Plasma safety

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Hi. Need to cut off some steel pipes inside a tank. Aside from the fumes issue (taken care of), are there any problems I need to address prior to climbing into a tank and cutting off a couple (2) sch40 pipes? The tank has steel legs and I plan to have a real clean tight ground. Seems like plasma cutters run on a different set or rules and are more likely to hurt somebody who doesn't really know what they're doing (me). Obviously I don't want to get zapped. Normally, I'd cut on a rubber mat and try not to make contact with the item I'm cutting. But with tank work I'll be sitting inside the thing I'm cutting. It's concerning...
Reply:I wouldn't be concerned as much about electrical safety as I would fumes and lack of breathable air.....Mike##EDIT##Sorry, didn't see the fumes were resolved, I'll shut up now :-)
Reply:Mike, Have you ever cut anything with a plasma like I describe (off the ground inside)? All set with air.
Reply:Yep, same setup other than being in the back of a dump body cutting pieces off and welded in the same scenario as well standing on the grounded steel....Mike
Reply:Cool Thanks. I shall proceed as planned and not worry about it.
Reply:Originally Posted by MoltenMetalCool Thanks. I shall proceed as planned and not worry about it.
Reply:I'm curious how you have the fume issue "taken care of"... There's a bit more to doing stuff like this in a confined space than jamming a fan in the hatch. Even when doing work where the welder was on full independent air  supply in a confined space, we always had at least one other person as a safety, usually two..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:D, Well yes, I have a fan stuffed in there with a hatch on the opposite side for cross ventilation. Not the best setup, but it's what I have to work with for two quick cuts. I just didn't want to get offtrack initially and stated it was taken care of. Understand the severe impacts of improper air supply. Will take me one minute or less to cut the two pipes off and I'm out.
Reply:Where I work, you can not go into a tank to cut/weld or work unless the tank is deemed safe for confined space entry. A confined space means one way in, one way out.Oxygen level in tank needs to be checked. Are there flammable gases in the tank? Are there corrosive or hazardous fluids in the tank? Has the tank been ventilated? Can any substance from inlet and outlet piping get into the tank while your working in there?Do you have a hole watch person on hand while you are working in the tank?It doesn't matter how fast you can do the job that needs to be done in this tank. If the conditions are not safe for entry, your risking your life...and that's just not worth it.Last edited by snoeproe; 11-24-2012 at 10:57 PM.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:Originally Posted by dave powelsonOkay--don't worry about it....but keep a close watch on how and whereall that cutting swarf is going--- bouncing, flying around inside the tank.Suggest wearing some PPE better than flip flops, tee shirt and shorts.
Reply:Originally Posted by MoltenMetalI just didn't want to get offtrack initially and stated it was taken care of. Understand the severe impacts of improper air supply. Will take me one minute or less to cut the two pipes off and I'm out.
Reply:What was/is in the tank? What was/is in the pipes? How will it react with the cutting process? I don't need an answer as it may be proprietary, but you do!Locked out? Tagged out? Blanked off? Air samples - pre entry, during entry. Who is the competent person? Who are the qualified monitors/entrants? Do you have a retrival system? What type of respirator is needed?I could go on but............ .   Two minutes of work? How long does it take to inhale one breath?  You get in the wrong stuff and your lungs will lock up. You won't be able to exhale or inhale. I know from experience. Your time to get out will be limited to the oxygen supply in your bloodstream - period. After that you pass out and you're done helping your self.Sorry if this seems like a bit of a rant, but confined space fatalities are ALL preventable.
Reply:Nothing but a limited amount of wood tar in the pipes and the tank. The two minutes figures getting in, cutting off two 2" sch-40 pipes and climbing out. The bottom of the tank has a good sized hatch and the entry is large enough to climb through. I'll have good ventilation from top to bottom and out. I do appreciate the schooling on confined space safety. It is scary thinking about inhaling lungs full of nasty gasses. So, no issues of getting zapped with a plasma when cutting inside a vessel... There is consensus there, I take it...
Reply:Shouldn't be. As long as you're not the ground path.
Reply:Originally Posted by DSWHowever your original question shows you have a poor grasp of some basic principals.
