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Hello guys and gals. Our pressure washing company recently purchased a boiler for high pressure hot water applications. I was inspecting the unit when I noticed two questionable places in the boiler pipe. This unis is essentially a schedule 80 1/2" id steel pipe coil with the burner heating it up while 4000 psi water travels through it. So the pipe is a subject to 4000 (up to 6000 psi) 250 degree water.My question regarding this pipe, is it even legal to run something like this under the pressure? Are pressure pipes suppose to be inspected? What are the legal tolerance on undercut on a pressure vessel? Area of concern are those two tack places. One is gouged out and other near melted through the pipe itself (looks like wall of the pipe caved in).Would like to hear your opinions on this weld/tack job. Appreciate your input!!
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Last edited by MichaelA2014; 6 Days Ago at 10:17 AM.
Reply:Was the unit bought used? Do you know how thick that pipe is? Could you post more information about the unit's make and model, and some pictures showing the entire unit, so we have better perspective?Sorry, I don't know anything about codes that would cover such equipment, but assume others here do, and will comment on that aspect.
Reply:
Originally Posted by Oldiron2
Was the unit bought used? Do you know how thick that pipe is? Could you post more information about the unit's make and model, and some pictures showing the entire unit, so we have better perspective?Sorry, I don't know anything about codes that would cover such equipment, but assume others here do, and will comment on that aspect.
Reply:So the heater is actually on the high pressure side?
Reply:yes. the pressure pump has a seals that are not able to withstand the heat so you have to pressurize the water first them heat it up.
Reply:
Originally Posted by MichaelA2014
It's a schedule 80 pipe in 1/2" ID. These pictures are taken through the exhaust of the unit and are not immediately visible without looking through the exhaust and using macro to get to the pipe. And this IS a brand new unit thus the question about acceptable undercut. Wouldn't even look at this if it was a used and tested rig.
Reply:I guess you need pressure to get 250 degrees, too.
Reply:
Originally Posted by MichaelA2014
It's a schedule 80 pipe in 1/2" ID. These pictures are taken through the exhaust of the unit and are not immediately visible without looking through the exhaust and using macro to get to the pipe. And this IS a brand new unit thus the question about acceptable undercut. Wouldn't even look at this if it was a used and tested rig.
Reply:I welded up a couple of those over the years, clean well and 3/32 7018 back then, might even use wire today if I could reach it. Put a dab on first so you dont blow a hole in it and dont get greedy.. I repaired holes from those factory tack welds. Exact same issue. Alkota coils. I built several units for trucks. This is not really a boiler, its a burner coil for heating water.
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Last edited by Sberry; 5 Days Ago at 08:49 AM.www.urkafarms.com
Reply:
Originally Posted by Sberry
I welded up a couple of those over the years, clean well and 3/32 7018 back then, might even use wire today if I could reach it. Put a dab on first so you dont blow a hole in it and dont get greedy.. I repaired holes from those factory tack welds. Exact same issue. Alkota coils. I built several units for trucks. This is not really a boiler, its a burner coil for heating water.
Reply:
Originally Posted by tapwelder
I guess you need pressure to get 250 degrees, too.
Reply:I understand not taking it apart. Do you regularly make steam or hot wash? While all the pressure is hi the volume is really small. I am jot sure what code it might fall under but I got no problem fixing that and if it's really bad it ain't going to get better. Easier to fix it before it's well used. This isn't a new problem, ain't the first one. They can be sloppy when they think u can't see. Yes it passed pressure test but it's crap.www.urkafarms.com
Reply:
Originally Posted by 12V71
If it is indeed a new unit, take it up with the manufacturer as a warranty issue.
Reply:Is this consider a closed steam vessel ? Is there a ASME stamp or nameplate on the vessel ? We've done work on ASME boilers. Anyone welding on them is ASME code certified and sometimes a welding code inspector viewed worked and even did x-rays. I've done enough of high pressure steam work and learned as an apprentice to respect it. I don't know how high pressure steam pressure washers are rated. I would contact supplier and request documented paperwork that this is designed and tested. Regardless of what they say, I would not do any welding on that at all.Last edited by BD1; 5 Days Ago at 04:55 PM.
