Installing 10" Nozzle through 22" manway...reinforcement calc?
Installing 10" Nozzle through 22" manway...reinforcement calc?
(OP)
I have been asked to review a planned modification to a vessel.
The vessel currently has a 22" flange that is blinded off with a bolted 22" 300# flange. I can't find much data on 22" flange sizes as they are not a standard size.
They are planning to cut a hole in the center of the blind flange and insert a 10" pipe that will protrude into the nozzle. They are going to weld a flange onto the end of the pipe and install piping to it. (pretty much fabricating a nozzle and attaching it to the blind)
According Section VIII D1 UG-39(b)(1)....doing this is acceptable but requires a repad. There is an equation for the required cross sectional area of the repad......
My questions are:
1) The equation contains a variable (t), required thickness of blind flange. If the actual thickness of the blind flange is larger than the required....can this be taken into account? If so, how?
2) The calculation for the required thickness in UG-34 includes a variable (E), joint efficiency factor. What is the joint efficiency factor for a bolted structure?
3) I need dimensional info on the flange for the calculation...like the gasket moment arm....any idea where I can find dimension for 22" flanges...or do you think this was special fabrication?
The vessel currently has a 22" flange that is blinded off with a bolted 22" 300# flange. I can't find much data on 22" flange sizes as they are not a standard size.
They are planning to cut a hole in the center of the blind flange and insert a 10" pipe that will protrude into the nozzle. They are going to weld a flange onto the end of the pipe and install piping to it. (pretty much fabricating a nozzle and attaching it to the blind)
According Section VIII D1 UG-39(b)(1)....doing this is acceptable but requires a repad. There is an equation for the required cross sectional area of the repad......
My questions are:
1) The equation contains a variable (t), required thickness of blind flange. If the actual thickness of the blind flange is larger than the required....can this be taken into account? If so, how?
2) The calculation for the required thickness in UG-34 includes a variable (E), joint efficiency factor. What is the joint efficiency factor for a bolted structure?
3) I need dimensional info on the flange for the calculation...like the gasket moment arm....any idea where I can find dimension for 22" flanges...or do you think this was special fabrication?





RE: Installing 10" Nozzle through 22" manway...reinforcement calc?
2.) No. The joint efficiency factor is welding joint efficiency of pipe to blind flange. This factor ranges from 0.5 to 1.0 depending up on welding joint. Hence please refer Table UW-12 for this stuff.
3.) Mate! This flange is standard flange. Both ANSI B16.5 and B16.47(series A)have standard data for that flange. I am attaching one good catalogue for your reference.
Good Luck!! Mate!
RE: Installing 10" Nozzle through 22" manway...reinforcement calc?
2)I understand that the joint efficiency factor is for welds....but when you are trying to calculate the required thickness of a blind flange that you are going to bolt to the nozzle...what weld do you need the efficiency for?
3) You say its standard but my ASME 16.5 goes up to 24" pipe but jumps from 20" to 24" and doesn't contain info for 22". The catalog you attached calles out ASME 16.47....which starts at 26". I will have to search for the ANSI standards and see if they include any info.
RE: Installing 10" Nozzle through 22" manway...reinforcement calc?
1) The difference between tr (min req'd thk) and t (actual thk, less any corrosion) is available for reinforcement of the opening, as per UG-37.
2) E for seamless parts is 1.0, if your blind were of welded construction, say if it were made of multiple pieces, the joint efficiency would apply.
3) Per Taylor Forge Catalog #571, 22"-300# per ANSI B16.5:
O = 33, C = 2.63, R = 25.25, BC = 29.25, 24 ea. 1 1/2" dia bolts. The moment arm hg will depend on actual gasket dimensions used. You may be able to get standards from the gasket makers, or ASME B16.20, B16.21.
Regards,
Mike
RE: Installing 10" Nozzle through 22" manway...reinforcement calc?
RE: Installing 10" Nozzle through 22" manway...reinforcement calc?
most likely a mss or something similar
pressure vessel handbook lists a 22" but says not standard
RE: Installing 10" Nozzle through 22" manway...reinforcement calc?
Note the ANSI reference. I think the 22" is an obsolete size. I have no idea how far back TF #571 goes.
Regards,
Mike
RE: Installing 10" Nozzle through 22" manway...reinforcement calc?
RE: Installing 10" Nozzle through 22" manway...reinforcement calc?
RE: Installing 10" Nozzle through 22" manway...reinforcement calc?
http://www.texasflange.com/Catalog.pdf
I'm on a older computer with a old Adobe Reader with an even older operator and can't read but few pages.