diff --git a/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoam.C b/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoam.C
index 69be02156a..bade666a7a 100644
--- a/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoam.C
+++ b/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoam.C
@@ -47,6 +47,20 @@ License
 namespace Foam
 {
     defineTypeNameAndDebug(vtkPVFoam, 0);
+
+    // file-scope
+    static word updateStateName(polyMesh::readUpdateState state)
+    {
+        switch (state)
+        {
+            case polyMesh::UNCHANGED:      return "UNCHANGED";
+            case polyMesh::POINTS_MOVED:   return "POINTS_MOVED";
+            case polyMesh::TOPO_CHANGE:    return "TOPO_CHANGE";
+            case polyMesh::TOPO_PATCH_CHANGE: return "TOPO_PATCH_CHANGE";
+        };
+
+        return "UNKNOWN";
+    }
 }
 
 
@@ -138,27 +152,15 @@ int Foam::vtkPVFoam::setTime(int nRequest, const double requestTimes[])
             << ", nearestIndex = " << nearestIndex << endl;
     }
 
-
-    // see what has changed
+    // See what has changed
     if (timeIndex_ != nearestIndex)
     {
         timeIndex_ = nearestIndex;
         runTime.setTime(Times[nearestIndex], nearestIndex);
 
-        // the fields change each time
+        // When the changes, so do the fields
         fieldsChanged_ = true;
-
-        if (meshPtr_)
-        {
-            if (meshPtr_->readUpdate() != polyMesh::UNCHANGED)
-            {
-                meshChanged_ = true;
-            }
-        }
-        else
-        {
-            meshChanged_ = true;
-        }
+        meshState_ = meshPtr_ ? meshPtr_->readUpdate() : polyMesh::TOPO_CHANGE;
 
         reader_->UpdateProgress(0.05);
 
@@ -171,7 +173,7 @@ int Foam::vtkPVFoam::setTime(int nRequest, const double requestTimes[])
         Info<< "<end> setTime() - selectedTime="
             << Times[nearestIndex].name() << " index=" << timeIndex_
             << "/" << Times.size()
-            << " meshChanged=" << Switch(meshChanged_)
+            << " meshUpdateState=" << updateStateName(meshState_)
             << " fieldsChanged=" << Switch(fieldsChanged_) << endl;
     }
 
@@ -179,7 +181,20 @@ int Foam::vtkPVFoam::setTime(int nRequest, const double requestTimes[])
 }
 
 
-Foam::word Foam::vtkPVFoam::getPartName(const int partId)
+Foam::word Foam::vtkPVFoam::getPartName(const int partId) const
+{
+    if (selectedPartIds_.found(partId))
+    {
+        return getFoamName(selectedPartIds_[partId]);
+    }
+    else
+    {
+        return word::null;
+    }
+}
+
+
+Foam::word Foam::vtkPVFoam::getReaderPartName(const int partId) const
 {
     return getFoamName(reader_->GetPartArrayName(partId));
 }
@@ -199,7 +214,7 @@ Foam::vtkPVFoam::vtkPVFoam
     meshRegion_(polyMesh::defaultRegion),
     meshDir_(polyMesh::meshSubDir),
     timeIndex_(-1),
-    meshChanged_(true),
+    meshState_(polyMesh::TOPO_CHANGE),
     fieldsChanged_(true),
     rangeVolume_("unzoned"),
     rangePatches_("patch"),
@@ -334,7 +349,7 @@ void Foam::vtkPVFoam::updateInfo()
     // time of the vtkDataArraySelection, but the qt/paraview proxy
     // layer doesn't care about that anyhow.
 
-    stringList enabledEntries;
+    HashSet<string> enabledEntries;
     if (!partSelection->GetNumberOfArrays() && !meshPtr_)
     {
         // enable 'internalMesh' on the first call
@@ -356,10 +371,10 @@ void Foam::vtkPVFoam::updateInfo()
     updateInfoZones(partSelection);
     updateInfoLagrangian(partSelection);
 
-    // restore the enabled selections
+    // Adjust/restore the enabled selections
     setSelectedArrayEntries(partSelection, enabledEntries);
 
-    if (meshChanged_)
+    if (meshState_ != polyMesh::UNCHANGED)
     {
         fieldsChanged_ = true;
     }
@@ -408,37 +423,48 @@ void Foam::vtkPVFoam::Update
         }
 
         vtkDataArraySelection* selection = reader_->GetPartSelection();
-        label nElem = selection->GetNumberOfArrays();
+        const int n = selection->GetNumberOfArrays();
 
-        if (partStatus_.size() != nElem)
+        // All previously selected (enabled) names
+        HashSet<string> original;
+        forAllConstIters(selectedPartIds_, iter)
         {
-            partStatus_.setSize(nElem);
-            partStatus_ = false;
-            meshChanged_ = true;
+            original.insert(iter.object());
         }
 
-        // this needs fixing if we wish to re-use the datasets
-        partDataset_.setSize(nElem);
-        partDataset_ = -1;
+        selectedPartIds_.clear();
 
-        // Read the selected mesh parts (zones, patches ...) and add to list
-        forAll(partStatus_, partId)
+        for (int id=0; id < n; ++id)
         {
-            const int setting = selection->GetArraySetting(partId);
+            string str(selection->GetArrayName(id));
+            bool status = selection->GetArraySetting(id);
 
-            if (partStatus_[partId] != setting)
+            if (status)
             {
-                partStatus_[partId] = setting;
-                meshChanged_ = true;
+                selectedPartIds_.set(id, str); // id -> name
+
+                if (!original.erase(str))
+                {
+                    // New part, or newly enabled
+                    //? meshChanged_ = true;
+                }
+            }
+            else
+            {
+                if (original.erase(str))
+                {
+                    // Part disappeared, or newly disabled
+                    //? meshChanged_ = true;
+                }
             }
 
             if (debug > 1)
             {
-                Info<< "  part[" << partId << "] = "
-                    << partStatus_[partId]
-                    << " : " << selection->GetArrayName(partId) << endl;
+                Info<< "  part[" << id << "] = " << status
+                    << " : " << str << nl;
             }
         }
+
         if (debug)
         {
             Info<< "<end> updateMeshPartsStatus" << endl;
@@ -467,8 +493,7 @@ void Foam::vtkPVFoam::Update
             if (debug)
             {
                 Info<< "Creating OpenFOAM mesh for region " << meshRegion_
-                    << " at time=" << dbPtr_().timeName()
-                        << endl;
+                    << " at time=" << dbPtr_().timeName() << endl;
 
             }
 
@@ -483,7 +508,7 @@ void Foam::vtkPVFoam::Update
                 )
             );
 
-            meshChanged_ = true;
+            meshState_ = polyMesh::TOPO_CHANGE; // New mesh
         }
         else
         {
@@ -502,6 +527,20 @@ void Foam::vtkPVFoam::Update
 
     reader_->UpdateProgress(0.4);
 
