diff --git a/src/phasicFlow/structuredData/boundaries/boundaryBase/boundaryBase.hpp b/src/phasicFlow/structuredData/boundaries/boundaryBase/boundaryBase.hpp
index 978f674b..b1f8008a 100644
--- a/src/phasicFlow/structuredData/boundaries/boundaryBase/boundaryBase.hpp
+++ b/src/phasicFlow/structuredData/boundaries/boundaryBase/boundaryBase.hpp
@@ -339,7 +339,7 @@ public:
 	
 
 	virtual 
-    bool beforeIteration(uint32 iterNum, real t, real dt) = 0 ;
+    bool beforeIteration(uint32 step, uint32 iterNum, real t, real dt) = 0 ;
 
 	virtual 
     bool iterate(uint32 iterNum, real t, real dt) = 0;
diff --git a/src/phasicFlow/structuredData/boundaries/boundaryExit/boundaryExit.cpp b/src/phasicFlow/structuredData/boundaries/boundaryExit/boundaryExit.cpp
index 9937433c..0f530418 100644
--- a/src/phasicFlow/structuredData/boundaries/boundaryExit/boundaryExit.cpp
+++ b/src/phasicFlow/structuredData/boundaries/boundaryExit/boundaryExit.cpp
@@ -42,12 +42,13 @@ pFlow::boundaryExit::boundaryExit
 
 bool pFlow::boundaryExit::beforeIteration
 (
+	uint32 step,
 	uint32 iterNum, 
 	real t,
 	real dt
 )
 {
-
+	if(step!= 2 )return true;
 	if( !boundaryListUpdate(iterNum))return true;
 
 	// nothing have to be done
diff --git a/src/phasicFlow/structuredData/boundaries/boundaryExit/boundaryExit.hpp b/src/phasicFlow/structuredData/boundaries/boundaryExit/boundaryExit.hpp
index f8aa61c5..b4763e26 100644
--- a/src/phasicFlow/structuredData/boundaries/boundaryExit/boundaryExit.hpp
+++ b/src/phasicFlow/structuredData/boundaries/boundaryExit/boundaryExit.hpp
@@ -63,7 +63,7 @@ public:
 		dictionary
 	);
 
-	bool beforeIteration(uint32 iterNum, real t, real dt) override;
+	bool beforeIteration(uint32 step, uint32 iterNum, real t, real dt) override;
 
 	bool iterate(uint32 iterNum, real t, real dt) override;
 
diff --git a/src/phasicFlow/structuredData/boundaries/boundaryList.cpp b/src/phasicFlow/structuredData/boundaries/boundaryList.cpp
index 0e5ddfed..707e00ea 100644
--- a/src/phasicFlow/structuredData/boundaries/boundaryList.cpp
+++ b/src/phasicFlow/structuredData/boundaries/boundaryList.cpp
@@ -172,7 +172,17 @@ pFlow::boundaryList::beforeIteration(uint32 iter, real t, real dt, bool force)
 	
 	for (auto bdry : *this)
 	{
-		if (!bdry->beforeIteration(iter, t, dt))
+		if (!bdry->beforeIteration(1, iter, t, dt))
+		{
+			fatalErrorInFunction << "Error in beforeIteration in boundary "
+			                     << bdry->name() << endl;
+			return false;
+		}
+	}
+
+	for (auto bdry : *this)
+	{
+		if (!bdry->beforeIteration(2, iter, t, dt))
 		{
 			fatalErrorInFunction << "Error in beforeIteration in boundary "
 			                     << bdry->name() << endl;
diff --git a/src/phasicFlow/structuredData/boundaries/boundaryNone/boundaryNone.cpp b/src/phasicFlow/structuredData/boundaries/boundaryNone/boundaryNone.cpp
index 327330dd..7f228562 100644
--- a/src/phasicFlow/structuredData/boundaries/boundaryNone/boundaryNone.cpp
+++ b/src/phasicFlow/structuredData/boundaries/boundaryNone/boundaryNone.cpp
@@ -34,6 +34,7 @@ pFlow::boundaryNone::boundaryNone
 
 bool pFlow::boundaryNone::beforeIteration
 (
+	uint32 step,
 	uint32 iterNum, 
 	real t,
 	real dt
diff --git a/src/phasicFlow/structuredData/boundaries/boundaryNone/boundaryNone.hpp b/src/phasicFlow/structuredData/boundaries/boundaryNone/boundaryNone.hpp
index 8e103d39..68ddf33f 100644
--- a/src/phasicFlow/structuredData/boundaries/boundaryNone/boundaryNone.hpp
+++ b/src/phasicFlow/structuredData/boundaries/boundaryNone/boundaryNone.hpp
@@ -52,7 +52,7 @@ public:
 		dictionary
 	);
 
