diff --git a/src/BOPAlgo/BOPAlgo_PaveFiller_7.cxx b/src/BOPAlgo/BOPAlgo_PaveFiller_7.cxx
index 1e91f5529a..20175dfd1c 100644
--- a/src/BOPAlgo/BOPAlgo_PaveFiller_7.cxx
+++ b/src/BOPAlgo/BOPAlgo_PaveFiller_7.cxx
@@ -29,6 +29,7 @@
 #include <BOPDS_Interf.hxx>
 #include <BOPDS_Iterator.hxx>
 #include <BOPDS_ListOfPaveBlock.hxx>
+#include <BOPDS_MapOfPair.hxx>
 #include <BOPDS_MapOfPaveBlock.hxx>
 #include <BOPDS_Pave.hxx>
 #include <BOPDS_PaveBlock.hxx>
@@ -246,28 +247,42 @@ class BOPAlgo_MPC : public BOPAlgo_Algo  {
     {
       OCC_CATCH_SIGNALS
 
-      Standard_Integer iErr;
-      //
-      iErr=1;
-      if (!myEz.IsNull()) {
-        TopoDS_Edge aSpz;
-        //
-        BOPTools_AlgoTools::MakeSplitEdge(myEz,myV1, myT1, 
-                                          myV2, myT2, aSpz);
-        //
-        iErr=
-          BOPTools_AlgoTools2D::AttachExistingPCurve(aSpz, 
-                                                     myE, 
-                                                     myF, 
-                                                     myContext);
+      // Check if edge has pcurve. If no then make its copy to avoid data races,
+      // and use it to build pcurve.
+      TopoDS_Edge aCopyE = myE;
+      Standard_Real f, l;
+      Handle(Geom2d_Curve) aC2d = BRep_Tool::CurveOnSurface(aCopyE, myF, f, l);
+      if (aC2d.IsNull())
+      {
+        aCopyE = BOPTools_AlgoTools::CopyEdge(aCopyE);
+
+        Standard_Integer iErr = 1;
+        if (!myEz.IsNull())
+        {
+          // Attach pcurve from the original edge
+          TopoDS_Edge aSpz;
+          BOPTools_AlgoTools::MakeSplitEdge(myEz, myV1, myT1,
+                                            myV2, myT2, aSpz);
+          iErr = BOPTools_AlgoTools2D::AttachExistingPCurve(aSpz,
+                                                            aCopyE, 
+                                                            myF,
+                                                            myContext);
+        }
+        if (iErr)
+          BOPTools_AlgoTools2D::BuildPCurveForEdgeOnFace(aCopyE, myF, myContext);
+
+        myNewC2d = BRep_Tool::CurveOnSurface(aCopyE, myF, f, l);
+        if (myNewC2d.IsNull())
+        {
+          AddError(new BOPAlgo_AlertBuildingPCurveFailed(TopoDS_Shape()));
+          return;
+        }
+        else
+          myNewTol = BRep_Tool::Tolerance(aCopyE);
       }
-      //
-      if (iErr) { 
-        BOPTools_AlgoTools2D::BuildPCurveForEdgeOnFace(myE, myF, myContext);
-      }
-      // 
+
       if (myFlag) {
-        UpdateVertices(myE, myF);
+        UpdateVertices(aCopyE, myF);
       }
     }
     catch (Standard_Failure)
@@ -275,7 +290,17 @@ class BOPAlgo_MPC : public BOPAlgo_Algo  {
       AddError(new BOPAlgo_AlertBuildingPCurveFailed(TopoDS_Shape()));
     }
   }
-  //
+
+  const Handle(Geom2d_Curve)& GetNewPCurve() const
+  {
+    return myNewC2d;
+  }
+
+  Standard_Real GetNewTolerance() const
+  {
+    return myNewTol;
+  }
+
  protected:
   Standard_Boolean myFlag;
   TopoDS_Edge myE;
@@ -285,6 +310,8 @@ class BOPAlgo_MPC : public BOPAlgo_Algo  {
   Standard_Real myT1;
   TopoDS_Vertex myV2;
   Standard_Real myT2;