+    // Update cached, saved, unneed values:
+    HashSet<string> nowActive;
+    forAllConstIters(selectedPartIds_, iter)
+    {
+        nowActive.insert(iter.object());
+    }
+
+    // Dispose of unneeded components
+    cachedVtp_.retain(nowActive);
+    cachedVtu_.retain(nowActive);
+
+    // Reset (expire) dataset ids
+    partDataset_.clear();
+
     // Convert meshes - start port0 at block=0
     int blockNo = 0;
 
@@ -549,21 +588,12 @@ void Foam::vtkPVFoam::Update
     }
     reader_->UpdateProgress(0.95);
 
-    meshChanged_ = fieldsChanged_ = false;
+    fieldsChanged_ = false;
+    meshState_ = polyMesh::UNCHANGED;
 
     // Standard memory cleanup
-    forAll(regionVtus_, i)
-    {
-        regionVtus_[i].clear();
-    }
-    forAll(zoneVtus_, i)
-    {
-        zoneVtus_[i].clear();
-    }
-    forAll(csetVtus_, i)
-    {
-        csetVtus_[i].clear();
-    }
+    cachedVtp_.clear();
+    cachedVtu_.clear();
 }
 
 
diff --git a/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoam.H b/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoam.H
index c6e365b8af..4a320affd2 100644
--- a/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoam.H
+++ b/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoam.H
@@ -160,7 +160,17 @@ class vtkPVFoam
             }
         };
 
-    typedef polyDecomp foamVtuData;
+        //- Bookkeeping for vtkPolyData
+        class foamVtpData
+        {
+        };
+
+        //- Bookkeeping for vtkUnstructuredGrid
+        class foamVtuData
+        :
+            public polyDecomp
+        {
+        };
 
 
     // Private Data
@@ -184,20 +194,26 @@ class vtkPVFoam
         int timeIndex_;
 
         //- Track changes in mesh geometry
-        bool meshChanged_;
+        enum polyMesh::readUpdateState meshState_;
 
         //- Track changes in fields
         bool fieldsChanged_;
 
-        //- Selected geometrical parts (internalMesh, patches, ...)
-        boolList partStatus_;
+        //- The index of selected parts mapped to their names
+        Map<string> selectedPartIds_;
 
         //- Datasets corresponding to selected geometrical pieces
-        //  a negative number indicates that no vtkmesh exists for this piece
-        labelList partDataset_;
+        Map<label> partDataset_;
+
+        //- Any information for 2D (VTP) geometries
+        HashTable<foamVtpData, string> cachedVtp_;
+
+        //- Cell maps and other information for 3D (VTU) geometries
+        HashTable<foamVtuData, string> cachedVtu_;
 
         //- First instance and size of various mesh parts
-        //  used to index into partStatus_ and partDataset_
+        //  used to index into selectedPartIds and thus indirectly into
+        //  cachedVtp, cachedVtu and partDataset
         arrayRange rangeVolume_;
         arrayRange rangePatches_;
         arrayRange rangeLagrangian_;
@@ -208,16 +224,6 @@ class vtkPVFoam
         arrayRange rangeFaceSets_;
         arrayRange rangePointSets_;
 
-        //- Decomposed cells information (mesh regions)
-        //  TODO: regions
-        List<foamVtuData> regionVtus_;
-
-        //- Decomposed cells information (cellZone meshes)
-        List<foamVtuData> zoneVtus_;
-
-        //- Decomposed cells information (cellSet meshes)
-        List<foamVtuData> csetVtus_;
-
         //- List of patch names for rendering to window
         List<vtkSmartPointer<vtkTextActor>> patchTextActors_;
 
@@ -230,19 +236,24 @@ class vtkPVFoam
       // Update information helper functions
 
         //- Internal mesh info
-        void updateInfoInternalMesh(vtkDataArraySelection*);
+        void updateInfoInternalMesh(vtkDataArraySelection* select);
 
         //- Lagrangian info
-        void updateInfoLagrangian(vtkDataArraySelection*);
+        void updateInfoLagrangian(vtkDataArraySelection* select);
 
-        //- Patch info
-        void updateInfoPatches(vtkDataArraySelection*, stringList&);
+        //- Patch info, modifies enabledEntries
+        void updateInfoPatches
+        (
+            vtkDataArraySelection* select,
+            HashSet<string>& enabledEntries
+        );
 
         //- Set info
-        void updateInfoSets(vtkDataArraySelection*);
+        void updateInfoSets(vtkDataArraySelection* select);
 
         //- Zone info
-        void updateInfoZones(vtkDataArraySelection*);
+        void updateInfoZones(vtkDataArraySelection* select);
+
 
         //- Get non-empty zone names for zoneType from file
         wordList getZoneNames(const word& zoneType) const;
@@ -395,8 +406,7 @@ class vtkPVFoam
             const GeometricField<Type, fvPatchField, volMesh>& fld,
             autoPtr<GeometricField<Type, pointPatchField, pointMesh>>& ptfPtr,
             vtkMultiBlockDataSet* output,
-            const arrayRange& range,
-            const List<foamVtuData>& vtuDataList
+            const arrayRange& range
         );
 
         //- Lagrangian fields - all types
@@ -423,8 +433,7 @@ class vtkPVFoam
         (
             const GeometricField<Type, pointPatchField, pointMesh>& pfld,
             vtkMultiBlockDataSet* output,
-            const arrayRange& range,
-            const List<foamVtuData>& vtuDataList
+            const arrayRange& range
         );
 
         //- Point field
@@ -447,8 +456,12 @@ class vtkPVFoam
             const hashedWordList& retain
         );
 
+
+        //- Get the first word from selectedPartIds_
+        word getPartName(const int partId) const;
+
         //- Get the first word from the reader 'parts' selection
-        word getPartName(const int partId);
+        word getReaderPartName(const int partId) const;
 
 
     // Constructors
diff --git a/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoamFieldTemplates.C b/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoamFieldTemplates.C
index db477759f6..70d0bdabe4 100644
--- a/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoamFieldTemplates.C
+++ b/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoamFieldTemplates.C
@@ -84,8 +84,7 @@ void Foam::vtkPVFoam::convertVolField
         fld,
         ptfPtr,
         output,
-        rangeVolume_,
-        regionVtus_
+        rangeVolume_
     );
 
     // Convert activated cellZones
@@ -94,8 +93,7 @@ void Foam::vtkPVFoam::convertVolField
         fld,
         ptfPtr,
         output,
-        rangeCellZones_,
-        zoneVtus_
+        rangeCellZones_
     );
 
     // Convert activated cellSets
@@ -104,21 +102,30 @@ void Foam::vtkPVFoam::convertVolField
         fld,
         ptfPtr,
         output,
-        rangeCellSets_,
-        csetVtus_
+        rangeCellSets_
     );
 
 
     //
     // Convert patches - if activated
+    // - skip field conversion for groups
     //
     for (auto partId : rangePatches_)
     {
+        if
+        (
+            !selectedPartIds_.found(partId)
+         || selectedPartIds_[partId].startsWith("group/")
+        )
+        {
+            continue;
+        }
+
         const word patchName = getPartName(partId);
-        const label datasetNo = partDataset_[partId];
+        const label datasetNo = partDataset_.lookup(partId, -1);
         const label patchId = patches.findPatchID(patchName);
 
