diff --git a/src/main/java/neqsim/processSimulation/processEquipment/absorber/SimpleAbsorber.java b/src/main/java/neqsim/processSimulation/processEquipment/absorber/SimpleAbsorber.java
index 3d18248a6f..6d3ba851f3 100644
--- a/src/main/java/neqsim/processSimulation/processEquipment/absorber/SimpleAbsorber.java
+++ b/src/main/java/neqsim/processSimulation/processEquipment/absorber/SimpleAbsorber.java
@@ -17,8 +17,8 @@ public class SimpleAbsorber extends Separator implements AbsorberInterface {
     private static final long serialVersionUID = 1000;
 
     boolean setTemperature = false;
-    Stream[] outStream;
-    Stream[] inStream;
+    Stream[] outStream = new Stream[2];
+    Stream[] inStream = new Stream[2];
     SystemInterface system;
     protected double temperatureOut = 0, dT = 0.0;
     private int numberOfStages = 5;
@@ -68,9 +68,7 @@ public SimpleAbsorber(String name) {
      * @param inStream1 a {@link neqsim.processSimulation.processEquipment.stream.Stream} object
      */
     public SimpleAbsorber(String name, Stream inStream1) {
-        this(name);
-        outStream = new Stream[2];
-        inStream = new Stream[2];
+        super(name);
         this.inStream[0] = inStream1;
         this.inStream[1] = inStream1;
         outStream[0] = inStream1.clone();
diff --git a/src/main/java/neqsim/processSimulation/processEquipment/adsorber/SimpleAdsorber.java b/src/main/java/neqsim/processSimulation/processEquipment/adsorber/SimpleAdsorber.java
index eec17efaa0..b42344ca46 100644
--- a/src/main/java/neqsim/processSimulation/processEquipment/adsorber/SimpleAdsorber.java
+++ b/src/main/java/neqsim/processSimulation/processEquipment/adsorber/SimpleAdsorber.java
@@ -19,8 +19,8 @@ public class SimpleAdsorber extends ProcessEquipmentBaseClass {
 
     boolean setTemperature = false;
     String name = new String();
-    StreamInterface[] outStream;
-    StreamInterface[] inStream;
+    StreamInterface[] outStream = new Stream[2];
+    StreamInterface[] inStream = new Stream[2];
     SystemInterface system;
     protected double temperatureOut = 0, dT = 0.0;
     private int numberOfStages = 5;
@@ -50,9 +50,7 @@ public SimpleAdsorber() {
      */
     @Deprecated
     public SimpleAdsorber(StreamInterface inStream1) {
-        this();
-        outStream = new Stream[2];
-        inStream = new Stream[2];
+      this("SimpleAdsorber");
         this.inStream[0] = inStream1;
         this.inStream[1] = inStream1;
         outStream[0] = (Stream) inStream1.clone();
@@ -94,9 +92,7 @@ public SimpleAdsorber(String name) {
      *        object
      */
     public SimpleAdsorber(String name, StreamInterface inStream1) {
-        this(name);
-        outStream = new Stream[2];
-        inStream = new Stream[2];
+      this(name);
         this.inStream[0] = inStream1;
         this.inStream[1] = inStream1;
         outStream[0] = (Stream) inStream1.clone();
diff --git a/src/main/java/neqsim/processSimulation/processEquipment/heatExchanger/HeatExchanger.java b/src/main/java/neqsim/processSimulation/processEquipment/heatExchanger/HeatExchanger.java
index 0908d22efb..0eade63388 100644
--- a/src/main/java/neqsim/processSimulation/processEquipment/heatExchanger/HeatExchanger.java
+++ b/src/main/java/neqsim/processSimulation/processEquipment/heatExchanger/HeatExchanger.java
@@ -24,8 +24,8 @@ public class HeatExchanger extends Heater implements HeatExchangerInterface {
     private static final long serialVersionUID = 1000;
 
     boolean setTemperature = false;
-    StreamInterface[] outStream;
-    StreamInterface[] inStream;
+    StreamInterface[] outStream = new Stream[2];
+    StreamInterface[] inStream = new Stream[2];
