A butterfly valve capable of preventing leakage under demanding environmental and operating conditions. The valve includes two stem seal assemblies. The stem seal assemblies include a first pusher, a first energizer, a second pusher, a second energizer, and a force transmitting member. The force transmitting member is configured to transfer an axial load to the second pusher, which causes the first and second energizer to expand radially to create a secondary and tertiary seals between the stem seal assembly and valve stem. In addition, the force transmitting member is configured to transfer an axial load to the first pusher which creates a primary seal.