- Hand Tools
- Construction Tools
Although most of the hydrogen fluoride piping system was open to the atmosphere before the elbow was cut, the lines were not purged. Two plugs of residual material on either side of the elbow remained in place, thus allowing hydrogen to be trapped in the elbow. In the future, piping systems containing hydrogen fluoride or other chemicals should be purged to ensure that they are free from hazards prior to starting D&D activities.