+  Handle(Geom2d_Curve) myNewC2d;
+  Standard_Real myNewTol;
   //
   Handle(IntTools_Context) myContext;
 };
@@ -541,7 +568,7 @@ void BOPAlgo_PaveFiller::MakePCurves()
       (!mySectionAttribute.PCurveOnS1() && !mySectionAttribute.PCurveOnS2()))
     return;
   Standard_Boolean bHasPC;
-  Standard_Integer i, nF1, nF2, aNbC, k, nE, aNbFF, aNbFI, nEx;
+  Standard_Integer i, nF1, aNbC, k, nE, aNbFF, aNbFI, nEx;
   Standard_Integer j, aNbPBIn, aNbPBOn;
   BOPDS_ListIteratorOfListOfPaveBlock aItLPB;
   TopoDS_Face aF1F, aF2F;
@@ -637,44 +664,52 @@ void BOPAlgo_PaveFiller::MakePCurves()
     }
   }// for (i=0; i<aNbFI; ++i) {
   //
-  // 2. Process section edges
+  // 2. Process section edges. P-curves on them must already be computed.
+  // However, we must provide the call to UpdateVertices.
   Standard_Boolean bPCurveOnS[2];
-  Standard_Integer m;
-  TopoDS_Face aFf[2];
-  //
   bPCurveOnS[0]=mySectionAttribute.PCurveOnS1();
   bPCurveOnS[1]=mySectionAttribute.PCurveOnS2();
   //
   if (bPCurveOnS[0] || bPCurveOnS[1]) {
+    // container to remember already added edge-face pairs
+    BOPDS_MapOfPair anEFPairs;
     BOPDS_VectorOfInterfFF& aFFs=myDS->InterfFF();
     aNbFF=aFFs.Extent();
     for (i=0; i<aNbFF; ++i) {
       const BOPDS_InterfFF& aFF=aFFs(i);
-      aFF.Indices(nF1, nF2);
+      const BOPDS_VectorOfCurve& aVNC = aFF.Curves();
+      aNbC = aVNC.Extent();
+      if (aNbC == 0)
+        continue;
+      Standard_Integer nF[2];
+      aFF.Indices(nF[0], nF[1]);
       //
-      aFf[0]=(*(TopoDS_Face *)(&myDS->Shape(nF1)));
+      TopoDS_Face aFf[2];
+      aFf[0] = (*(TopoDS_Face *)(&myDS->Shape(nF[0])));
       aFf[0].Orientation(TopAbs_FORWARD);
       //
-      aFf[1]=(*(TopoDS_Face *)(&myDS->Shape(nF2)));
+      aFf[1]=(*(TopoDS_Face *)(&myDS->Shape(nF[1])));
       aFf[1].Orientation(TopAbs_FORWARD);
       //
-      const BOPDS_VectorOfCurve& aVNC=aFF.Curves();
-      aNbC=aVNC.Extent();
-      for (k=0; k<aNbC; ++k) {
+      for (k=0; k<aNbC; ++k)
+      {
         const BOPDS_Curve& aNC=aVNC(k);
         const BOPDS_ListOfPaveBlock& aLPB=aNC.PaveBlocks();
         aItLPB.Initialize(aLPB);
-        for(; aItLPB.More(); aItLPB.Next()) {
+        for(; aItLPB.More(); aItLPB.Next())
+        {
           const Handle(BOPDS_PaveBlock)& aPB=aItLPB.Value();
           nE=aPB->Edge();
           const TopoDS_Edge& aE=(*(TopoDS_Edge *)(&myDS->Shape(nE))); 
           //
-          for (m=0; m<2; ++m) {
-            if (bPCurveOnS[m]) {
-              BOPAlgo_MPC& aMPC=aVMPC.Append1();
+          for (Standard_Integer m = 0; m<2; ++m)
+          {
+            if (bPCurveOnS[m] && anEFPairs.Add(BOPDS_Pair(nE, nF[m])))
+            {
+              BOPAlgo_MPC& aMPC = aVMPC.Append1();
               aMPC.SetEdge(aE);
               aMPC.SetFace(aFf[m]);
-              aMPC.SetFlag(bPCurveOnS[m]);
+              aMPC.SetFlag(Standard_True);
               aMPC.SetProgressIndicator(myProgressIndicator);
             }
           }
@@ -687,18 +722,27 @@ void BOPAlgo_PaveFiller::MakePCurves()
   BOPAlgo_MPCCnt::Perform(myRunParallel, aVMPC, myContext);
   //======================================================
 
