diff --git a/wntr/metrics/topographic.py b/wntr/metrics/topographic.py
index 7741b4d50..a1f291b21 100644
--- a/wntr/metrics/topographic.py
+++ b/wntr/metrics/topographic.py
@@ -269,7 +269,7 @@ def valve_segments(G, valve_layer):
         # and label link and unvalved node together
         if link_valves.shape[0] == 1:
             both_node_names = [node1_name, node2_name]
-            valved_node_name = link_valves.iloc[0][1]
+            valved_node_name = link_valves.iloc[0]['node']
             both_node_names.remove(valved_node_name)
             unvalved_node_name = both_node_names[0]
             unvalved_node_index = all_names.index('N_'+unvalved_node_name)
@@ -281,7 +281,7 @@ def valve_segments(G, valve_layer):
                 seg_label[link_index] = seg_label[unvalved_node_index]
 
         # Links with link_valves.size == 2 are already labelled (isolated link)
-        elif link_valves.shape[0] ==2:
+        elif link_valves.shape[0] == 2:
             continue
         else:
             raise Exception("Each link should have a maximum of two valves.")