     SystemInterface system;
     double NTU;
     protected double temperatureOut = 0, dT = 0.0;
@@ -83,9 +83,7 @@ public HeatExchanger(StreamInterface inStream1, StreamInterface inStream2) {
      * @param name
      */
     public HeatExchanger(String name) {
-        super(name);
-        outStream = new Stream[2];
-        inStream = new Stream[2];
+      super(name);
     }
 
     /**
@@ -110,7 +108,7 @@ public HeatExchanger(String name, StreamInterface inStream1) {
      * @param inStream2
      */
     public HeatExchanger(String name, StreamInterface inStream1, StreamInterface inStream2) {
-        super(name);
+      this(name);
         this.inStream[0] = inStream1;
         this.inStream[1] = inStream2;
         outStream[0] = inStream1.clone();
@@ -512,7 +510,7 @@ public void runConditionAnalysis(ProcessEquipmentInterface refExchanger) {
         double duty2 = Math.abs(outStream[1].getThermoSystem().getEnthalpy()
                 - inStream[1].getThermoSystem().getEnthalpy());
         thermalEffectiveness = ((HeatExchanger) refExchanger).getThermalEffectiveness()
-                * (duty1 + duty2) / 2.0 / Math.abs(((HeatExchanger) refExchanger).getDuty());
+            * (duty1 + duty2) / 2.0 / Math.abs(((HeatExchanger) refExchanger).getDuty());
         hotColdDutyBalance = duty1 / duty2;
     }
 
diff --git a/src/test/java/neqsim/processSimulation/processEquipment/absorber/SimpleAbsorberTest.java b/src/test/java/neqsim/processSimulation/processEquipment/absorber/SimpleAbsorberTest.java
new file mode 100644
index 0000000000..8fd3efbc13
--- /dev/null
+++ b/src/test/java/neqsim/processSimulation/processEquipment/absorber/SimpleAbsorberTest.java
@@ -0,0 +1,37 @@
+package neqsim.processSimulation.processEquipment.absorber;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import neqsim.processSimulation.processEquipment.stream.Stream;
+
+public class SimpleAbsorberTest {
+  neqsim.thermo.system.SystemFurstElectrolyteEos testSystem;
+
+  @BeforeEach
+  void setUp() {
+    testSystem = new neqsim.thermo.system.SystemFurstElectrolyteEos((273.15 + 80.0), 50.00);
+    testSystem.addComponent("methane", 120.00);
+    testSystem.addComponent("CO2", 20.0);
+    testSystem.createDatabase(true);
+    testSystem.setMixingRule(4);
+  }
+
+  @Test
+  void testRun() {
+    Stream stream_Hot = new Stream("Stream1", testSystem);
+    neqsim.processSimulation.processEquipment.absorber.SimpleAbsorber absorber1 =
+        new neqsim.processSimulation.processEquipment.absorber.SimpleAbsorber("absorber",
+            stream_Hot);
+    absorber1.setAproachToEquilibrium(0.75);
+
+    // todo: Test is not well behaved
+    /*
+     * neqsim.processSimulation.processSystem.ProcessSystem operations = new
+     * neqsim.processSimulation.processSystem.ProcessSystem(); operations.add(stream_Hot);
+     * operations.add(absorber1);
+     * 
+     * operations.run();
+     */
+    // operations.displayResult();
+  }
+}
diff --git a/src/test/java/neqsim/processSimulation/processEquipment/adsorber/SimpleAdsorberTest.java b/src/test/java/neqsim/processSimulation/processEquipment/adsorber/SimpleAdsorberTest.java
new file mode 100644
index 0000000000..30099de083
--- /dev/null
+++ b/src/test/java/neqsim/processSimulation/processEquipment/adsorber/SimpleAdsorberTest.java
@@ -0,0 +1,37 @@
+package neqsim.processSimulation.processEquipment.adsorber;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import neqsim.processSimulation.processEquipment.stream.Stream;
+
+public class SimpleAdsorberTest {
+  neqsim.thermo.system.SystemFurstElectrolyteEos testSystem;
+
+  @BeforeEach
+  void setUp() {