-  // Add warnings of the failed projections
+  // Add warnings of the failed projections and update edges with new pcurves
   Standard_Integer aNb = aVMPC.Extent();
   for (i = 0; i < aNb; ++i)
   {
-    if (aVMPC(i).HasErrors())
+    const BOPAlgo_MPC& aMPC = aVMPC(i);
+    if (aMPC.HasErrors())
     {
       TopoDS_Compound aWC;
       BRep_Builder().MakeCompound(aWC);
-      BRep_Builder().Add(aWC, aVMPC(i).Edge());
-      BRep_Builder().Add(aWC, aVMPC(i).Face());
+      BRep_Builder().Add(aWC, aMPC.Edge());
+      BRep_Builder().Add(aWC, aMPC.Face());
       AddWarning(new BOPAlgo_AlertBuildingPCurveFailed(aWC));
     }
+    else
+    {
+      const Handle(Geom2d_Curve)& aNewPC = aMPC.GetNewPCurve();
+      // if aNewPC is null we do not need to update the edge because it already contains
+      // valid p-curve, and only vertices have been updated.
+      if (!aNewPC.IsNull())
+        BRep_Builder().UpdateEdge(aMPC.Edge(), aNewPC, aMPC.Face(), aMPC.GetNewTolerance());
+    }
   }
 }
 //=======================================================================
diff --git a/src/BOPTools/BOPTools_AlgoTools.hxx b/src/BOPTools/BOPTools_AlgoTools.hxx
index dddfb07ae2..4adb7ada67 100644
--- a/src/BOPTools/BOPTools_AlgoTools.hxx
+++ b/src/BOPTools/BOPTools_AlgoTools.hxx
@@ -248,7 +248,9 @@ public:
 
   //! Compute a 3D-point on the edge <aEdge> at parameter <aPrm>
   Standard_EXPORT static void PointOnEdge (const TopoDS_Edge& aEdge, const Standard_Real aPrm, gp_Pnt& aP);
-  
+
+  //! Makes a copy of <theEdge> with vertices.
+  Standard_EXPORT static TopoDS_Edge CopyEdge(const TopoDS_Edge& theEdge);
 
   //! Make the edge from base edge <aE1> and two vertices <aV1,aV2>
   //! at parameters <aP1,aP2>
diff --git a/src/BOPTools/BOPTools_AlgoTools_2.cxx b/src/BOPTools/BOPTools_AlgoTools_2.cxx
index d78965c85e..90baa8a9f6 100644
--- a/src/BOPTools/BOPTools_AlgoTools_2.cxx
+++ b/src/BOPTools/BOPTools_AlgoTools_2.cxx
@@ -132,6 +132,20 @@ void BOPTools_AlgoTools::MakeSectEdge(const IntTools_Curve& aIC,
   
