I am looking at installing a natural gas blanketing system on a spherical butane tank. The purpose of this blanket is to avoid pulling vacuum in the tank during pump-out and cold weather.
I need to do some calculations for the amount of gas needed, and to determine if we could encounter butane spec problems by use a blanket gas. We are not at a detailed design phase yet - I am doing a rough analysis to rule out (or identify) any potential supply or quality problems.
I know that API2000 provides some calculations for determining thermal inbreathing and outbreathing calculations on low pressure storage tanks, but its scope is limited to tanks rated up to 15 psig. Is there a different API or ASME specification that would be better suited to a high pressure tank (MAWP is closer to 50-100 psig) that , or is API2000 adequate for a first pass?
Thank you for your help.