Reply:Not sure where that came from. Maybe someone else will chime in. We are talking about electricity, so equipment condition must be maintained. You don't necessarily need to be afraid of it [electricity] so much in this day and age, but you better have a very good respect for it. I keep my hands on the torch for better control (I seem to wobble a bit in my old age).Larger pieces or longer lengths, I cross clamp the drop to control it if possible as I don't have a cutting table (no room).I generally have the same PPE on for plasma cutting as I do for stick welding (don't like frying the "greens" if the cut doesn't go right).
Reply:All things considered, for just two pipes, why not use a Sawsall?
Reply:What bothers me most is that your asking questions here on an online blog and by the sounds of it your employer hasn't covered all angles correctly for this type of work. Scary, to say the least!JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:Wow... I'll just look for answers online instead of asking them at this place. What a crotchety bunch of old men. -Why don't I use a sawzall? Because I don't want to. There's no room.-If I cared for Welding Web any longer I'd post some links I found on plasma cutting safety that backs up what I was talking about.-I don't have an "employer". But thanks for you great concern.
Reply:Originally Posted by MoltenMetalNothing but a limited amount of wood tar in the pipes and the tank. The two minutes figures getting in, cutting off two 2" sch-40 pipes and climbing out. The bottom of the tank has a good sized hatch and the entry is large enough to climb through. I'll have good ventilation from top to bottom and out. I do appreciate the schooling on confined space safety. It is scary thinking about inhaling lungs full of nasty gasses. So, no issues of getting zapped with a plasma when cutting inside a vessel... There is consensus there, I take it...
Reply:Sorry, the OP posted again while I was researching "wood tar" and writing my reply so I missed that he was a contractor and not an 'employee'.  I hope he is able to complete his own research into how to best approach the task at hand safely.- MondoMember, AWSLincoln ProMIG 140Lincoln AC TombstoneCraftsman Lathe 12 x 24 c1935Atlas MFC Horizontal MillCraftsman Commercial Lathe 12 x 36 c1970- - - I'll just keep on keepin' on.
Reply:From reading this thread "crotchey old men = people more concerned for the OP's well being then he is. Just my 2 cents.
Reply:At the industrial plant I work in, If i even broke the plane of entry on a tank without having it sniff tested, without having a pre entry meeting with a confined space entry team and without all the related equipment being locked out and tagged out, I would be fired on the spot. Without question.Safety first young man. It's your life your playing with, not mine.If an outside contractor did this in our plant, they would be escorted off the property and another contractor would be brought in to do the job and the correct confined space entry rules and procedures would be followed the second time.Last edited by snoeproe; 11-26-2012 at 07:41 PM.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:Originally Posted by snoeproeAt the industrial plant I work in, If i even broke the plane of entry on a tank without having it sniff tested, without having a pre entry meeting with a confined space entry team and without all the related equipment being locked out and tagged out, I would be fired on the spot. Without question.Safety first young man. It's your life your playing with, not mine.If an outside contractor did this in our plant, they would be escorted off the property and another contractor would be brought in to do the job and the correct confined space entry rules and procedures would be followed the second time.
Reply:One of the most important life skills is knowing when it's okay to play fast and loose with safety, and when it's not. Sometimes I drive my tractor with the seat belt off and the ROPS up. Sometimes I weld in flip-flops. But I never point a gun at myself.Sounds like the OP and the rest of the thread have a difference of opinion on which category this situation falls into.It's no fun when people tell you you're doing something dumb! Crotchety old men? maybe some are but heed their warnings and be safe.Miller diversion 165Miller mig 211Hypertherm pm 30Milwaukee 6230 14 inch chop sawMd 45 mag drill (RIP; fell on its head)New MD 45! Thanks to the esposa!Finally got an O/A setup
Reply:Molten Metal. In case you're still looking.I dug out the manual for my Powercut 875. You are correct about using the rubber mat (insulator).  Presuming it's pure and has no carbon content as not all "rubber" is non-conductive (ask a Lineman). The first notice in the electrical safety section, strictly enforced, would eliminate using it in a confined space. The grounding procedures include grounding the equipment (work piece). If it has any heavy elctrical devices (motors, etc.) it should be sufficiently grounded already for your described piece of equipment (plasma). If it has LV sensors you need to discuss your procedure with the electrician so you don't fry those devices by grounding through or inducing HF into those. Some of those devices and their control circuits run into the several thousands of dollars to replace just the parts + labor.Have the electrician verify!My apologies to you if I (we) seem crotchety. Old.......... ? You have live long enough to earn that title.