Reply:
Originally Posted by MichaelA2014
Thank you for the input. I can tig it up but I don't think I need to take the unit apart. We paid full retail price for the top of the line hot box. I shouldn't have to take it apart and fix it before it even been turned on. The quality control is null. Plus to take it apart I will have to cut the stainless coil wrap and possibly tear off kaowool to inspect the rest of the coil and this isn't something I am willing to do. We are in the pressure washing business and not a coil repair one
The question remains, is this damage within tolerance of ASME standards or not for the half inch schedule 80 pipe working under 4-5000 psi at 250 Degree water.
Reply:First of all its a heated pressure washer not a boiler. It doesnt need to be inspected its water not steam! 6000 psi isnt **** we run that in schedule 40 pipe in hydraulic systems. Water unlike steam, air, ect is incompressible therefore it doesnt store energy like gas does (basically a spring) so if/when that coil blows it wont be any different then a hydraulic line busting (actually better there wont be any oil to clean up). Id leave it alone if it blows and starts leaking then fix it.
Reply:The spot with the torn out tack is probably below the corrosion allowance for steel pressure pipe so I would recommend you tig that up if you're able. The others I wouldn't worry about.
Reply:
Originally Posted by Oldiron2
I agree with 12V71. Even if it somehow isn't a code violation, it goes against all the standards I've ever seen in good welding books and isn't the quality one should expect for a new piece of equipment so should be dealt with under warranty. If it is a violation, that's even worse so the company should be pleased you caught the problem before using it.
Reply:325 degrees and no one suggested it gets done with a coat hanger. I will agree its probably within the allowance and in that area its not likely to be a problem. I would likely fix it but am confident in the ability. While this is under pressure and heat its not quite the same as a vessel. If it can be blown up it wont have a thing to do with that weld. We didnt have net when I was working on these regular but I have repaired leaks in them. When I do I treat it dssurgically due to the azzhole spots they can be in and its kind of a 1 shot fix if you cant get at it. As for the net, as I mention we didnt have it so I never researched the risk but I aint the only one that keep a whole fleet of them running. I never heard of one blowing up but shate goes wrong with them all the time and are operator sensitive. I have never made steam with mine and am on the original coils and still works well, bought in 84 new. There is no inspection date required, most are operated with minimal training really and human error is the main concern, I bout overheated my build a could times for I figured out a couple things I miss due to human error, miswire a switch I have done a hundred times etc. I remember 1 where they worry up a storm and have the local vessel shop try it, guy sticks a rod in and burns a hole. Turns out, no one has one even at some astronomical price, guy was pissed I charge 8 for fixing it for a 30 second weld. I made a big deal out of it took it out of the truck, thought they might replace it and was hoping for the core. At the time the bill was 600 or so and got,,, the last guy only charged 75,,,, didnt grasp that it didnt work. You would think a guy would be grateful, I forget what it cost then but million btu burner and put it back to work when it was booked solid.Last edited by Sberry; 3 Days Ago at 11:25 AM.www.urkafarms.com
Reply:I think I might fix that popped tack and not sure I would connect it. Easy now, a mess when it leaks. A thing to remember this is shielded when in operation, a failure is going to be a leak. Not the same as a whole vessel where the containment and shell is under pressure and can rocket up exponentially. I was off and on oilpatch for a decades, vessel has a stamp, must be serviced with code but they let monkeys work on the pipe. Lots of 2 inch.www.urkafarms.com
Reply:These heated pressure washer coils are in a covered sheetmetal can so to speak. As others have said, it will just probably spring a leak and not explode. There is a real old youtube vid of an employee of the "coil" company welding these together and by the looks of it, these are not x-rayed or have to pass any regulations.www.tjsperformance.comDynasty 300 DXHTP 240HTP Microcut 380Hyperthem 85JD2 Hyd Bender and HF Hyd Ring Roller all in one =(Frankenbender)Bpt. Mill/DRO4' x 8' CNC Plasma TableInstagram: tjsperformanceYT: TJS Welding and Fabrication
