Term
In a cylindrical pressure vessel, what is the maximum normal stress? 

Definition
stress = pr/t
p = internal gauge pressure r = internal radius t = wall thickness 


Term
In a cylindrical pressure vessel, which stress is critical: the hoop stress or the longitudinal stress? 

Definition
The hoop stress is critical.
The hoop stress is twice the longitudinal stress. 


Term
A pressure vessel's wall is steel, and the allowable normal stress is 33 ksi.
You want to find the max. allowable pressure for the tank, and you compute 152.5 psi.
Would you report this as 152 psi or 153 psi? 

Definition
Round down to 152 psi. That is the direction of safety. 


Term
In a spherical pressure vessel, what is the maximum normal stress? 

Definition
stress = pr/2t
p = internal gauge pressure r = internal radius t = wall thickness 

