Change of service from anhydrous ammonia to propane

Unfired pressure vessels that have been previously used in anhydrous ammonia service may be converted to liquid petroleum service only with all of the following conditions being met: 1. The pressure vessel is American Society of Mechanical Engineers Code constructed and national board registered. 2. The pressure vessel has a manhole opening for access or a manhole opening is provided as an alteration. 3. The pressure vessel is in satisfactory condition internally and externally using the National Board Inspection Code to determine acceptable condition. 4. The pressure vessel has passed a wet fluorescent magnetic particle test made by an individual possessing a valid American society for nondestructive testing level II or Ill certificate issued in accordance with the requirements of the American society for nondestructive testing.