-        if (!partStatus_[partId] || patchId < 0)
+        if (patchId < 0)
         {
             continue;
         }
@@ -199,10 +206,15 @@ void Foam::vtkPVFoam::convertVolField
     //
     for (auto partId : rangeFaceZones_)
     {
-        const word zoneName = getPartName(partId);
-        const label datasetNo = partDataset_[partId];
+        if (!selectedPartIds_.found(partId))
+        {
+            continue;
+        }
 
-        if (!partStatus_[partId] || datasetNo < 0)
+        const word zoneName = getPartName(partId);
+        const label datasetNo = partDataset_.lookup(partId, -1);
+
+        if (datasetNo < 0)
         {
             continue;
         }
@@ -239,14 +251,14 @@ void Foam::vtkPVFoam::convertVolField
     //
     for (auto partId : rangeFaceSets_)
     {
-        const word selectName = getPartName(partId);
-        const label datasetNo = partDataset_[partId];
-
-        if (!partStatus_[partId])
+        if (!selectedPartIds_.found(partId))
         {
             continue;
         }
 
+        const word selectName = getPartName(partId);
+        const label datasetNo = partDataset_.lookup(partId, -1);
+
         vtkPolyData* vtkmesh = getDataFromBlock<vtkPolyData>
         (
             output, rangeFaceSets_, datasetNo
@@ -373,23 +385,23 @@ void Foam::vtkPVFoam::convertVolFieldBlock
     const GeometricField<Type, fvPatchField, volMesh>& fld,
     autoPtr<GeometricField<Type, pointPatchField, pointMesh>>& ptfPtr,
     vtkMultiBlockDataSet* output,
-    const arrayRange& range,
-    const List<foamVtuData>& vtuDataList
+    const arrayRange& range
 )
 {
     for (auto partId : range)
     {
-        const label datasetNo = partDataset_[partId];
-
-        if (!partStatus_[partId])
+        if (!selectedPartIds_.found(partId))
         {
             continue;
         }
 
+        const auto& longName = selectedPartIds_[partId];
+        const label datasetNo = partDataset_.lookup(partId, -1);
+
         vtkUnstructuredGrid* vtkmesh =
             getDataFromBlock<vtkUnstructuredGrid>(output, range, datasetNo);
 
-        if (!vtkmesh)
+        if (!vtkmesh || !cachedVtu_.found(longName))
         {
             continue;
         }
@@ -397,13 +409,17 @@ void Foam::vtkPVFoam::convertVolFieldBlock
         vtkSmartPointer<vtkFloatArray> cdata = convertVolFieldToVTK
         (
             fld,
-            vtuDataList[datasetNo]
+            cachedVtu_[longName]
         );
         vtkmesh->GetCellData()->AddArray(cdata);
 
         if (ptfPtr.valid())
         {
-            convertPointField(vtkmesh, ptfPtr(), fld, vtuDataList[datasetNo]);
+            convertPointField
+            (
+                vtkmesh, ptfPtr(), fld,
+                cachedVtu_[longName]
+            );
         }
     }
 }
@@ -446,44 +462,53 @@ void Foam::vtkPVFoam::convertPointFields
         GeometricField<Type, pointPatchField, pointMesh> pfld(*iter(), pMesh);
 
 
-        // Convert activated internalMesh regions
+        // Convert internalMesh (if selected)
         convertPointFieldBlock
         (
             pfld,
             output,
-            rangeVolume_,
-            regionVtus_
+            rangeVolume_
         );
 
-        // Convert activated cellZones
+        // Convert (selected) cellZones
         convertPointFieldBlock
         (
             pfld,
             output,
-            rangeCellZones_,
-            zoneVtus_
+            rangeCellZones_
         );
 
-        // Convert activated cellSets
+        // Convert (selected) cellSets
         convertPointFieldBlock
         (
             pfld,
             output,
-            rangeCellSets_,
-            csetVtus_
+            rangeCellSets_
         );
 
 
         //
-        // Convert patches - if activated
+        // Convert patches (if selected)
         //
         for (auto partId : rangePatches_)
         {
+            if (!selectedPartIds_.found(partId))
+            {
+                continue;
+            }
+            const auto& longName = selectedPartIds_[partId];
+
+            if (longName.startsWith("group/"))
+            {
+                // Skip patch-groups
+                continue;
+            }
+
             const word patchName = getPartName(partId);
-            const label datasetNo = partDataset_[partId];
+            const label datasetNo = partDataset_.lookup(partId, -1);
             const label patchId = patches.findPatchID(patchName);
 
-            if (!partStatus_[partId] || patchId < 0)
+            if (patchId < 0)
             {
                 continue;
             }
@@ -506,15 +531,20 @@ void Foam::vtkPVFoam::convertPointFields
         }
 
         //
-        // Convert faceZones - if activated
+        // Convert (selected) faceZones
         //
         for (auto partId : rangeFaceZones_)
         {
+            if (!selectedPartIds_.found(partId))
+            {
+                continue;
+            }
+
             const word zoneName = getPartName(partId);
-            const label datasetNo = partDataset_[partId];
+            const label datasetNo = partDataset_.lookup(partId, -1);
             const label zoneId = mesh.faceZones().findZoneID(zoneName);
 
-            if (!partStatus_[partId] || zoneId < 0)
+            if (zoneId < 0)
             {
                 continue;
             }
@@ -552,34 +582,35 @@ void Foam::vtkPVFoam::convertPointFieldBlock
 (
     const GeometricField<Type, pointPatchField, pointMesh>& pfld,
     vtkMultiBlockDataSet* output,
-    const arrayRange& range,
-    const List<foamVtuData>& vtuDataList
+    const arrayRange& range
 )
 {
     for (auto partId : range)
     {
-        const label datasetNo = partDataset_[partId];
-
-        if (!partStatus_[partId])
+        if (!selectedPartIds_.found(partId))
         {
             continue;
         }
 
+        const auto& longName = selectedPartIds_[partId];
+        const label datasetNo = partDataset_.lookup(partId, -1);
+
         vtkUnstructuredGrid* vtkmesh = getDataFromBlock<vtkUnstructuredGrid>
         (
             output, range, datasetNo
         );
 
-        if (vtkmesh)
+        if (!vtkmesh || !cachedVtu_.found(longName))
         {
             convertPointField
             (
                 vtkmesh,
                 pfld,
                 GeometricField<Type, fvPatchField, volMesh>::null(),
-                vtuDataList[datasetNo]
+                cachedVtu_[longName]
             );
         }
+
     }
 }
 
@@ -878,16 +909,16 @@ Foam::vtkPVFoam::convertVolFieldToVTK
     }
 
     float vec[nComp];
-    forAll(cellMap, i)
+    forAll(cellMap, idx)
     {
-        const Type& t = fld[cellMap[i]];
+        const Type& t = fld[cellMap[idx]];
         for (direction d=0; d<nComp; ++d)
         {
             vec[d] = component(t, d);
         }
         foamPvFields::remapTuple<Type>(vec);
 
