Abstract: At approximately 6:42 p.m. on July 27, 2006, Employee #1, an instrument technician, was working for an oil refinery that was involved in processing hydrogen to a higher purity. This process is done in the PSA SKID. There are 72 valves in this area which are controlled by computers. The exact timing of the opening and closing of these control valves is critical to refinery operations otherwise the process will shut down. Employee #1 was calibrating control valve number 611, which was observed the previous day not closing completely. Upon arriving in the area, he requested the unit operator to take valve number 611 out of the computer's control so he could work on it. After it was taken out of service, the employee disconnected the signal airline and replaced it with a hand controlled pressure calibrator. Kneeling in front of the unit, the employee started pumping pressure to open the valve. He could not determine where the valve actually started opening because of his position and the location of the stem. So, he placed his right middle finger on the block indicator to try to sense its movement. After he got the valve to open at 100, he released the pressure on his left hand (the hand which was controlling the pressure pump) and the valve closed immediately after that. His middle finger was caught between the block and the base of the stem of the valve. The employee pulled his finger out and finished calibrating. When he was done, he realized that he had cut the distal end of his right middle finger off. Employee #1 was hospitalized.