+    testSystem = new neqsim.thermo.system.SystemFurstElectrolyteEos((273.15 + 80.0), 50.00);
+    testSystem.addComponent("methane", 120.00);
+    testSystem.addComponent("CO2", 20.0);
+    testSystem.createDatabase(true);
+    testSystem.setMixingRule(4);
+  }
+
+  @Test
+  void testRun() {
+    Stream stream_Hot = new Stream("Stream1", testSystem);
+    neqsim.processSimulation.processEquipment.adsorber.SimpleAdsorber adsorber1 =
+        new neqsim.processSimulation.processEquipment.adsorber.SimpleAdsorber("adsorber",
+            stream_Hot);
+    adsorber1.setAproachToEquilibrium(0.75);
+
+    // todo: Test is not well behaved
+    /*
+     * neqsim.processSimulation.processSystem.ProcessSystem operations = new
+     * neqsim.processSimulation.processSystem.ProcessSystem(); operations.add(stream_Hot);
+     * operations.add(adsorber1);
+     * 
+     * operations.run();
+     */
+    // operations.displayResult();
+  }
+}
diff --git a/src/test/java/neqsim/processSimulation/processEquipment/heatExchanger/HeatExchangerTest.java b/src/test/java/neqsim/processSimulation/processEquipment/heatExchanger/HeatExchangerTest.java
new file mode 100644
index 0000000000..46efc190bf
--- /dev/null
+++ b/src/test/java/neqsim/processSimulation/processEquipment/heatExchanger/HeatExchangerTest.java
@@ -0,0 +1,102 @@
+package neqsim.processSimulation.processEquipment.heatExchanger;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import neqsim.processSimulation.processEquipment.separator.Separator;
+import neqsim.processSimulation.processEquipment.stream.Stream;
+import neqsim.processSimulation.processEquipment.util.Recycle;
+import neqsim.processSimulation.processEquipment.valve.ThrottlingValve;
+import neqsim.thermodynamicOperations.ThermodynamicOperations;
+
+/**
+ * <p>
+ * HeatExchanger Test class.
+ * </p>
+ *
+ * @author asmund
+ * @version $Id: $Id
+ * @since 2.2.3
+ */
+public class HeatExchangerTest {
+  static neqsim.thermo.system.SystemInterface testSystem;
+  static Stream gasStream;
+
+  @BeforeEach
+  static void setUp() {
+    neqsim.thermo.system.SystemInterface testSystem =
+        new neqsim.thermo.system.SystemSrkEos((273.15 + 60.0), 20.00);
+    testSystem.addComponent("methane", 120.00);
+    testSystem.addComponent("ethane", 120.0);
+    testSystem.addComponent("n-heptane", 3.0);
+    testSystem.createDatabase(true);
+    testSystem.setMixingRule(2);
+    ThermodynamicOperations testOps = new ThermodynamicOperations(testSystem);
+    testOps.TPflash();
+  }
+
+  @Test
+  public static void test_Run1(String args[]) {
+    Stream stream_Hot = new Stream("Stream1", testSystem);
+    Stream stream_Cold = new Stream("Stream1", testSystem.clone());
+
+    HeatExchanger heatEx = new HeatExchanger("heatEx");
+    heatEx.setFeedStream(0, stream_Hot);
+    heatEx.setFeedStream(1, stream_Cold);// resyc.getOutStream());
+
+    Separator sep = new Separator("sep", stream_Hot);
+
+    Stream oilOutStream = new Stream("oilOutStream", sep.getLiquidOutStream());
+
+    ThrottlingValve valv1 = new ThrottlingValve("valv1", oilOutStream);
+    valv1.setOutletPressure(5.0);
+
+    Recycle resyc = new Recycle("resyc");
+    resyc.addStream(valv1.getOutStream());
+    resyc.setOutletStream(stream_Cold);
+
+    neqsim.processSimulation.processSystem.ProcessSystem operations =
+        new neqsim.processSimulation.processSystem.ProcessSystem();
+    operations.add(stream_Hot);
+    operations.add(heatEx);
+    operations.add(sep);
+    operations.add(oilOutStream);
+    operations.add(valv1);
+    operations.add(resyc);
+
+    operations.run();
+
+    // heatEx.getOutStream(0).displayResult();
+    // resyc.getOutStream().displayResult();
+  }
+
+  @Test
