Plate thickness at the end of pipe.
Plate thickness at the end of pipe.
(OP)
I'm struggling to find the plate thickness that I need to hold 10 bar in a 304l 2mm thick pipe. The plate will be welded on.
Can anyone pass on an equation to find the plate thickness?
Thanks,
Pete Hunt
Can anyone pass on an equation to find the plate thickness?
Thanks,
Pete Hunt





RE: Plate thickness at the end of pipe.
RE: Plate thickness at the end of pipe.
I'm currently searching though the companion guide to ASME, boiler and pressure code, but I can't seem to find any solution to my problem without it seems having to over complicate matters with flanges and the like.
RE: Plate thickness at the end of pipe.
RE: Plate thickness at the end of pipe.
The part is needed for a prototype. Once this proof of concept has been made, the professionals will be brought in.
RE: Plate thickness at the end of pipe.
Instead of proof, go to ASME B16.9 "Factory-Made Wrought Butt Welding Fittings" and purchase an SA 182 or SA 240 Grade 304L stainless steel butt welded hemi-head pipe cap. The cap should be for Class 300lb service or it could be lower rating if you know the design conditions - pressure and temperature.
RE: Plate thickness at the end of pipe.
If it makes a difference to your suggestions the item is at a pressure of 150PSI, at a temp of 300K, (25degsC)?
RE: Plate thickness at the end of pipe.
No, that's not right unless you have an impervium-coated impossibloadenum crystal vessel. Regardless of pipe (pressure vessel) OD.
RE: Plate thickness at the end of pipe.
RE: Plate thickness at the end of pipe.
After looking through ASME B16.9, I'm right in thinking I need a 6mm plate?
It's to be welded to a 2mm thickness 304l, 8inch OD pipe, needing to hold 10bar/140PSI.
RE: Plate thickness at the end of pipe.
RE: Plate thickness at the end of pipe.
RE: Plate thickness at the end of pipe.
They're suggestion was a 6mm thick flat 304l end plate, to hold the 150PSI. As they don't stock pressure rated end caps. (I presume there end caps are a miss match of quality/suppliers so they don't offer a rating on them.)I presume from your reaction this is totally wrong? Too thin?
So basically, I'm looking for what ever would be cheapest to produce in the long run. Welding would be in house, and everything has been sourced apart from the part in discussion. End cap or flat plate?
Would a SA 182 or SA 240 cap hold 150 PSI? I'm struggling to find any suppliers online that have a pressure rating in PSI/KSI/BAR on their website.
RE: Plate thickness at the end of pipe.
you said your using NPS 8" pipe? 304L?
Well fromt he tables ive found schedule 5 pipe in 8" size has a wall thickness of 2.77 mm which is greater than what you say you have (by about 38%)
So i guess my first question is have you fabricated your own pressure pipe from rolled plate here? if so who did the initial calculations ont he pipe itself? im just thinking that your bigger problem si you have pipe here that was not designed to any standard specification, which understadably does make it harder to do the calculations.
All that being said though B31.3 has the necessary calculations to determine the correct wall thickness of pipe andassuming the pipe will hold the pressure you need then a standard fitting will work.
I am a bit concerned though that you are looking at a 2mm WT pipe and thinking 6 mm end caps might be too thin here... yes pipe can be thinner than a flat plate, but still...
RE: Plate thickness at the end of pipe.
B16.9 fittings are rated as per the straight pipe they have been designated as - that is, you will not find an explicit pressure-temperature rating. Rather you will find them marked with a schedule number that means they will have the same capabilities of the equivalent straight pipe.
RE: Plate thickness at the end of pipe.
I realise the standard for 8" is 2.77mm, (The 2mm has been arranged for us and is pressure rated above the needed 150 KSI, it's also cheaper and lighter then the 2.77mm) which was why I was asking for the equation to do my own calculations in the first place as I realise using non standards will complicate things.
'I am a bit concerned though that you are looking at a 2mm WT pipe and thinking 6 mm end caps might be too thin here... yes pipe can be thinner than a flat plate, but still...'
I'm still not sure from both your comment and the previous one wether 6mm is too thick or too thin? As mentioned the 6mm was quoted from a suppiler.
RE: Plate thickness at the end of pipe.
SEE UG-34 from Section VIII Division 1 of ASME BPVC for the calculation!!!!!
Besides, you will HAVE TO go with this flat plate because there is no standard fitting for an OD of 8"
RE: Plate thickness at the end of pipe.
It is also unclear whether this is to be a Coded application, in which case you will have to use a pressure vessel Code, such as Sec VIII, Div 1, or perhaps a piping Code such as B31.3, or a non-Coded application, in which you can use whatever design methods you like.
As AllHandlesTaken says, UG-34 is usable for a Code application, if not Code, you could look at Roarke, Table 24, Case 2.
Regards,
Mike
RE: Plate thickness at the end of pipe.
RE: Plate thickness at the end of pipe.
jt
RE: Plate thickness at the end of pipe.
6mm = 1/4 plate and seems okay for the... I hope is water at 70-75F.
he's welding it to atube or rolled pc of sheet metal 2mm T.
if it washot water or others as steam, it would not pass but for water, no kiiling here.
I approve it.
genblr
RE: Plate thickness at the end of pipe.
Politely but firmly put, as I understand the geometry and pressures of his (mixed units!) proposal, I would not feel safe in a room or area near the piece being discussed, nor would I permit my construction crew to be near it under test pressure (! = 1.5 operational) and regular operational pressures. Even at low temp's and wet (none-compressible gas) conditions of temperature or fluid.
The tiny material savings of using "sheet metal", compared to the fabrication delays and difficulties of getting a sufficient weld deposit on between two thin-metal joints, then of testing and certifying such a little weld? Just buy a length of standard SS pipe, standard fittings. Get a result rated for the fluid pressures you have.
How are you going to attach pipe fittings to the sheet metal walls to let the gasses and test fluids get in and out of the fixture?