A ship’s engineer started a venturi pump in order to start the fresh water separator. After a while he checked for a vacuum but found that there was none. He stopped the pump and closed the suction valve. He then opened the top of the suction filter to see if it was clogged. Hot water washed over him and he was scalded on one arm, his stomach and one foot. The reason the suction filter contained hot water was that the pump was working against a closed pressure valve that the ship’s engineer had forgotten to open.