28 replies to this topic

[proinwv]

Jesus,

 

Section A.1 lists the conditions that allow the use of Annex A. Further, A.1.3 then states that if these conditions are not met, the "...the user should refer to the body of this International Standard...".

 

If you are confused about a certain part of A.1 I suggest you address your concern specifically and then I feel certain that you will be given some guidance from one of the very capable engineers on this forum

 

Paul

[jmouendo]

Paul,

 

Thank you. Indeed, part A.1 is quite clear. However, I have another question:

 

Equations in API standard 2000 for calculations of out-breathing and inbreathing venting requirements are for products stored below 104°F or with a vapour pressure less than 0.73 psi. What to do if none of these two conditions is met?

 

Regards,

 

Jesus

Edited by jmouendo, 20 August 2013 - 04:20 PM.

[Olidin]

Jesus,
 
I'm assuming you are talking about inbreathing/outbreathing due to liquid transfer in API 2000 Section 4.3.2.2. Stored liquid temperature and volatilities were not mentioned as limitations for the inbreathing due to liquid transfer calculations (API 2000 Section 4.3.2.2.2).  For outbreathing, API 2000 Section 4.3.2.2.1 also answered your question:

4.3.2.2.1 Out-breathing 
....
b. For products containing more volatile components or dissolved gases (e.g. oil spiked with methane), perform a flash calculation and increase the out-breathing venting requirements accordingly. 
c. For products stored above 40 °C (104 °F) or with a vapour pressure greater than 5,0 kPa (0,73 psi), increase the out-breathing by the evaporation rate.

Edited by Olidin, 26 August 2013 - 08:13 AM.

[Human.being]

Hello everybody,

 

This is my first post to your great fourm.

 

 I have learned so much from your fourm in the past few weeks , so I would like to have an input that might be relevant to this discussion ,

I know it has been over a year and you have probably finished this design somehow , but I believe it won't hurt to have an input.

 

to keep it short ; I has encounterd the same design issue few days ago , in my search i have found this discussion along with other sources and refrences that were helpful

my conclusion was :

 

 An atmoshperic tank designed to API 650 basic requirements is able by -default- to

1- maintain an internal pressure not exceeding the weight of the tank roof , See 1.1.1 in API-650

 

2- maintain a partial vacuum of 0.25 kPa (1 inch of water) without the need of any extra calculations . See 5.2.b in API-650

 

The above is what I believe to be right and what I shall base my vent sizing on , I'm not an expert after all .

 

Best regards