Tank pipe 1

[simplemath]

How can the design P be determined for a tank ?

Tank design P is 2.5psi and tank is for LNG storage.

I went over API-620 and did not see the related requirement. Instead , API-620 has minimum wall thickness requirement.Should I calculate from thickness to design pressure and then operating pressure?

Do any other codes cover this aspect?

 

[JoeTank]

One needs to consider the vapor pressure curve for a product in order to know the gas pressure Pg for design. In the case of LNG it will be dependent on storage temperature. If stored at about -260F, the gas pressure will be in the range of about 2 to 2.5 psi. That data point is based on my memory, so if someone has better info to offer please do so. The design pressure for each shell course wil be the static head pressure + gas pressure. The calculation should be made for the lowest point of each shell course.

Joe Tank

 

[simplemath]

Thanks,JoeTank.
I just realized I can not change my thread here!
Missing a keyword in my thread. Sorry for confusing.
Rephase below.
"How can the design P be determined for the piping connecting to a tank ?

Tank design P is 2.5psi and tank is for LNG storage.

I went over API-620 and did not see the piping design P related. Instead , API-620 has minimum pipe wall thickness requirement.Should I calculate from thickness to design pressure and then operating pressure for the connecting piping?
Say, piping for discharge and loading.

Do any other codes cover piping connecting to the tank and its pressure rating?"

Thanks

 

[LSThill]

Review NFPA 59A

Leonard Thill