-        fldData->SetTuple(i, vec);
+        fldData->SetTuple(idx, vec);
     }
 
     return fldData;
diff --git a/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoamFields.C b/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoamFields.C
index cbf43d1f4e..697737d74d 100644
--- a/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoamFields.C
+++ b/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoamFields.C
@@ -226,10 +226,15 @@ void Foam::vtkPVFoam::convertLagrangianFields
 
     for (auto partId : range)
     {
-        const word  cloudName = getPartName(partId);
-        const label datasetNo = partDataset_[partId];
+        if (!selectedPartIds_.found(partId))
+        {
+            continue;
+        }
 
-        if (!partStatus_[partId] || datasetNo < 0)
+        const word  cloudName = getPartName(partId);
+        const label datasetNo = partDataset_.lookup(partId, -1);
+
+        if (datasetNo < 0)
         {
             continue;
         }
diff --git a/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoamMesh.C b/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoamMesh.C
index cca044671b..9e202a352e 100644
--- a/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoamMesh.C
+++ b/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoamMesh.C
@@ -53,9 +53,6 @@ void Foam::vtkPVFoam::convertMeshVolume
     label datasetNo = 0;       // restart at dataset 0
     const fvMesh& mesh = *meshPtr_;
 
-    // resize for decomposed polyhedra
-    regionVtus_.setSize(range.size());
-
     if (debug)
     {
         Info<< "<beg> convertMeshVolume" << endl;
@@ -66,23 +63,24 @@ void Foam::vtkPVFoam::convertMeshVolume
     // this looks like more than one part, but it isn't
     for (auto partId : range)
     {
-        const word partName = "internalMesh";
-
-        if (!partStatus_[partId])
+        if (!selectedPartIds_.found(partId))
         {
             continue;
         }
 
+        const auto& longName = selectedPartIds_[partId];
+        const word partName = getPartName(partId);
+
         vtkSmartPointer<vtkUnstructuredGrid> vtkmesh = volumeVTKMesh
         (
             mesh,
-            regionVtus_[datasetNo]
+            cachedVtu_(longName)
         );
 
         if (vtkmesh)
         {
             addToBlock(output, vtkmesh, range, datasetNo, partName);
-            partDataset_[partId] = datasetNo++;
+            partDataset_.set(partId, datasetNo++);
         }
     }
 
@@ -119,20 +117,20 @@ void Foam::vtkPVFoam::convertMeshLagrangian
 
     for (auto partId : range)
     {
-        const word cloudName = getPartName(partId);
-
-        if (!partStatus_[partId])
+        if (!selectedPartIds_.found(partId))
         {
             continue;
         }
 
+        const word cloudName = getPartName(partId);
+
         vtkSmartPointer<vtkPolyData> vtkmesh =
             lagrangianVTKMesh(mesh, cloudName);
 
         if (vtkmesh)
         {
             addToBlock(output, vtkmesh, range, datasetNo, cloudName);
-            partDataset_[partId] = datasetNo++;
+            partDataset_.set(partId, datasetNo++);
         }
     }
 
@@ -170,30 +168,28 @@ void Foam::vtkPVFoam::convertMeshPatches
 
     for (auto partId : range)
     {
-        if (!partStatus_[partId])
+        if (!selectedPartIds_.found(partId))
         {
             continue;
         }
-
-        const word patchName = getPartName(partId);
-
-        labelHashSet
-            patchIds(patches.patchSet(List<wordRe>(1, wordRe(patchName))));
-
-        if (debug)
-        {
-            Info<< "Creating VTK mesh for patches [" << patchIds <<"] "
-                << patchName << endl;
-        }
+        const auto& longName = selectedPartIds_[partId];
+        const word partName = getPartName(partId);
 
         vtkSmartPointer<vtkPolyData> vtkmesh;
-        if (patchIds.size() == 1)
-        {
-            vtkmesh = patchVTKMesh(patchName, patches[patchIds.begin().key()]);
-        }
-        else
+
+        if (longName.startsWith("group/"))
         {
             // Patch group. Collect patch faces.
+
+            const labelList& patchIds =
+                patches.groupPatchIDs().lookup(partName, labelList());
+
+            if (debug)
+            {
+                Info<< "Creating VTK mesh for patches [" << patchIds <<"] "
+                    << longName << endl;
+            }
+
             label sz = 0;
             for (auto id : patchIds)
             {
@@ -210,23 +206,37 @@ void Foam::vtkPVFoam::convertMeshPatches
                 }
             }
 
-            uindirectPrimitivePatch pp
-            (
-                UIndirectList<face>
+            if (faceLabels.size())
+            {
+                uindirectPrimitivePatch pp
                 (
-                    mesh.faces(),
-                    faceLabels
-                ),
-                mesh.points()
-            );
+                    UIndirectList<face>(mesh.faces(), faceLabels),
+                    mesh.points()
+                );
 
-            vtkmesh = patchVTKMesh(patchName, pp);
+                vtkmesh = patchVTKMesh(partName, pp);
+            }
+        }
+        else
+        {
+            const label patchId = patches.findPatchID(partName);
+
+            if (debug)
+            {
+                Info<< "Creating VTK mesh for patch [" << patchId <<"] "
+                    << partName << endl;
+            }
+
+            if (patchId >= 0)
+            {
+                vtkmesh = patchVTKMesh(partName, patches[patchId]);
+            }
         }
 
         if (vtkmesh)
         {
-            addToBlock(output, vtkmesh, range, datasetNo, patchName);
-            partDataset_[partId] = datasetNo++;
+            addToBlock(output, vtkmesh, range, datasetNo, partName);
+            partDataset_.set(partId, datasetNo++);
         }
     }
 
@@ -255,9 +265,6 @@ void Foam::vtkPVFoam::convertMeshCellZones
     label datasetNo = 0;       // restart at dataset 0
     const fvMesh& mesh = *meshPtr_;
 
-    // resize for decomposed polyhedra
-    zoneVtus_.setSize(range.size());
-
     if (range.empty())
     {
         return;
@@ -272,10 +279,16 @@ void Foam::vtkPVFoam::convertMeshCellZones
     const cellZoneMesh& zMesh = mesh.cellZones();
     for (auto partId : range)
     {
+        if (!selectedPartIds_.found(partId))
+        {
+            continue;
+        }
+
+        const auto& longName = selectedPartIds_[partId];
         const word zoneName = getPartName(partId);
         const label  zoneId = zMesh.findZoneID(zoneName);
 
-        if (!partStatus_[partId] || zoneId < 0)
+        if (zoneId < 0)
         {
             continue;
         }
@@ -292,28 +305,28 @@ void Foam::vtkPVFoam::convertMeshCellZones
         vtkSmartPointer<vtkUnstructuredGrid> vtkmesh = volumeVTKMesh
         (
             subsetter.subMesh(),
-            zoneVtus_[datasetNo]
+            cachedVtu_(longName)
         );
 
         if (vtkmesh)
         {
-            // cellMap + addPointCellLabels must contain global cell ids
+            // Convert cellMap, addPointCellLabels to global cell ids
             inplaceRenumber
             (
                 subsetter.cellMap(),
-                zoneVtus_[datasetNo].cellMap()
+                cachedVtu_[longName].cellMap()
             );
             inplaceRenumber
             (
                 subsetter.cellMap(),
-                zoneVtus_[datasetNo].additionalIds()
+                cachedVtu_[longName].additionalIds()
             );
 
