diff --git a/src/BRep/BRep_Tool.cxx b/src/BRep/BRep_Tool.cxx
index d4bade16eb..defb2cdcde 100644
--- a/src/BRep/BRep_Tool.cxx
+++ b/src/BRep/BRep_Tool.cxx
@@ -206,6 +206,17 @@ Handle(Geom_Curve)  BRep_Tool::Curve(const TopoDS_Edge& E,
   return C;
 }
 
+//=======================================================================
+//function : IsGeometric
+//purpose  : Returns True if <F> has a surface.
+//=======================================================================
+Standard_Boolean BRep_Tool::IsGeometric (const TopoDS_Face& F)
+{
+  const BRep_TFace* TF = static_cast<const BRep_TFace*>(F.TShape().get());
+  const Handle(Geom_Surface)& S = TF->Surface();
+  return !S.IsNull();
+}
+
 //=======================================================================
 //function : IsGeometric
 //purpose  : Returns True if <E> is a 3d curve or a curve on
diff --git a/src/BRep/BRep_Tool.hxx b/src/BRep/BRep_Tool.hxx
index fa6efbe69d..12c061cde9 100644
--- a/src/BRep/BRep_Tool.hxx
+++ b/src/BRep/BRep_Tool.hxx
@@ -74,6 +74,9 @@ public:
   //! Returns the  NaturalRestriction  flag of the  face.
   Standard_EXPORT static Standard_Boolean NaturalRestriction (const TopoDS_Face& F);
   
+  //! Returns True if <F> has a surface, false otherwise.
+  Standard_EXPORT static Standard_Boolean IsGeometric (const TopoDS_Face& F);
+
   //! Returns True if <E> is a 3d curve or a curve on
   //! surface.
   Standard_EXPORT static Standard_Boolean IsGeometric (const TopoDS_Edge& E);
diff --git a/src/BRepTools/BRepTools.cxx b/src/BRepTools/BRepTools.cxx
index ae2cb9dce4..eb178570de 100644
--- a/src/BRepTools/BRepTools.cxx
+++ b/src/BRepTools/BRepTools.cxx
@@ -62,6 +62,7 @@
 #include <TopoDS_Vertex.hxx>
 #include <TopoDS_Wire.hxx>
 #include <TopTools_SequenceOfShape.hxx>
+#include <TopTools_MapOfShape.hxx>
 #include <GeomLib_CheckCurveOnSurface.hxx>
 #include <errno.h>
 //=======================================================================
@@ -843,19 +844,36 @@ Standard_Boolean BRepTools::Read(TopoDS_Shape& Sh,
 //purpose  : 
 //=======================================================================
 
-void BRepTools::Clean(const TopoDS_Shape& theShape)
+void BRepTools::Clean (const TopoDS_Shape& theShape)
 {
+  if (theShape.IsNull())
+    return;
+
   BRep_Builder aBuilder;
   Handle(Poly_Triangulation) aNullTriangulation;
   Handle(Poly_PolygonOnTriangulation) aNullPoly;
 
-  if (theShape.IsNull())
-    return;
+  TopTools_MapOfShape aShapeMap;
+  const TopLoc_Location anEmptyLoc;
 
   TopExp_Explorer aFaceIt(theShape, TopAbs_FACE);
   for (; aFaceIt.More(); aFaceIt.Next())
   {
-    const TopoDS_Face& aFace = TopoDS::Face(aFaceIt.Current());
+    TopoDS_Shape aFaceNoLoc = aFaceIt.Current();
+    aFaceNoLoc.Location (anEmptyLoc);
+    if (!aShapeMap.Add (aFaceNoLoc))
+    {
+      // the face has already been processed
+      continue;
+    }
+
+    const TopoDS_Face& aFace = TopoDS::Face (aFaceIt.Current());
+    if (!BRep_Tool::IsGeometric (aFace))
+    {
+      // Do not remove triangulation as there is no surface to recompute it.
+      continue;
+    }
+
 
     TopLoc_Location aLoc;
     const Handle(Poly_Triangulation)& aTriangulation =
@@ -865,6 +883,10 @@ void BRepTools::Clean(const TopoDS_Shape& theShape)
       continue;
 
     // Nullify edges
+    // Theoretically, the edges on the face (with surface) may have no geometry
+    // (no curve 3d or 2d or both). Such faces should be considered as invalid and
+    // are not supported by current implementation. So, both triangulation of the face
+    // and polygon on triangulation of the edges are removed unconditionally.
     TopExp_Explorer aEdgeIt(aFace, TopAbs_EDGE);
     for (; aEdgeIt.More(); aEdgeIt.Next())
     {
@@ -874,8 +896,34 @@ void BRepTools::Clean(const TopoDS_Shape& theShape)
 
     aBuilder.UpdateFace(aFace, aNullTriangulation);
   }
-}
 
+  // Iterate over all edges seeking for 3d polygons
+  Handle (Poly_Polygon3D) aNullPoly3d;
+  TopExp_Explorer aEdgeIt (theShape, TopAbs_EDGE);
+  for (; aEdgeIt.More (); aEdgeIt.Next ())
+  {
+    TopoDS_Edge anEdgeNoLoc = TopoDS::Edge (aEdgeIt.Current());
+    anEdgeNoLoc.Location (anEmptyLoc);
+
+    if (!aShapeMap.Add (anEdgeNoLoc))
+    {
+      // the edge has already been processed
+      continue;
+    }
+    if (!BRep_Tool::IsGeometric (TopoDS::Edge (anEdgeNoLoc)))
+    {
+      // Do not remove polygon 3d as there is no curve to recompute it.
+      continue;
+    }
+
+    TopLoc_Location aLoc;
+    Handle (Poly_Polygon3D) aPoly3d = BRep_Tool::Polygon3D (anEdgeNoLoc, aLoc);
+    if (aPoly3d.IsNull())
+      continue;
+
+    aBuilder.UpdateEdge (anEdgeNoLoc, aNullPoly3d);
+  }
+}
 //=======================================================================
 //function : RemoveUnusedPCurves
 //purpose  : 
diff --git a/src/BRepTools/BRepTools.hxx b/src/BRepTools/BRepTools.hxx
index cc49cc1044..74ca6749e2 100644
--- a/src/BRepTools/BRepTools.hxx
+++ b/src/BRepTools/BRepTools.hxx
@@ -152,9 +152,11 @@ public:
   //! same point at there common extremity.
   Standard_EXPORT static void UpdateFaceUVPoints (const TopoDS_Face& F);
   
-  //! Removes all the triangulations of the faces of <S>
-  //! and removes all polygons on triangulations of the
-  //! edges.
+  //! Removes all cashed polygonal representation of the shape,
+  //! i.e. the triangulations of the faces of <S> and polygons on
+  //! triangulations and polygons 3d of the edges.
+  //! In case polygonal representation is the only available representation
+  //! for the shape (shape does not have geometry) it is not removed.
   Standard_EXPORT static void Clean (const TopoDS_Shape& S);
   
   //! Removes all the pcurves of the edges of <S> that