Pressure vessels liquid holding time

The lid was then bolted shut. Using the precalibrated ammonia sample cylinders, the predetermined amount of liquid ammonia was delivered to the vessel. The vessel was heated by a 400-W Parr heating mantle to the desired temperature. After holding the vessel at the target temperature for the selected residence time, the exhaust valve was rapidly opened to relieve the pressure and accomplish the explosion. Both pressure and temperature drop very rapidly. The treated samples were removed and allowed to stand overnight in a fume hood to evaporate the residual ammonia. 

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