             // copy pointMap as well, otherwise pointFields fail
-            zoneVtus_[datasetNo].pointMap() = subsetter.pointMap();
+            cachedVtu_[longName].pointMap() = subsetter.pointMap();
 
             addToBlock(output, vtkmesh, range, datasetNo, zoneName);
-            partDataset_[partId] = datasetNo++;
+            partDataset_.set(partId, datasetNo++);
         }
     }
 
@@ -342,9 +355,6 @@ void Foam::vtkPVFoam::convertMeshCellSets
     label datasetNo = 0;       // restart at dataset 0
     const fvMesh& mesh = *meshPtr_;
 
-    // resize for decomposed polyhedra
-    csetVtus_.setSize(range.size());
-
     if (debug)
     {
         Info<< "<beg> convertMeshCellSets" << endl;
@@ -353,13 +363,14 @@ void Foam::vtkPVFoam::convertMeshCellSets
 
     for (auto partId : range)
     {
-        const word partName = getPartName(partId);
-
-        if (!partStatus_[partId])
+        if (!selectedPartIds_.found(partId))
         {
             continue;
         }
 
+        const auto& longName = selectedPartIds_[partId];
+        const word partName = getPartName(partId);
+
         if (debug)
         {
             Info<< "Creating VTK mesh for cellSet=" << partName << endl;
@@ -372,28 +383,28 @@ void Foam::vtkPVFoam::convertMeshCellSets
         vtkSmartPointer<vtkUnstructuredGrid> vtkmesh = volumeVTKMesh
         (
             subsetter.subMesh(),
-            csetVtus_[datasetNo]
+            cachedVtu_(longName)
         );
 
         if (vtkmesh)
         {
-            // cellMap + addPointCellLabels must contain global cell ids
+            // Convert cellMap, addPointCellLabels to global cell ids
             inplaceRenumber
             (
                 subsetter.cellMap(),
-                csetVtus_[datasetNo].cellMap()
+                cachedVtu_[longName].cellMap()
             );
             inplaceRenumber
             (
                 subsetter.cellMap(),
-                csetVtus_[datasetNo].additionalIds()
+                cachedVtu_[longName].additionalIds()
             );
 
             // copy pointMap as well, otherwise pointFields fail
-            csetVtus_[datasetNo].pointMap() = subsetter.pointMap();
+            cachedVtu_[longName].pointMap() = subsetter.pointMap();
 
             addToBlock(output, vtkmesh, range, datasetNo, partName);
-            partDataset_[partId] = datasetNo++;
+            partDataset_.set(partId, datasetNo++);
         }
     }
 
@@ -436,10 +447,15 @@ void Foam::vtkPVFoam::convertMeshFaceZones
     const faceZoneMesh& zMesh = mesh.faceZones();
     for (auto partId : range)
     {
+        if (!selectedPartIds_.found(partId))
+        {
+            continue;
+        }
+
         const word zoneName = getPartName(partId);
         const label  zoneId = zMesh.findZoneID(zoneName);
 
-        if (!partStatus_[partId] || zoneId < 0)
+        if (zoneId < 0)
         {
             continue;
         }
@@ -456,7 +472,7 @@ void Foam::vtkPVFoam::convertMeshFaceZones
         if (vtkmesh)
         {
             addToBlock(output, vtkmesh, range, datasetNo, zoneName);
-            partDataset_[partId] = datasetNo++;
+            partDataset_.set(partId, datasetNo++);
         }
     }
 
@@ -493,26 +509,24 @@ void Foam::vtkPVFoam::convertMeshFaceSets
 
     for (auto partId : range)
     {
-        const word partName = getPartName(partId);
-
-        if (!partStatus_[partId])
+        if (!selectedPartIds_.found(partId))
         {
             continue;
         }
 
+        const word partName = getPartName(partId);
+
         if (debug)
         {
             Info<< "Creating VTK mesh for faceSet=" << partName << endl;
         }
 
         // faces in sorted order for more reliability
+        const labelList faceLabels = faceSet(mesh, partName).sortedToc();
+
         uindirectPrimitivePatch p
         (
-            UIndirectList<face>
-            (
-                mesh.faces(),
-                faceSet(mesh, partName).sortedToc()
-            ),
+            UIndirectList<face>(mesh.faces(), faceLabels),
             mesh.points()
         );
 
@@ -527,7 +541,7 @@ void Foam::vtkPVFoam::convertMeshFaceSets
         if (vtkmesh)
         {
             addToBlock(output, vtkmesh, range, datasetNo, partName);
-            partDataset_[partId] = datasetNo++;
+            partDataset_.set(partId, datasetNo++);
         }
     }
 
@@ -567,10 +581,15 @@ void Foam::vtkPVFoam::convertMeshPointZones
         const pointZoneMesh& zMesh = mesh.pointZones();
         for (auto partId : range)
         {
+            if (!selectedPartIds_.found(partId))
+            {
+                continue;
+            }
+
             const word zoneName = getPartName(partId);
             const label zoneId = zMesh.findZoneID(zoneName);
 
-            if (!partStatus_[partId] || zoneId < 0)
+            if (zoneId < 0)
             {
                 continue;
             }
@@ -600,7 +619,7 @@ void Foam::vtkPVFoam::convertMeshPointZones
             if (vtkmesh)
             {
                 addToBlock(output, vtkmesh, range, datasetNo, zoneName);
-                partDataset_[partId] = datasetNo++;
+                partDataset_.set(partId, datasetNo++);
             }
         }
     }
@@ -619,7 +638,6 @@ void Foam::vtkPVFoam::convertMeshPointZones
 }
 
 
-
 void Foam::vtkPVFoam::convertMeshPointSets
 (
     vtkMultiBlockDataSet* output,
@@ -639,13 +657,13 @@ void Foam::vtkPVFoam::convertMeshPointSets
 
     for (auto partId : range)
     {
-        const word partName = getPartName(partId);
-
-        if (!partStatus_[partId])
+        if (!selectedPartIds_.found(partId))
         {
             continue;
         }
 
+        const word partName = getPartName(partId);
+
         if (debug)
         {
             Info<< "Creating VTK mesh for pointSet=" << partName << endl;
@@ -676,7 +694,7 @@ void Foam::vtkPVFoam::convertMeshPointSets
         if (vtkmesh)
         {
             addToBlock(output, vtkmesh, range, datasetNo, partName);
-            partDataset_[partId] = datasetNo++;
+            partDataset_.set(partId, datasetNo++);
         }
     }
 
diff --git a/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoamUpdateInfo.C b/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoamUpdateInfo.C
index 338fc0c865..d344d949d4 100644
--- a/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoamUpdateInfo.C
+++ b/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoamUpdateInfo.C
@@ -136,7 +136,7 @@ Foam::wordList Foam::vtkPVFoam::getZoneNames(const word& zoneType) const
 
 void Foam::vtkPVFoam::updateInfoInternalMesh
 (
-    vtkDataArraySelection* arraySelection
+    vtkDataArraySelection* select
 )
 {
     if (debug)
@@ -146,8 +146,8 @@ void Foam::vtkPVFoam::updateInfoInternalMesh
 
