diff --git a/src/IntPatch/IntPatch_ImpImpIntersection_5.gxx b/src/IntPatch/IntPatch_ImpImpIntersection_5.gxx
index 5b54378f8c..df59aea0fd 100644
--- a/src/IntPatch/IntPatch_ImpImpIntersection_5.gxx
+++ b/src/IntPatch/IntPatch_ImpImpIntersection_5.gxx
@@ -601,26 +601,47 @@ Standard_Boolean IntCoSp(const IntSurf_Quadric& Quad1,
 
       gp_Circ cirsol = inter.Circle(1);
       param = ElCLib::LineParameter(Co.Axis(),
-				    cirsol.Location());
-      if (param >= paramapex) {
-	
-	ElCLib::D1(0.,cirsol,ptref,Tgt);
-	Standard_Real qwe = Tgt.DotCross(Quad2.Normale(ptref),
-					 Quad1.Normale(ptref));
-	if(qwe> 0.000000001) {
-	  trans1 = IntSurf_Out;
-	  trans2 = IntSurf_In;
-	}
-	else if(qwe< -0.000000001){
-	  trans1 = IntSurf_In;
-	  trans2 = IntSurf_Out;
-	}
-	else { 
-	  trans1=trans2=IntSurf_Undecided;
-	}
-	Handle(IntPatch_GLine) glig = new IntPatch_GLine(cirsol,Standard_False,trans1,trans2);
-	slin.Append(glig);
+                                    cirsol.Location());
+      ElCLib::D1(0., cirsol, ptref, Tgt);
+      Standard_Real qwe = Tgt.DotCross(Quad2.Normale(ptref),
+                                       Quad1.Normale(ptref));
+
+      if (param >= paramapex)
+      {
+        if (qwe > Precision::PConfusion())
+        {
+          trans1 = IntSurf_Out;
+          trans2 = IntSurf_In;
+        }
+        else if (qwe < -Precision::PConfusion())
+        {
+          trans1 = IntSurf_In;
+          trans2 = IntSurf_Out;
+        }
+        else
+        {
+          trans1 = trans2 = IntSurf_Undecided;
+        }
       }
+      else
+      {
+        if (qwe < -Precision::PConfusion())
+        {
+          trans1 = IntSurf_Out;
+          trans2 = IntSurf_In;
+        }
+        else if (qwe > Precision::PConfusion())
+        {
+          trans1 = IntSurf_In;
+          trans2 = IntSurf_Out;
+        }
+        else
+        {
+          trans1 = trans2 = IntSurf_Undecided;
+        }
+      }
+      Handle(IntPatch_GLine) glig = new IntPatch_GLine(cirsol, Standard_False, trans1, trans2);
+      slin.Append(glig);
     }
     break;
 
diff --git a/tests/lowalgos/intss/begin b/tests/lowalgos/intss/begin
index b9d05984d3..b6734b105d 100644
--- a/tests/lowalgos/intss/begin
+++ b/tests/lowalgos/intss/begin
@@ -28,3 +28,23 @@ proc CheckLoops {theCurve theCosMaxAngle {theNbPoints 1000.0}} {
     dset dz1 dz2
   }
 }
+
+# General check of the result of geometrical intersection
+help CheckIntersectionResult { surf1 surf2 ListOfCurves NbPoints TolerS1 TolerS2 }
+proc CheckIntersectionResult {theSurf1 theSurf2 theListOfCurves theNbPoints theTolerS1 theTolerS2} {
+  upvar #0 $theSurf1 s1
+  upvar #0 $theSurf2 s2
+
+  foreach a $theListOfCurves {
+    puts "** Check of $a **"
+    upvar #0 $a aCurve
+    bounds aCurve U1 U2
+    
+    if {[dval U2-U1] < 1.0e-9} {
+      puts "Error: Wrong range of $a"
+    }
+    
+    xdistcs aCurve s1 U1 U2 $theNbPoints $theTolerS1
+    xdistcs aCurve s2 U1 U2 $theNbPoints $theTolerS2
+  }
+}
\ No newline at end of file
diff --git a/tests/lowalgos/intss/bug21494 b/tests/lowalgos/intss/bug21494
deleted file mode 100644
index f91ce163eb..0000000000
--- a/tests/lowalgos/intss/bug21494