 }
 
+//=======================================================================
+// function: CopyEdge
+// purpose: 
+//=======================================================================
+TopoDS_Edge BOPTools_AlgoTools::CopyEdge(const TopoDS_Edge& theEdge)
+{
+  TopoDS_Edge aNewEdge = TopoDS::Edge(theEdge.Oriented(TopAbs_FORWARD));
+  aNewEdge.EmptyCopy();
+  for (TopoDS_Iterator it(theEdge, Standard_False); it.More(); it.Next())
+    BRep_Builder().Add(aNewEdge, it.Value());
+  aNewEdge.Orientation(theEdge.Orientation());
+  return aNewEdge;
+}
+
 //=======================================================================
 // function: MakeSplitEdge
 // purpose: 
@@ -143,9 +157,6 @@ void BOPTools_AlgoTools::MakeSplitEdge(const TopoDS_Edge&   aE,
                                        const Standard_Real  aP2,
                                        TopoDS_Edge& aNewEdge)
 {
-  Standard_Real aTol;//f, l, 
-  aTol=BRep_Tool::Tolerance(aE);
-  //
   TopoDS_Edge E = TopoDS::Edge(aE.Oriented(TopAbs_FORWARD));
   E.EmptyCopy();
   //
@@ -157,7 +168,6 @@ void BOPTools_AlgoTools::MakeSplitEdge(const TopoDS_Edge&   aE,
     BB.Add  (E, aV2);
   }
   BB.Range(E, aP1, aP2);
-  BB.UpdateEdge(E, aTol);
   aNewEdge=E;
   aNewEdge.Orientation(aE.Orientation());
 }
diff --git a/tests/bugs/modalg_7/bug28200 b/tests/bugs/modalg_7/bug28200
index 6a043ebf0b..4d517fb3d4 100644
--- a/tests/bugs/modalg_7/bug28200
+++ b/tests/bugs/modalg_7/bug28200
@@ -33,7 +33,7 @@ donly result
 fit
 checkview -screenshot -2d -path ${imagedir}/${test_image}_1.png
 
-left
+smallview -Y+Z
 fit
 checkview -screenshot -2d -path ${imagedir}/${test_image}_2.png
 
diff --git a/tests/bugs/modalg_7/bug29182 b/tests/bugs/modalg_7/bug29182
new file mode 100644
index 0000000000..15b30d7c1e
--- /dev/null
+++ b/tests/bugs/modalg_7/bug29182
@@ -0,0 +1,24 @@
+puts "========"
+puts "OCC29182"
+puts "========"
+puts ""
+#################################################
+# BOPAlgo_PaveFiller sometimes raises exception in parallel mode
+#################################################
+
+binrestore [locate_data_file bug29182_access_violation.bin] a
+explode a So
+bclearobjects
+bcleartools
+baddobjects a_1
+baddtools a_2 a_3 a_4 a_5 a_6 a_7 a_8 a_9 a_10 a_11 a_12
+brunparallel 1
+bfillds
+bbuild result
+
+checknbshapes result -m result -shell 17 -solid 17
+checkprops result -v 1.18596e+006 -s 1.28028e+006
+checkshape result
+if ![regexp "This shape seems to be OK" [bopcheck result]] {
+  puts "Error: result is self-intersected"
+}
diff --git a/tests/bugs/modalg_7/bug29182_1 b/tests/bugs/modalg_7/bug29182_1
new file mode 100644
index 0000000000..e9433f6749
--- /dev/null
+++ b/tests/bugs/modalg_7/bug29182_1
@@ -0,0 +1,41 @@
+puts "========"
+puts "OCC29182"
+puts "========"
+puts ""
+#################################################
+# BOPAlgo_PaveFiller sometimes raises exception in parallel mode
+#################################################
+
+# This is synthetic case reproducing the bug.
+# Make a set of cylindrical surface patches intersecting in the same
+# 3d line and run bfillds on them repeatedly 100 times.
+
+cylinder c 0 10 0 1 0 0 10
+mkface fc c pi/3 2*pi/3 -10 10
+
+shape a C
+add fc a
+don a
+
+for {set i 1} {$i <= 10} {incr i} {
+  copy fc f1
+  trotate f1 0 0 0 1 0 0 $i*5
+  add f1 a
+}
+
+brunparallel 1
+bclearobjects
+bcleartools
+baddcompound a
+
+for {set i 1} {$i <= 100} {incr i} {
+  puts "pass $i"
+  set info [string trim [bfillds]]
+  if {$info != "" && [regexp "2D curve" $info]} {
+    break
+  }
+}
+
+if {$i <= 100} {
+  puts "Error: the bug with failure building 2D curve of edge on face is reproduced"
+}