     // Determine mesh parts (internalMesh, patches...)
     //- Add internal mesh as first entry
-    rangeVolume_.reset(arraySelection->GetNumberOfArrays(), 1);
-    arraySelection->AddArray("internalMesh");
+    rangeVolume_.reset(select->GetNumberOfArrays(), 1);
+    select->AddArray("internalMesh");
 
     if (debug)
     {
@@ -158,7 +158,7 @@ void Foam::vtkPVFoam::updateInfoInternalMesh
 
 void Foam::vtkPVFoam::updateInfoLagrangian
 (
-    vtkDataArraySelection* arraySelection
+    vtkDataArraySelection* select
 )
 {
     if (debug)
@@ -167,7 +167,6 @@ void Foam::vtkPVFoam::updateInfoLagrangian
             << "    " << dbPtr_->timePath()/cloud::prefix << endl;
     }
 
-
     // use the db directly since this might be called without a mesh,
     // but the region must get added back in
     fileName lagrangianPrefix(cloud::prefix);
@@ -182,11 +181,11 @@ void Foam::vtkPVFoam::updateInfoLagrangian
         readDir(dbPtr_->timePath()/lagrangianPrefix, fileName::DIRECTORY)
     );
 
-    rangeLagrangian_.reset(arraySelection->GetNumberOfArrays());
+    rangeLagrangian_.reset(select->GetNumberOfArrays());
     forAll(cloudDirs, cloudi)
     {
         // Add cloud to GUI list
-        arraySelection->AddArray
+        select->AddArray
         (
             ("lagrangian/" + cloudDirs[cloudi]).c_str()
         );
@@ -202,8 +201,8 @@ void Foam::vtkPVFoam::updateInfoLagrangian
 
 void Foam::vtkPVFoam::updateInfoPatches
 (
-    vtkDataArraySelection* arraySelection,
-    stringList& enabledEntries
+    vtkDataArraySelection* select,
+    HashSet<string>& enabledEntries
 )
 {
     if (debug)
@@ -212,14 +211,13 @@ void Foam::vtkPVFoam::updateInfoPatches
             << " [meshPtr=" << (meshPtr_ ? "set" : "null") << "]" << endl;
     }
 
-    HashSet<string> enabledEntriesSet(enabledEntries);
-
-    rangePatches_.reset(arraySelection->GetNumberOfArrays());
+    rangePatches_.reset(select->GetNumberOfArrays());
 
     if (meshPtr_)
     {
         const polyBoundaryMesh& patches = meshPtr_->boundaryMesh();
         const HashTable<labelList>& groups = patches.groupPatchIDs();
+        DynamicList<string> displayNames(groups.size());
 
         // Add (non-zero) patch groups to the list of mesh parts
         // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -243,29 +241,38 @@ void Foam::vtkPVFoam::updateInfoPatches
 
             // Valid patch if nFace > 0 - add patch to GUI list
             const string dpyName = "group/" + groupName;
-            arraySelection->AddArray(dpyName.c_str());
-            ++rangePatches_;
+            displayNames.append(dpyName);
 
-            if (enabledEntriesSet.found(dpyName))
+            // Optionally replace group with patch name selections
+            // - must remove the group from the select itself, otherwise
+            //   it can toggle on, but not toggle off very well
+            if
+            (
+                !reader_->GetShowGroupsOnly()
+             && enabledEntries.erase(dpyName)
+            )
             {
-                if (!reader_->GetShowGroupsOnly())
+                for (auto patchId : patchIDs)
                 {
-                    enabledEntriesSet.erase(dpyName);
-                    for (auto patchId : patchIDs)
+                    const polyPatch& pp = patches[patchId];
+                    if (pp.size())
                     {
-                        const polyPatch& pp = patches[patchId];
-                        if (pp.size())
-                        {
-                            enabledEntriesSet.insert
-                            (
-                                "patch/" + pp.name()
-                            );
-                        }
+                        enabledEntries.insert
+                        (
+                            "patch/" + pp.name()
+                        );
                     }
                 }
             }
         }
 
+        // Sort group names
+        Foam::sort(displayNames);
+        for (const auto& name : displayNames)
+        {
+            select->AddArray(name.c_str());
+            ++rangePatches_;
+        }
 
         // Add (non-zero) patches to the list of mesh parts
         // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -279,7 +286,7 @@ void Foam::vtkPVFoam::updateInfoPatches
                 if (pp.size())
                 {
                     // Add patch to GUI list
-                    arraySelection->AddArray
+                    select->AddArray
                     (
                         ("patch/" + pp.name()).c_str()
                     );
@@ -308,36 +315,24 @@ void Foam::vtkPVFoam::updateInfoPatches
             false
         );
 
-        // this should only ever fail if the mesh region doesn't exist
+        // This should only ever fail if the mesh region doesn't exist
         if (ioObj.typeHeaderOk<polyBoundaryMesh>(true, false))
         {
             polyBoundaryMeshEntries patchEntries(ioObj);
 
-            // Read patches and determine sizes
-            // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
+            // Read patches, determine sizes and patch groups
             wordList names(patchEntries.size());
             labelList sizes(patchEntries.size());
-
-            forAll(patchEntries, patchi)
-            {
-                const dictionary& patchDict = patchEntries[patchi].dict();
-
-                sizes[patchi] = readLabel(patchDict.lookup("nFaces"));
-                names[patchi] = patchEntries[patchi].keyword();
-            }
-
-
-            // Add (non-zero) patch groups to the list of mesh parts
-            // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-            HashTable<labelHashSet> groups(patchEntries.size());
+            HashTable<labelHashSet> groups(2*patchEntries.size());
 
             forAll(patchEntries, patchi)
             {
                 const dictionary& patchDict = patchEntries[patchi].dict();
                 wordList groupNames;
 
+                sizes[patchi] = readLabel(patchDict.lookup("nFaces"));
+                names[patchi] = patchEntries[patchi].keyword();
+
                 if
                 (
                     sizes[patchi]  // Valid patch if nFace > 0
@@ -351,26 +346,31 @@ void Foam::vtkPVFoam::updateInfoPatches
                 }
             }
 
+
+            // Add (non-zero) patch groups to the list of mesh parts
+            // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+            DynamicList<string> displayNames(groups.size());
+
             forAllConstIters(groups, iter)
             {
                 const auto& groupName = iter.key();
                 const auto& patchIDs  = iter.object();
 
                 const string dpyName = "group/" + groupName;
-                arraySelection->AddArray(dpyName.c_str());
-                ++rangePatches_;
+                displayNames.append(dpyName);
 