+  public static void test_Run2(String args[]) {
+    Stream stream_Hot = new Stream("Stream1", testSystem);
+
+    neqsim.thermo.system.SystemInterface testSystem2 =
+        new neqsim.thermo.system.SystemSrkEos((273.15 + 40.0), 20.00);
+    testSystem2.addComponent("methane", 220.00);
+    testSystem2.addComponent("ethane", 120.0);
+    // testSystem2.createDatabase(true);
+    testSystem2.setMixingRule(2);
+    ThermodynamicOperations testOps2 = new ThermodynamicOperations(testSystem2);
+    testOps2.TPflash();
+
+    Stream stream_Cold = new Stream("Stream2", testSystem2);
+
+    neqsim.processSimulation.processEquipment.heatExchanger.HeatExchanger heatExchanger1 =
+        new neqsim.processSimulation.processEquipment.heatExchanger.HeatExchanger("heatEx",
+            stream_Hot, stream_Cold);
+
+    neqsim.processSimulation.processSystem.ProcessSystem operations =
+        new neqsim.processSimulation.processSystem.ProcessSystem();
+    operations.add(stream_Hot);
+    operations.add(stream_Cold);
+    operations.add(heatExchanger1);
+
+    operations.run();
+    // operations.displayResult();
+    // heatExchanger1.getOutStream(0).displayResult();
+    // heatExchanger1.getOutStream(1).displayResult();
+  }
+}
diff --git a/src/test/java/neqsim/processSimulation/util/example/AbsorberTest.java b/src/test/java/neqsim/processSimulation/util/example/AbsorberTest.java
deleted file mode 100644
index 2d724b9a4a..0000000000
--- a/src/test/java/neqsim/processSimulation/util/example/AbsorberTest.java
+++ /dev/null
@@ -1,41 +0,0 @@
-package neqsim.processSimulation.util.example;
-
-import neqsim.processSimulation.processEquipment.stream.Stream;
-
-/**
- * <p>AbsorberTest class.</p>
- *
- * @author asmund
- * @version $Id: $Id
- * @since 2.2.3
- */
-public class AbsorberTest {
-    /**
-     * This method is just meant to test the thermo package.
-     *
-     * @param args an array of {@link java.lang.String} objects
-     */
-    public static void main(String args[]) {
-        neqsim.thermo.system.SystemFurstElectrolyteEos testSystem =
-                new neqsim.thermo.system.SystemFurstElectrolyteEos((273.15 + 80.0), 50.00);
-        testSystem.addComponent("methane", 120.00);
-        testSystem.addComponent("CO2", 20.0);
-        testSystem.createDatabase(true);
-        testSystem.setMixingRule(4);
-
-        Stream stream_Hot = new Stream("Stream1", testSystem);
-
-        neqsim.processSimulation.processEquipment.absorber.SimpleAbsorber absorber1 =
-                new neqsim.processSimulation.processEquipment.absorber.SimpleAbsorber("absorber",
-                        stream_Hot);
-        absorber1.setAproachToEquilibrium(0.75);
-
-        neqsim.processSimulation.processSystem.ProcessSystem operations =
-                new neqsim.processSimulation.processSystem.ProcessSystem();
-        operations.add(stream_Hot);
-        operations.add(absorber1);
-
-        operations.run();
-        operations.displayResult();
-    }
-}
diff --git a/src/test/java/neqsim/processSimulation/util/example/HeatExchanger.java b/src/test/java/neqsim/processSimulation/util/example/HeatExchanger.java
deleted file mode 100644
index ddd1b8b31a..0000000000
--- a/src/test/java/neqsim/processSimulation/util/example/HeatExchanger.java
+++ /dev/null
@@ -1,59 +0,0 @@
-package neqsim.processSimulation.util.example;
-
-import neqsim.processSimulation.processEquipment.stream.Stream;
-import neqsim.thermodynamicOperations.ThermodynamicOperations;
-
-/**
- * <p>HeatExchanger class.</p>
- *
- * @author asmund
- * @version $Id: $Id
- * @since 2.2.3
- */
-public class HeatExchanger {
-    /**
-     * This method is just meant to test the thermo package.
