API 650 Nozzle Elevation Requirents

[Cristian N]

With regard to the required nozzle dimensions shown on Table 5.6A/B, would it be fair to say that the table doesn't actually provide a Minimum Distance from Bottom of Tank to Center o Nozzle value for small-bore nozzles? i.e.; less than 2" NPS.

From my understanding columns 8 and 9 provide values under the premises that the small-bore nozzles were installed with some type of reinforcement. However, since most tank construction companies aren't required to install reinforcement on nozzles < 2", most simply don't. There for these values may not apply to unreinforced small-bore nozzles?
Taking this into account, I would assume one must then refer to Figure 5.6 to acquire some type of value that would provide spacing limitations from the tank bottom to the unreinforced nozzle.

Essentially, what I am getting at is, Per 650, what would be an applicable value to adhere to in place of columns 8 & 9?

 

[IFRs]

The tables go down to 3/4" nozzles for regular height installations, and direct you to section 5.7.3 and figure 5.6 for low-type elevations. What am I missing?

 

[Cristian N]

IFR

From my understanding the table refers to low or regular type reinforced nozzles. What I'm asking is what about unreinforced nozzles <= 2", do they have a minimum elevation centerline? From my understanding Figure 5.6
provides minimum weld spacing from the tank bottom to the bottom toe of the unreinforced nozzle (S-N). But that's about it.
It still doesn't answer my question whether there is a set minimum nozzle elevation centerline for unreinforced nozzles.

 

[HTURKAK]

Yes.. THEY DO HAVE..

Figure 5-8 shows the applicable Shell Nozzles and you must comply with the requirements of the standard to API 650 tank. What is your thought ? are you planning tapping the shell to avoid the welding limitations?..I will suggest you to look scope and limitations .

 

[IFRs]

The tables are for all nozzles. Small nozzles are often self reinforcing. Use 5.7.3 to find out.