      name="ExtrapolateWalls"
-      command="SetExtrapolateWalls"
+      name="ExtrapolatePatches"
+      command="SetExtrapolatePatches"
       number_of_elements="1"
       default_values="0"
       animateable="0">
       <BooleanDomain name="bool"/>
       <Documentation>
-        Extrapolate internalField to wall and empty patches
+        Extrapolate internalField to non-constraint patches
       </Documentation>
     </IntVectorProperty>
 
diff --git a/applications/utilities/postProcessing/graphics/PV3FoamReader/PV3FoamReader/vtkPV3FoamReader.cxx b/applications/utilities/postProcessing/graphics/PV3FoamReader/PV3FoamReader/vtkPV3FoamReader.cxx
index 8fc518d745..c16a43deae 100644
--- a/applications/utilities/postProcessing/graphics/PV3FoamReader/PV3FoamReader/vtkPV3FoamReader.cxx
+++ b/applications/utilities/postProcessing/graphics/PV3FoamReader/PV3FoamReader/vtkPV3FoamReader.cxx
@@ -64,7 +64,7 @@ vtkPV3FoamReader::vtkPV3FoamReader()
 
     CacheMesh = 1;
 
-    ExtrapolateWalls = 0;
+    ExtrapolatePatches = 0;
     IncludeSets = 0;
     IncludeZones = 0;
     ShowPatchNames = 0;
diff --git a/applications/utilities/postProcessing/graphics/PV3FoamReader/PV3FoamReader/vtkPV3FoamReader.h b/applications/utilities/postProcessing/graphics/PV3FoamReader/PV3FoamReader/vtkPV3FoamReader.h
index fde87527de..bc21cd8ce8 100644
--- a/applications/utilities/postProcessing/graphics/PV3FoamReader/PV3FoamReader/vtkPV3FoamReader.h
+++ b/applications/utilities/postProcessing/graphics/PV3FoamReader/PV3FoamReader/vtkPV3FoamReader.h
@@ -65,9 +65,9 @@ public:
     vtkGetMacro(CacheMesh, int);
 
     // Description:
-    // FOAM extrapolate internal values onto the walls
-    vtkSetMacro(ExtrapolateWalls, int);
-    vtkGetMacro(ExtrapolateWalls, int);
+    // FOAM extrapolate internal values onto the patches
+    vtkSetMacro(ExtrapolatePatches, int);
+    vtkGetMacro(ExtrapolatePatches, int);
 
     // FOAM read sets control
     vtkSetMacro(IncludeSets, int);
@@ -183,7 +183,7 @@ private:
     int TimeStepRange[2];
     int CacheMesh;
 
-    int ExtrapolateWalls;
+    int ExtrapolatePatches;
     int IncludeSets;
     int IncludeZones;
     int ShowPatchNames;
diff --git a/applications/utilities/postProcessing/graphics/PV3FoamReader/vtkPV3Foam/vtkPV3Foam.C b/applications/utilities/postProcessing/graphics/PV3FoamReader/vtkPV3Foam/vtkPV3Foam.C
index 7a8fd89e9e..0ed3d53185 100644
--- a/applications/utilities/postProcessing/graphics/PV3FoamReader/vtkPV3Foam/vtkPV3Foam.C
+++ b/applications/utilities/postProcessing/graphics/PV3FoamReader/vtkPV3Foam/vtkPV3Foam.C
@@ -659,29 +659,55 @@ void Foam::vtkPV3Foam::addPatchNames(vtkRenderer* renderer)
         }
     }
 
+    // Count number of zones we're actually going to display. This is truncated
+    // to a max per patch
+
+    const label MAXPATCHZONES = 20;
+
+    label displayZoneI = 0;
+
+    forAll(pbMesh, patchI)
+    {
+        displayZoneI += min(MAXPATCHZONES, nZones[patchI]);
+    }
+
+
     zoneCentre.shrink();
 
     if (debug)
     {
         Info<< "patch zone centres = " << zoneCentre << nl
+            << "displayed zone centres = " << displayZoneI << nl
             << "zones per patch = " << nZones << endl;
     }
 
     // Set the size of the patch labels to max number of zones
-    patchTextActorsPtrs_.setSize(zoneCentre.size());
+    patchTextActorsPtrs_.setSize(displayZoneI);
 
     if (debug)
     {
         Info<< "constructing patch labels" << endl;
     }
 
+    // Actor index
+    displayZoneI = 0;
+
+    // Index in zone centres
     label globalZoneI = 0;
+
     forAll(pbMesh, patchI)
     {
         const polyPatch& pp = pbMesh[patchI];
 
         // Only selected patches will have a non-zero number of zones
-        for (label i=0; i<nZones[patchI]; i++)
+        label nDisplayZones = min(MAXPATCHZONES, nZones[patchI]);
+        label increment = 1;
+        if (nZones[patchI] >= MAXPATCHZONES)
+        {
+            increment = nZones[patchI]/MAXPATCHZONES;
+        }
+
+        for (label i = 0; i < nDisplayZones; i++)
         {
             if (debug)
             {
@@ -719,14 +745,15 @@ void Foam::vtkPV3Foam::addPatchNames(vtkRenderer* renderer)
 
             // Maintain a list of text labels added so that they can be
             // removed later
-            patchTextActorsPtrs_[globalZoneI] = txt;
+            patchTextActorsPtrs_[displayZoneI] = txt;
 
-            globalZoneI++;
+            globalZoneI += increment;
+            displayZoneI++;
         }
     }
 
     // Resize the patch names list to the actual number of patch names added
-    patchTextActorsPtrs_.setSize(globalZoneI);
+    patchTextActorsPtrs_.setSize(displayZoneI);
 
     if (debug)
     {
diff --git a/applications/utilities/postProcessing/graphics/PV3FoamReader/vtkPV3Foam/vtkPV3FoamVolFields.H b/applications/utilities/postProcessing/graphics/PV3FoamReader/vtkPV3Foam/vtkPV3FoamVolFields.H
index f217d1a889..6c8d32f470 100644
--- a/applications/utilities/postProcessing/graphics/PV3FoamReader/vtkPV3Foam/vtkPV3FoamVolFields.H
+++ b/applications/utilities/postProcessing/graphics/PV3FoamReader/vtkPV3Foam/vtkPV3FoamVolFields.H
@@ -132,8 +132,8 @@ void Foam::vtkPV3Foam::convertVolFields
                 isType<emptyFvPatchField<Type> >(ptf)
              ||
                 (
-                    typeid(patches[patchId]) == typeid(wallPolyPatch)
-                 && reader_->GetExtrapolateWalls()
+                    reader_->GetExtrapolatePatches()
+                && !polyPatch::constraintType(patches[patchId].type())
                 )
             )
             {