diff --git a/api/s5_pipes.py b/api/s5_pipes.py
index f9ca77c..63f36f8 100644
--- a/api/s5_pipes.py
+++ b/api/s5_pipes.py
@@ -14,6 +14,11 @@ def add_pipe(name: str, id: str, node1: str, node2: str, length: float = 0, diam
         return ChangeSet()
     if not is_node(name, node2):
         return ChangeSet()
+    if node1 == node2:
+        return ChangeSet()
+
+    if status != PIPE_STATUS_OPEN and status != PIPE_STATUS_CLOSED and status != PIPE_STATUS_CV:
+        return ChangeSet()
 
     sql = f"insert into pipes (id, node1, node2, length, diameter, roughness, minor_loss, status) values ('{id}', '{node1}', '{node2}', {length}, {diameter}, {roughness}, {minor_loss}, '{status}');"
     undo_sql = f'delete from pipes where id = "{id}";'
diff --git a/api/s6_pumps.py b/api/s6_pumps.py
index 6e7aefc..679bdac 100644
--- a/api/s6_pumps.py
+++ b/api/s6_pumps.py
@@ -9,6 +9,8 @@ def add_pump(name: str, id: str, node1: str, node2: str) -> ChangeSet:
         return ChangeSet()
     if not is_node(name, node2):
         return ChangeSet()
+    if node1 == node2:
+        return ChangeSet()
 
     sql = f"insert into pumps (id, node1, node2) values ('{id}', '{node1}', '{node2}'');"
     undo_sql = f'delete from pumps where id = "{id}";'
diff --git a/api/s7_valves.py b/api/s7_valves.py
index 7146562..adea81a 100644
--- a/api/s7_valves.py
+++ b/api/s7_valves.py
@@ -17,6 +17,8 @@ def add_valve(name: str, id: str, node1: str, node2: str, diameter: float = 0, t
         return ChangeSet()
     if not is_node(name, node2):
         return ChangeSet()
+    if node1 == node2:
+        return ChangeSet()
 
     sql = f"insert into valves (id, node1, node2, diameter, type, setting, minor_loss) values ('{id}', '{node1}', '{node2}', {diameter}, '{type}', {setting}, {minor_loss});"
     undo_sql = f'delete from valves where id = "{id}";'