During the entire operation of a set of equipment, which devices experience both positive pressure and negative pressure? ? ?
Thread Content
I saw this sentence earlier: The equipment may be in a negative pressure condition during operation or replacement； It may operate under negative pressure, but there are high-pressure conditions during steam purging; therefore, the strength under both of these design pressures needs to be calculated. May I ask which devices or what types of equipment operate under both positive and negative pressure? Could you provide some typical examples?
Some reactions require vacuum evacuation before initiation, followed by reaction under positive pressure. There are quite a few such reaction vessels.
Jacketed vessel, pressure vessel with intermediate head
Is what the poster is referring to the start of equipment operation and intermediate replacement, or something that occurs in an instantaneous situation? If it occurs in an instantaneous situation, is it still necessary to conduct strength calculations?
Containers in a vacuum state may occur during the operation.
From a technical perspective, there are many devices that have this function.:)
Indeed, buried storage tanks are generally at atmospheric pressure (with only a slight internal pressure), and the external pressure exerted by external loads such as soil usually leads to the provision of an access well for maintenance.
During steam purging, it is not sealed; after the purging is complete, sealing is required. At this point, as the temperature drops, the steam condenses, creating a negative pressure. Some units perform semi-vacuum verification. A conservative approach is to use full vacuum verification.
Buried oil tanks, operation wells, underwater containers; testing of the sealing devices inside these containers, effects of external loads, etc