-	bool beforeIteration(uint32 iterNum, real t, real dt) final;
+	bool beforeIteration(uint32 step, uint32 iterNum, real t, real dt) final;
 
 	bool iterate(uint32 iterNum, real t, real dt) final;
 
diff --git a/src/phasicFlow/structuredData/boundaries/boundaryPeriodic/boundaryPeriodic.cpp b/src/phasicFlow/structuredData/boundaries/boundaryPeriodic/boundaryPeriodic.cpp
index cbdecf71..cf111eb5 100644
--- a/src/phasicFlow/structuredData/boundaries/boundaryPeriodic/boundaryPeriodic.cpp
+++ b/src/phasicFlow/structuredData/boundaries/boundaryPeriodic/boundaryPeriodic.cpp
@@ -51,10 +51,12 @@ pFlow::realx3 pFlow::boundaryPeriodic::boundaryExtensionLength() const
 
 
 bool pFlow::boundaryPeriodic::beforeIteration(
+	uint32 step,
     uint32 iterNum,
     real t,
     real dt)
 {
+	if(step!=2)return true;
 	// nothing have to be done
 	if(empty())
 	{
diff --git a/src/phasicFlow/structuredData/boundaries/boundaryPeriodic/boundaryPeriodic.hpp b/src/phasicFlow/structuredData/boundaries/boundaryPeriodic/boundaryPeriodic.hpp
index 88983fa3..69b0413a 100644
--- a/src/phasicFlow/structuredData/boundaries/boundaryPeriodic/boundaryPeriodic.hpp
+++ b/src/phasicFlow/structuredData/boundaries/boundaryPeriodic/boundaryPeriodic.hpp
@@ -64,7 +64,7 @@ public:
 
 	//const plane& boundaryPlane()const override;*/
 
-	bool beforeIteration(uint32 iterNum, real t, real dt) override;
+	bool beforeIteration(uint32 step, uint32 iterNum, real t, real dt) override;
 
 	bool iterate(uint32 iterNum, real t, real dt) override;
 
diff --git a/src/phasicFlow/structuredData/boundaries/boundaryReflective/boundaryReflective.cpp b/src/phasicFlow/structuredData/boundaries/boundaryReflective/boundaryReflective.cpp
index 74ee4d75..8de9b74f 100644
--- a/src/phasicFlow/structuredData/boundaries/boundaryReflective/boundaryReflective.cpp
+++ b/src/phasicFlow/structuredData/boundaries/boundaryReflective/boundaryReflective.cpp
@@ -46,6 +46,7 @@ pFlow::boundaryReflective::boundaryReflective
 }
 
 bool pFlow::boundaryReflective::beforeIteration(
+    uint32 step,
     uint32 iterNum,
     real t,
     real dt)
diff --git a/src/phasicFlow/structuredData/boundaries/boundaryReflective/boundaryReflective.hpp b/src/phasicFlow/structuredData/boundaries/boundaryReflective/boundaryReflective.hpp
index 43e1ce13..3f3bc64c 100644
--- a/src/phasicFlow/structuredData/boundaries/boundaryReflective/boundaryReflective.hpp
+++ b/src/phasicFlow/structuredData/boundaries/boundaryReflective/boundaryReflective.hpp
@@ -59,7 +59,7 @@ public:
 		dictionary
 	);
 
-	bool beforeIteration(uint32 iterNum, real t, real dt) override;
+	bool beforeIteration(uint32 step, uint32 iterNum, real t, real dt) override;
 
 	bool iterate(uint32 iterNum, real t, real dt) override;