Standard industrial centrifugal pumps that isolate process material (i.e. "deadheaded" with both suction and discharge valves closed) inside the pump casing can explode catastrophically if the pump is inadvertently started and left running. Case histories and lessons learned at Tennessee Eastman Division (TED) involving pump explosions while running isolated will be presented in this paper. Case histories involve both combutstible and non-combustible process streams where the pump was inadvertently, started and allowed to run isolated until the process material heated up and built enough pressure to rupture the pump housing creating a BLEVE (Boiling Liquid Expanding Vapor Explosion). Incident learnings will be presented for each case.