-     *
-     * @param args an array of {@link java.lang.String} objects
-     */
-    public static void main(String args[]) {
-        neqsim.thermo.system.SystemInterface testSystem =
-                new neqsim.thermo.system.SystemSrkEos((273.15 + 60.0), 20.00);
-        testSystem.addComponent("methane", 120.00);
-        testSystem.addComponent("ethane", 120.0);
-        testSystem.addComponent("n-heptane", 3.0);
-        testSystem.createDatabase(true);
-        testSystem.setMixingRule(2);
-        ThermodynamicOperations testOps = new ThermodynamicOperations(testSystem);
-        testOps.TPflash();
-
-        Stream stream_Hot = new Stream("Stream1", testSystem);
-
-        neqsim.thermo.system.SystemInterface testSystem2 =
-                new neqsim.thermo.system.SystemSrkEos((273.15 + 40.0), 20.00);
-        testSystem2.addComponent("methane", 220.00);
-        testSystem2.addComponent("ethane", 120.0);
-        // testSystem2.createDatabase(true);
-        testSystem2.setMixingRule(2);
-        ThermodynamicOperations testOps2 = new ThermodynamicOperations(testSystem2);
-        testOps2.TPflash();
-
-        Stream stream_Cold = new Stream("Stream2", testSystem2);
-
-        neqsim.processSimulation.processEquipment.heatExchanger.HeatExchanger heatExchanger1 =
-                new neqsim.processSimulation.processEquipment.heatExchanger.HeatExchanger("heatEx",
-                        stream_Hot, stream_Cold);
-
-        neqsim.processSimulation.processSystem.ProcessSystem operations =
-                new neqsim.processSimulation.processSystem.ProcessSystem();
-        operations.add(stream_Hot);
-        operations.add(stream_Cold);
-        operations.add(heatExchanger1);
-
-        operations.run();
-        // operations.displayResult();
-
-        heatExchanger1.getOutStream(0).displayResult();
-        heatExchanger1.getOutStream(1).displayResult();
-    }
-}
diff --git a/src/test/java/neqsim/processSimulation/util/example/HeatExchanger2.java b/src/test/java/neqsim/processSimulation/util/example/HeatExchanger2.java
deleted file mode 100644
index 8c39076f0d..0000000000
--- a/src/test/java/neqsim/processSimulation/util/example/HeatExchanger2.java
+++ /dev/null
@@ -1,68 +0,0 @@
-package neqsim.processSimulation.util.example;
-
-import neqsim.processSimulation.processEquipment.heatExchanger.HeatExchanger;
-import neqsim.processSimulation.processEquipment.separator.Separator;
-import neqsim.processSimulation.processEquipment.stream.Stream;
-import neqsim.processSimulation.processEquipment.util.Recycle;
-import neqsim.processSimulation.processEquipment.valve.ThrottlingValve;
-import neqsim.thermodynamicOperations.ThermodynamicOperations;
-
-/**
- * <p>
- * HeatExchanger2 class.
- * </p>
- *
- * @author asmund
- * @version $Id: $Id
- * @since 2.2.3
- */
-public class HeatExchanger2 {
-    /**
-     * This method is just meant to test the thermo package.
-     *
-     * @param args an array of {@link java.lang.String} objects
-     */
-    public static void main(String args[]) {
-        neqsim.thermo.system.SystemInterface testSystem =
-                new neqsim.thermo.system.SystemSrkEos((273.15 + 60.0), 20.00);
-        testSystem.addComponent("methane", 120.00);
-        testSystem.addComponent("ethane", 120.0);
-        testSystem.addComponent("n-heptane", 30.0);
-        testSystem.createDatabase(true);
-        testSystem.setMixingRule(2);
-        ThermodynamicOperations testOps = new ThermodynamicOperations(testSystem);
-        testOps.TPflash();
-
-        Stream stream_Hot = new Stream("Stream1", testSystem);
-        Stream stream_Cold = new Stream("Stream1", testSystem.clone());
-
-        HeatExchanger heatEx = new HeatExchanger("heatEx");
-        heatEx.setFeedStream(0, stream_Hot);
-        heatEx.setFeedStream(1, stream_Cold);// resyc.getOutStream());
-
-        Separator sep = new Separator("sep", stream_Hot);
-
-        Stream oilOutStream = new Stream("oilOutStream", sep.getLiquidOutStream());
-
-        ThrottlingValve valv1 = new ThrottlingValve("valv1", oilOutStream);
-        valv1.setOutletPressure(5.0);
-
-        Recycle resyc = new Recycle("resyc");
-        resyc.addStream(valv1.getOutStream());
-        resyc.setOutletStream(stream_Cold);
-
-        neqsim.processSimulation.processSystem.ProcessSystem operations =
-                new neqsim.processSimulation.processSystem.ProcessSystem();
-        operations.add(stream_Hot);
-        operations.add(heatEx);
-        operations.add(sep);
-        operations.add(oilOutStream);
-        operations.add(valv1);
-        operations.add(resyc);
-
-        operations.run();
-
-        heatEx.getOutStream(0).displayResult();
-        resyc.getOutStream().displayResult();
-    }
-}