Which is the best method to drill 300mm. holes on a mild steel vessel
30mm thick ?
Thanks in advance.
Sel=E7uk SANCAK
- posted
15 years ago
How to drill big holes on a vessel ?
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- posted
15 years ago
Perhaps using a big plasma cutter?
i
i
- posted
15 years ago
Thanks for the suggestion.I am wondering if there is a big drill
machine which can be temporarily fixed to the vessel wall ?
Thanks again
Thanks again
- posted
15 years ago
300 is awfully big for any kind of hole saw or single point cutter not
mounted on a fairly rigid machine. And if the surface is at all
curved, good luck...
How about drilling a bunch of holes arounc the circumference and then connecting them with some sort of saw? Clean up with a grinder. Not fast, but will get the job done using widely available tools (probalby go through a few drillbits though)
Don't know much about them, but the plasma or flame cutting ideas sound worth looking into.
How about drilling a bunch of holes arounc the circumference and then connecting them with some sort of saw? Clean up with a grinder. Not fast, but will get the job done using widely available tools (probalby go through a few drillbits though)
Don't know much about them, but the plasma or flame cutting ideas sound worth looking into.
- posted
15 years ago
Thanks.That's how (small holes+grinder) we are making these holes
these days. But as you mention, it is not fast. =DDnstead of drillbit a
blade turning in this diameter perhaps would be helpfull.But I don't
know who,where,how ?
- posted
15 years ago
Before you do anything to this tin-can, please advise what it is used
for. With a 30 mm wall thickness is it perhaps used as a pressure
vessel, ie. subjected to internal or possibly external pressure? If
so, all bets are off regarding the cutting of ANY holes, unless they
meet the requirements of the ASME Boiler & Pressure Vessel Code as to
size and / or reinforcement requirements.
The ASME Code is a legal requirement in all US states and all provinces of Canada, also many foreign countries. Fooling around with pressure vessels is not something to do on the fly or by guess and by gum.
Wolfgang
The ASME Code is a legal requirement in all US states and all provinces of Canada, also many foreign countries. Fooling around with pressure vessels is not something to do on the fly or by guess and by gum.
Wolfgang
- posted
15 years ago
If you want to do the torch route;
Google "torch circle cutting guide"
They have them for plasma cutters
Princess auto (in Canada) has them for oxy/acetylene torches for
$20.00
or, maybe build something along these lines;
or, maybe build something along these lines;
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THAT'd be a scary sucker to see in action- posted
15 years ago
Thanks Wolfgang.For your information;Yes, these vessels are
pressurized and sometimes are boilers.They are not subjected to ASME
codes.I am not responsible for the whole production.Responsible just
for searching a drilling method for these holes.
- posted
15 years ago
But it wont work.Because the surface is not perpandicular to the
centerline of the hole.
- posted
15 years ago
Which is the best method to drill 300mm. holes on a mild steel vessel
30mm thick ?
Thanks in advance.
Selçuk SANCAK
How many holes? One? or 100? How much money can you spend? Oxy/acetylene torch or plasma seems to me to be the best bet. It would need to be a pretty good plasma to cut 30 mm thick material though. Drilling one hole that size is out of the question as far as I know. Hole saw would work with thin material, but 30 mm thick material kills the hole saw idea. Greg
Thanks in advance.
Selçuk SANCAK
How many holes? One? or 100? How much money can you spend? Oxy/acetylene torch or plasma seems to me to be the best bet. It would need to be a pretty good plasma to cut 30 mm thick material though. Drilling one hole that size is out of the question as far as I know. Hole saw would work with thin material, but 30 mm thick material kills the hole saw idea. Greg
- posted
15 years ago
The best method I know to cut heavy carbon steel is oxy-fuel torch.
You could jury-rig a radius arm carrying the torch, by tack-welding
the pivot block to the centre of the hole-to-be. By allowing the arm
to pivot in a vertical plane you can maintain the torch-to-surface
distance. Practice a couple of times on a scrap piece to get the
motion speed right.....radial chalk marks help to set the pace, in
conjunction with a second-hand clock.
If you have many holes to cut like this, purchase the appropriate equipment, which is a circular track held in place by magnets or tack welds, on which a self-propelled trolley carries the torch. In this case the radius arm points inward with the cutting torch on the inside end. Flexible tracks are also available to follow irregular or 3- dimensional contours. Again, practice on scrap and make set-up instructions to help speed-up the process the next time.
