A minimum permissible temperature is required to be displayed on the nameplate of a Division 2 vessel. Unlike the nameplate for a Division 1 vessel,…
Division 2 requires that the design temperature “shall be based upon the actual metal temperature expected under operating conditions,” and should be determined from the…
Hydrotesting a pressure vessel should never be performed at an ambient temperature below the minimum design metal temperature. The high stresses developed during a hydrotest…
The autorefrigeration temperature is defined as the temperature that the contents of a vessel would reach if the vessel is depressured to 40% of the…
Most pressure vessels in locations with a mild winter climate will not require special materials selection or CV-impact testing to assure adequate resistance to brittle…
Pressure vessels that are installed at geographic locations with severe winter climates may be required to be at maximum operating pressure at low ambient temperatures…
Pressure vessels that will be in continuous operation at temperatures below normal ambient temperatures are considered to be in “critical” service because of the risk…
The minimum design metal temperature (MDMT) is defined in Division 1 as “the lowest (temperature) expected in service.” This temperature is essentially the same as…
The maximum design temperature is based on the normal maximum operating temperature obtained from the process design. The recommended practice is to add a margin…
Many pressure vessels are designed to operate at high temperatures, but are usually required to be under pressure at ambient temperature during startup and/or shutdown…