-                // Optionally replace with patch name selection
+                // Optionally replace group with patch name selections
+                // - must remove the group from the select itself, otherwise
+                //   it can toggle on, but not toggle off very well
                 if
                 (
-                    enabledEntriesSet.found(dpyName)
-                 && !reader_->GetShowGroupsOnly()
+                    !reader_->GetShowGroupsOnly()
+                 && enabledEntries.erase(dpyName)
                 )
                 {
-                    enabledEntriesSet.erase(dpyName);
                     for (auto patchId : patchIDs)
                     {
-                        enabledEntriesSet.insert
+                        enabledEntries.insert
                         (
                             "patch/" + names[patchId]
                         );
@@ -378,6 +378,13 @@ void Foam::vtkPVFoam::updateInfoPatches
                 }
             }
 
+            // Sort group names
+            Foam::sort(displayNames);
+            for (const auto& name : displayNames)
+            {
+                select->AddArray(name.c_str());
+                ++rangePatches_;
+            }
 
             // Add (non-zero) patches to the list of mesh parts
             // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -389,7 +396,7 @@ void Foam::vtkPVFoam::updateInfoPatches
                     // Valid patch if nFace > 0 - add patch to GUI list
                     if (sizes[patchi])
                     {
-                        arraySelection->AddArray
+                        select->AddArray
                         (
                             ("patch/" + names[patchi]).c_str()
                         );
@@ -400,9 +407,6 @@ void Foam::vtkPVFoam::updateInfoPatches
         }
     }
 
-    // Update enabled entries in case of group selection
-    enabledEntries = enabledEntriesSet.toc();
-
     if (debug)
     {
         Info<< "<end> updateInfoPatches" << endl;
@@ -412,7 +416,7 @@ void Foam::vtkPVFoam::updateInfoPatches
 
 void Foam::vtkPVFoam::updateInfoZones
 (
-    vtkDataArraySelection* arraySelection
+    vtkDataArraySelection* select
 )
 {
     if (!reader_->GetIncludeZones())
@@ -440,10 +444,10 @@ void Foam::vtkPVFoam::updateInfoZones
         namesLst = getZoneNames("cellZones");
     }
 
-    rangeCellZones_.reset(arraySelection->GetNumberOfArrays());
+    rangeCellZones_.reset(select->GetNumberOfArrays());
     forAll(namesLst, elemI)
     {
-        arraySelection->AddArray
+        select->AddArray
         (
             ("cellZone/" + namesLst[elemI]).c_str()
         );
@@ -463,10 +467,10 @@ void Foam::vtkPVFoam::updateInfoZones
         namesLst = getZoneNames("faceZones");
     }
 
-    rangeFaceZones_.reset(arraySelection->GetNumberOfArrays());
+    rangeFaceZones_.reset(select->GetNumberOfArrays());
     forAll(namesLst, elemI)
     {
-        arraySelection->AddArray
+        select->AddArray
         (
             ("faceZone/" + namesLst[elemI]).c_str()
         );
@@ -486,10 +490,10 @@ void Foam::vtkPVFoam::updateInfoZones
         namesLst = getZoneNames("pointZones");
     }
 
-    rangePointZones_.reset(arraySelection->GetNumberOfArrays());
+    rangePointZones_.reset(select->GetNumberOfArrays());
     forAll(namesLst, elemI)
     {
-        arraySelection->AddArray
+        select->AddArray
         (
             ("pointZone/" + namesLst[elemI]).c_str()
         );
@@ -505,7 +509,7 @@ void Foam::vtkPVFoam::updateInfoZones
 
 void Foam::vtkPVFoam::updateInfoSets
 (
-    vtkDataArraySelection* arraySelection
+    vtkDataArraySelection* select
 )
 {
     if (!reader_->GetIncludeSets())
@@ -545,26 +549,26 @@ void Foam::vtkPVFoam::updateInfoSets
     }
 
 
-    rangeCellSets_.reset(arraySelection->GetNumberOfArrays());
+    rangeCellSets_.reset(select->GetNumberOfArrays());
     rangeCellSets_ += addToSelection<cellSet>
     (
-        arraySelection,
+        select,
         objects,
         "cellSet/"
     );
 
-    rangeFaceSets_.reset(arraySelection->GetNumberOfArrays());
+    rangeFaceSets_.reset(select->GetNumberOfArrays());
     rangeFaceSets_ += addToSelection<faceSet>
     (
-        arraySelection,
+        select,
         objects,
         "faceSet/"
     );
 
-    rangePointSets_.reset(arraySelection->GetNumberOfArrays());
+    rangePointSets_.reset(select->GetNumberOfArrays());
     rangePointSets_ += addToSelection<pointSet>
     (
-        arraySelection,
+        select,
         objects,
         "pointSet/"
     );
@@ -586,8 +590,8 @@ void Foam::vtkPVFoam::updateInfoLagrangianFields
         Info<< "<beg> updateInfoLagrangianFields" << endl;
     }
 
-    // preserve the enabled selections
-    stringList enabledEntries = getSelectedArrayEntries(select);
+    // Preserve the enabled selections
+    HashSet<string> enabledEntries = getSelectedArrayEntries(select);
     select->RemoveAllArrays();
 
     // TODO - currently only get fields from ONE cloud
@@ -600,8 +604,9 @@ void Foam::vtkPVFoam::updateInfoLagrangianFields
         return;
     }
 
-    int partId = range.start();
-    word cloudName = getPartName(partId);
+    // Add Lagrangian fields even if particles are not enabled?
+    const int partId = range.start();
+    const word cloudName = getReaderPartName(partId);
 
     // use the db directly since this might be called without a mesh,
     // but the region must get added back in
@@ -625,7 +630,7 @@ void Foam::vtkPVFoam::updateInfoLagrangianFields
     addToSelection<IOField<symmTensor>>(select, objects);
     addToSelection<IOField<tensor>>(select, objects);
 
-    // restore the enabled selections
+    // Restore the enabled selections
     setSelectedArrayEntries(select, enabledEntries);
 
     if (debug > 1)
diff --git a/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoamUpdateTemplates.C b/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoamUpdateTemplates.C
index 1d2b429467..5f4d78a163 100644
--- a/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoamUpdateTemplates.C
+++ b/applications/utilities/postProcessing/graphics/PVReaders/PVFoamReader/vtkPVFoam/vtkPVFoamUpdateTemplates.C
@@ -45,7 +45,7 @@ void Foam::vtkPVFoam::updateInfoFields
             << endl;
     }
 
-    stringList enabledEntries;
+    HashSet<string> enabledEntries;
     if (!select->GetNumberOfArrays() && !meshPtr_)
     {
         // enable 'p' and 'U' only on the first call
@@ -126,7 +126,7 @@ void Foam::vtkPVFoam::updateInfoFields
     );
 