+++ /dev/null
@@ -1,22 +0,0 @@
-puts "TODO OCC21494 ALL: Error: Intersection between cone and sphere fails"
-
-puts "========"
-puts "OCC21494"
-puts "========"
-puts ""
-############################################
-# Intersection between cone and sphere fails
-############################################
-
-pcone c 15 0 10
-psphere s 10
-explode c f
-explode s f
-mksurface sc c_1
-mksurface ss s_1
-
-intersect i sc ss
-
-if { [info exist i_1] == 0 } {
-  puts "Error: Intersection between cone and sphere fails"
-}
diff --git a/tests/lowalgos/intss/bug21494_1 b/tests/lowalgos/intss/bug21494_1
new file mode 100644
index 0000000000..81f80ad557
--- /dev/null
+++ b/tests/lowalgos/intss/bug21494_1
@@ -0,0 +1,32 @@
+puts "========"
+puts "OCC21494: Intersection between cone and sphere fails"
+puts "========"
+puts ""
+
+pcone bc 15 0 10
+psphere bs 10
+explode bc f
+explode bs f
+
+set log [bopcurves bc_1 bs_1 -2d]
+
+regexp {Tolerance Reached=+([-0-9.+eE]+)\n+([-0-9.+eE]+)} $log full Toler NbCurv
+
+if { ![regexp {1 point\(s\) found} $log full] } {
+  puts "Error: Cone apex and Pole of sphere are excluded from the intersection result"
+}
+
+if {$NbCurv != 1} {
+  puts "Error: Please check NbCurves for intersector"
+}
+
+if { $Toler > 2.0e-7} {
+  puts "Error: Big tolerance value"  
+}
+
+smallview
+don c_* p_*
+fit
+disp bc bs
+
+checkview -screenshot -2d -path ${imagedir}/${test_image}_3d.png
diff --git a/tests/lowalgos/intss/bug21494_2 b/tests/lowalgos/intss/bug21494_2
new file mode 100644
index 0000000000..d13d7126c5
--- /dev/null
+++ b/tests/lowalgos/intss/bug21494_2
@@ -0,0 +1,78 @@
+puts "========"
+puts "OCC21494"
+puts "========"
+puts ""
+############################################
+# Intersection between cone and sphere fails
+############################################
+
+foreach a [directory res*] {unset $a}
+
+set aGoodNbCurves 1
+
+pcone c 15 0 10
+psphere s 10
+explode c f
+explode s f
+mksurface sc c_1
+mksurface ss s_1
+
+intersect res sc ss
+
+if { ![info exist res_p_1] } {
+  puts "Error: Cone apex and Pole of sphere are excluded from the intersection result"
+}
+
+set che [whatis res]
+set ind [string first "3d curve" $che]
+if {${ind} >= 0} {
+  #Only variable "res" exists
+  renamevar res res_1
+}
+
+bclearobjects
+bcleartools
+
+set CurvesList {}
+
+set ic 1
+set AllowRepeat 1
+while { $AllowRepeat != 0 } {
+  set che [whatis res_$ic]
+  set ind [string first "3d curve" $che]
+  if {${ind} < 0} {
+    set AllowRepeat 0
+  } else {
+    lappend CurvesList res_$ic
+    mkedge ee res_$ic
+    baddobjects ee
+    incr ic
+  }
+}
+
+set ic [expr $ic - 1]
+
+if { $ic != $aGoodNbCurves } {
+  puts "Error: $aGoodNbCurves curves is expected but $ic ones are found"
+} else {
+  CheckIntersectionResult sc ss $CurvesList 100 2.0e-7 2.0e-7
+  
+  if {$ic > 1} {
+    bfillds
+    bbuild result    
+  } elseif {$ic > 0} {
+    mkedge result res_1
+  }
+  
+  # Check gaps between intersection curves
+  checksection result -r 0
+  checkmaxtol result -min_tol 2.0e-7
+
+  checknbshapes result -edge 1 -vertex 1
+}
+
+smallview
+don result*
+fit
+
+checkview -screenshot -2d -path ${imagedir}/${test_image}.png