Pressure vessel Abbreviation

[Joli21]

Hi,
I came accross with a abbrivation in pressure vessel drawing in Torispherical head as below:
End 406 OD TORIS. x 9.53 MIN TH. 25 SF
what does "SF" stand for?

 

[dygorane]

Straight Flange

 

[Joli21]

Thanks very much, so how can i calculate "h" Deprth of the Torispherical dish with this data? 406 OD x 9.53 MIN TH .25 SF?

 

[vesselfab]

all head manufacturers use slightly different formulas.

a good rule of tthumb to get close

dish rad dr = diameter -6"
inside knuckle rad ikr = 0.06 x diameter

idd of head = dr - square root of [(dr-ikr)squared - (radius- ikr)squared

 

[Joli21]

Thanks very much indeed for your help.