 
-    // restore the enabled selections
+    // Restore the enabled selections
     setSelectedArrayEntries(select, enabledEntries);
 
     if (debug)
diff --git a/applications/utilities/postProcessing/graphics/PVReaders/PVblockMeshReader/vtkPVblockMesh/vtkPVblockMesh.C b/applications/utilities/postProcessing/graphics/PVReaders/PVblockMeshReader/vtkPVblockMesh/vtkPVblockMesh.C
index 4d85e72982..d5cddbae3b 100644
--- a/applications/utilities/postProcessing/graphics/PVReaders/PVblockMeshReader/vtkPVblockMesh/vtkPVblockMesh.C
+++ b/applications/utilities/postProcessing/graphics/PVReaders/PVblockMeshReader/vtkPVblockMesh/vtkPVblockMesh.C
@@ -303,10 +303,11 @@ void Foam::vtkPVblockMesh::updateInfo()
     vtkDataArraySelection* blockSelection = reader_->GetBlockSelection();
     vtkDataArraySelection* edgeSelection  = reader_->GetCurvedEdgesSelection();
 
-    // preserve the enabled selections if possible
-    stringList enabledParts;
-    stringList enabledEdges;
     const bool firstTime = (!blockSelection->GetNumberOfArrays() && !meshPtr_);
+
+    // Preserve the enabled selections if possible
+    HashSet<string> enabledParts;
+    HashSet<string> enabledEdges;
     if (!firstTime)
     {
         enabledParts = getSelectedArrayEntries(blockSelection);
@@ -326,7 +327,7 @@ void Foam::vtkPVblockMesh::updateInfo()
     // Update curved edges list
     updateInfoEdges(edgeSelection);
 
-    // restore the enabled selections
+    // Restore the enabled selections
     if (!firstTime)
     {
         setSelectedArrayEntries(blockSelection, enabledParts);
diff --git a/applications/utilities/postProcessing/graphics/PVReaders/foamPv/foamPvCore.C b/applications/utilities/postProcessing/graphics/PVReaders/foamPv/foamPvCore.C
index a9a4d1940d..d9c0373460 100644
--- a/applications/utilities/postProcessing/graphics/PVReaders/foamPv/foamPvCore.C
+++ b/applications/utilities/postProcessing/graphics/PVReaders/foamPv/foamPvCore.C
@@ -194,22 +194,22 @@ Foam::hashedWordList Foam::foamPvCore::getSelected
 }
 
 
-Foam::stringList Foam::foamPvCore::getSelectedArrayEntries
+Foam::HashSet<Foam::string>
+Foam::foamPvCore::getSelectedArrayEntries
 (
     vtkDataArraySelection* select
 )
 {
-    stringList selections(select->GetNumberOfArrays());
-    label nElem = 0;
+    const int n = select->GetNumberOfArrays();
+    HashSet<string> selections(2*n);
 
-    forAll(selections, elemI)
+    for (int i=0; i < n; ++i)
     {
-        if (select->GetArraySetting(elemI))
+        if (select->GetArraySetting(i))
         {
-            selections[nElem++] = select->GetArrayName(elemI);
+            selections.insert(select->GetArrayName(i));
         }
     }
-    selections.setSize(nElem);
 
     if (debug > 1)
     {
@@ -221,9 +221,9 @@ Foam::stringList Foam::foamPvCore::getSelectedArrayEntries
         }
         Info<< " )\nselected(";
 
-        forAll(selections, elemI)
+        for (auto k : selections)
         {
-            Info<< " " << selections[elemI];
+            Info<< " " << k;
         }
         Info<< " )\n";
     }
@@ -232,65 +232,61 @@ Foam::stringList Foam::foamPvCore::getSelectedArrayEntries
 }
 
 
-Foam::stringList Foam::foamPvCore::getSelectedArrayEntries
+Foam::HashSet<Foam::string>
+Foam::foamPvCore::getSelectedArrayEntries
 (
     vtkDataArraySelection* select,
-    const arrayRange& selector
+    const arrayRange& slice
 )
 {
-    stringList selections(selector.size());
-    label nElem = 0;
+    const int n = select->GetNumberOfArrays();
+    HashSet<string> enabled(2*n);
 
-    for (auto i : selector)
+    for (auto i : slice)
     {
         if (select->GetArraySetting(i))
         {
-            selections[nElem++] = select->GetArrayName(i);
+            enabled.insert(select->GetArrayName(i));
         }
     }
-    selections.setSize(nElem);
 
     if (debug > 1)
     {
         Info<< "available(";
-        for (auto i : selector)
+        for (auto i : slice)
         {
             Info<< " \"" << select->GetArrayName(i) << "\"";
         }
         Info<< " )\nselected(";
 
-        forAll(selections, elemI)
+        for (auto k : enabled)
         {
-            Info<< " " << selections[elemI];
+            Info<< " " << k;
         }
         Info<< " )\n";
     }
 
-    return selections;
+    return enabled;
 }
 
 
 void Foam::foamPvCore::setSelectedArrayEntries
 (
     vtkDataArraySelection* select,
-    const stringList& selections
+    const HashSet<string>& enabled
 )
 {
     const int n = select->GetNumberOfArrays();
+    // disable everything not explicitly enabled
     select->DisableAllArrays();
 
-    // Loop through entries, setting values from selectedEntries
+    // Loop through entries, enabling as required
     for (int i=0; i < n; ++i)
     {
-        const string arrayName(select->GetArrayName(i));
-
-        forAll(selections, elemI)
+        const char* arrayName = select->GetArrayName(i);
+        if (enabled.found(arrayName))
         {
-            if (selections[elemI] == arrayName)
-            {
-                select->EnableArray(arrayName.c_str());
-                break;
-            }
+            select->EnableArray(arrayName);
         }
     }
 }
diff --git a/applications/utilities/postProcessing/graphics/PVReaders/foamPv/foamPvCore.H b/applications/utilities/postProcessing/graphics/PVReaders/foamPv/foamPvCore.H
index 8a81633408..6243d5343c 100644
--- a/applications/utilities/postProcessing/graphics/PVReaders/foamPv/foamPvCore.H
+++ b/applications/utilities/postProcessing/graphics/PVReaders/foamPv/foamPvCore.H
@@ -39,6 +39,7 @@ SourceFiles
 #include "pointList.H"
 #include "wordList.H"
 #include "Hash.H"
+#include "HashSet.H"
 #include "hashedWordList.H"
 #include "labelRange.H"
 
@@ -208,25 +209,25 @@ public:
     );
 
 
-    //- Retrieve the current selections
-    static stringList getSelectedArrayEntries
+    //- Retrieve the currently enabled selections
+    static HashSet<string> getSelectedArrayEntries
     (
         vtkDataArraySelection* select
     );
 
-    //- Retrieve a sub-list of the current selections
-    static stringList getSelectedArrayEntries
+    //- Retrieve a sub-list of the currently enabled selections
+    static HashSet<string> getSelectedArrayEntries
     (
         vtkDataArraySelection* select,
-        const arrayRange& selector
+        const arrayRange& slice
     );
 
 
-    //- Set selection(s)
+    //- Enable the selection(s)
     static void setSelectedArrayEntries
     (
         vtkDataArraySelection* select,
-        const stringList& selections
+        const HashSet<string>& enabled
     );