Full Vacuum Design

[Wrl69]

Hi, when I read a vessel´s Data Sheet about its design conditions (eg : 350psig, 180°F), could you tell me what means "Vessel to be design for full vacuum at ambient conditions"?

Thanks.

 

[JoeTank]

They intend for you to design the vessel for a vacuum (external pressure) of 14.7 psi (say 15 psi) at ambient temperatures (say 100F).

Steve Braune
Tank Industry Consultants

http://www.tankindustry.com

 

[codeeng]

Probably means the vessel will be subjected to steam-out. This will pull a vacuum as the steam cools and condenses. Sometimes the vacuum design is specified at the saturated steam temperature for convenience although I've seen lower temperatures (approaching ambient) when there is a cost impact to provide additional stiffening.

 

[TD2K]

A vessel designed for an internal pressure above atmospheric may not be able to withstand an internal vacuum when the atmospheric pressure is pressing in on it (okay, lousy terminology I know but it gets the point across).

As others have said, if you expect to have to or the possibility the vessel could have a partial/full vacuum in the vessel, you want to ensure the vessel is also designed for that condition.