Wolfgang
P=2ES.: If it is a pressure vessel not subject to the ASME Code, to what code is the vessel built? Just curious.
If you have many holes to cut like this, purchase the appropriate equipment, which is a circular track held in place by magnets or tack welds, on which a self-propelled trolley carries the torch. In this case the radius arm points inward with the cutting torch on the inside end. Flexible tracks are also available to follow irregular or 3- dimensional contours. Again, practice on scrap and make set-up instructions to help speed-up the process the next time.
Wolfgang
P=2ES.: If it is a pressure vessel not subject to the ASME Code, to what code is the vessel built? Just curious.
- posted
15 years ago
O/A torch. Can you cut from the inside to blow the crap outward? A trick
is to "draw" the circle for the hole (undersize) then make a series of
center punch marks on it. Be sure to project the pattern "straight down"
onto the surface, don't allow your pattern to bend with the surface or
you'll never get a tube, for instance, to fit into the hole. The line
will disappear but the marks won't. You'll need to grind the hole to
size both for smoothness and to remove the flame hardened edge.
Randy R
- posted
15 years ago
So the hole is not circular? Is the surface flat, or
curved? Is it a compound curve?
- posted
15 years ago
We build tanks where I work although they are only 1/4 thick max. We
are going to possibly be doing over 1/2 in. Now they cut holes by hand
with plasma torch. Drilling isn't going to work, its not practicle, so
forget it.
We are going to start buring the holes before they are rolled with a
CNC plasma cutting table. You asked for the best method. This is it.
It sure ain't the cheapest but quality is going to be much better and
much much more efficient. Outside of that the plasma circle cutter
post is 2nd best idea
Rosco,
- posted
15 years ago
Which is the best method to drill 300mm. holes on a mild steel vessel
30mm thick ?
Thanks in advance.
One thing that might work would be a diamond core drill. Often these are used for drilling large holes in concrete slabs, but the rig they use is portable and if you were to make a fixture to hold the rig perpendicular to the hole, you should get a nice clean hole.
Thanks in advance.
One thing that might work would be a diamond core drill. Often these are used for drilling large holes in concrete slabs, but the rig they use is portable and if you were to make a fixture to hold the rig perpendicular to the hole, you should get a nice clean hole.
- posted
15 years ago
Exocet.
John Martin
John Martin
- posted
15 years ago
Brilliant :) Let me check if there is one in the warehouse.
- posted
15 years ago
Exocet would be fast.
Here is a more serious alternative: could you trepan it? Trepaning is commonly used to cut disks from glass sheets 300 mm diameter and 30 mm thick. The standard method would be to use a disk the size of the hole and attach a rim of harder material. (For glass a thin piece of steel will work. I do not know what I would recommend for cutting steel--perhaps it will not work because no materials are suitable.) Then one mounts it on the surface with a very slow drill and adds SiC slurry in water to do the actual cutting. The cutting is done by grinding and the cutting rim wears away and can be replaced as needed. The power requirements are low, but you would need to firmly mount your drill press. On glass you might use 50-100 rpm. It leaves a nice round hole. This method would work on a curved surface.
Another simple hole cutting idea that will probably cause bodily injury on your project is a router with a carbide bit and a good hole cutting attachment. It works great for cutting 15 mm Al disks. It is fast, noisy and scary.
Scott
Here is a more serious alternative: could you trepan it? Trepaning is commonly used to cut disks from glass sheets 300 mm diameter and 30 mm thick. The standard method would be to use a disk the size of the hole and attach a rim of harder material. (For glass a thin piece of steel will work. I do not know what I would recommend for cutting steel--perhaps it will not work because no materials are suitable.) Then one mounts it on the surface with a very slow drill and adds SiC slurry in water to do the actual cutting. The cutting is done by grinding and the cutting rim wears away and can be replaced as needed. The power requirements are low, but you would need to firmly mount your drill press. On glass you might use 50-100 rpm. It leaves a nice round hole. This method would work on a curved surface.
Another simple hole cutting idea that will probably cause bodily injury on your project is a router with a carbide bit and a good hole cutting attachment. It works great for cutting 15 mm Al disks. It is fast, noisy and scary.
Scott