API620 Low Pressure Storage Tanks for Cryogenic Liquid Storage

[leongw]

I am having two new tanks which are designed to API620 Appendix Q. The MAWP of this tank is 100mbarg which is equivalent to 1.45psig. I wish to know whether these tanks should be considered as pressure vessel if the design code is API620. Appreciate it if anyone can provide some explanation and reference documents for me to refer.

Thanks.

Leong

 

[JoeTank]

API-620 tanks are not considered as pressure vessels in the regulatory world. Most juridictions define pressure vessels as units that operate above 15 psig. API-620 covers the range of 0 to 15 psig. Think of API-620 as bridging the gap between API-650 atmospheric storage tanks and ASME pressure vessels.

Joe Tank

 

[LSThill]

TECHNICAL REVIEW (NFPA 59a)

 

[MJCronin]

leong..


Joe Tank, as always, is correct.

In the USA, the term "Pressure vessel" refers to a container, above a certain minimum volume that normally operates above 15 psig.

The most common design code used in the USA for unfired pressure vessels is ASME Section VIII.

When the "pressure vessel" is fired, it is reffered to as a "boiler" and is designed to ASME Section I.

Everything else....is a "tank"

-MJC