# load checkpoint or saved_model
restorer = tf.train.import_meta_graph('./model.meta')
graph = tf.get_default_graph()
graph.as_default()

#print node names
print_nodes_name(graph)

# cut it after the first layer
nodes_to_conserve = ['model/conv1/Relu']

# extract subgraph
subgraph = tf.graph_util.extract_sub_graph(graph.as_graph_def(), nodes_to_conserve)

# for the second time
print_nodes_name(graph)

with tf.Session(graph=tf.graph_util.import_graph_def(subgraph)) as sess:
    ...