Reply:We use 1 machine to pressure test the other after a repair. I think I have even see coil stock simply mig welded together and continue on.Last edited by Sberry; 3 Days Ago at 11:56 AM.www.urkafarms.com
Reply:I read the op again, they are pressure washing and not steaming. In either case the hose is the weak link. The hot and cold cycling loosens the fittings, sometimes I simply use reusable ends. Can really get them tight and last as good as crimps. We call these steamer trucks and steamer service but most are hi pressure hot water at 200 degrees. They can be used as injection trucks also, for fresh water, light brine and even methanol or can heat antifreeze. They can have antifreeze cycled thru them for cold weather, I have a fire pump on my truck also and while I dont keep it shop heated stored I have electric in insulated box at 45 all winter. When they are used daily they ideally go in to insulated building, meant for working in cold weather, thawing, injecting and even cold weather washing. I wash a car about every day in the winter, a couple isnt out of the question and some after every trip to main road salt bath. Its kind of hard on the paint but cant have them white coated with salt either.Last edited by Sberry; 3 Days Ago at 12:05 PM.www.urkafarms.com
Reply:Cleaning lady just did her own,,, training still needed and restricted to cold,,, ha, left it running.www.urkafarms.com
Reply:Before it was a local fire hall I chop a hole in the parking lot outside the door and feed thru a 2 inch tap indoors with ball valve for filling steamers. The local FD now uses it. The originals were using a rigged rod to city water valve to fill trucks outside was really primitive. I recall now, even t it so it could go back out thru the wall and add thru wall handle, warm tap could use inside or out. Can fill a truck, 500 to 900 gals in 5 minutes. I have a good well, 30 gal+ and fill in 15 if its not right empty. There are a lot of things can be done with hot wash. Its not cheap to operate, 15$ an hr for fuel on hot but does a lot of work. Cold is good for dirt and rinse but so many uses for hot with grease, grime, paint prep, salt cleaning and de ice in the winter. I am not sure how they rate some of the machines and would like to see guages on them. My machines are for cleaning, the one in the truck was originally for a paint contr for cleaning houses and equipment. I use 1400 or bit less on truck and have my shop at 1500, but 4 gpm and 5 in the shop, made for grime removal.Last edited by Sberry; 3 Days Ago at 12:24 PM.www.urkafarms.comOilfield we had 2000 and no conventional unloader, simple bypass so they could be ran up and inject against pressure, washed at about 1800 tops, very most and had pressure relief at 3K maybe. Outfit I did work for started with small trucks, big tank, cobbled together all jammed in and just crushed the small trucks. 450 wasnt much better incl box and I finally had them go to 600 class and we put 2 bigger tanks in them which was good on occasion, I put big saddle fuel tank on them for off road burner fuel. Then we change burners and pumps to 11gpm and million btu, they would run 2 guns for cleaning and the proto had that but then didnt use it. We found the laziest operators and they found the easiest way to make the most money and could sit and wait no problem. The bigger units were so much hotter and so much more they tool some small injection work from hot oilers, was a lot cheaper, faster and handier. I wish I had some pics but this was before the net.Last edited by Sberry; 3 Days Ago at 12:33 PM.www.urkafarms.com
Reply:
Originally Posted by Sberry
I think I might fix that popped tack and not sure I would connect it. Easy now, a mess when it leaks. A thing to remember this is shielded when in operation, a failure is going to be a leak. Not the same as a whole vessel where the containment and shell is under pressure and can rocket up exponentially. I was off and on oilpatch for a decades, vessel has a stamp, must be serviced with code but they let monkeys work on the pipe. Lots of 2 inch.
Reply:
Originally Posted by MichaelA2014
It's not a popped up tack. It looks like one but it isn't. Thats a gouged out metal from sloppy mig operator.
Reply:
Originally Posted by 426hemi
First of all its a heated pressure washer not a boiler. It doesnt need to be inspected its water not steam! 6000 psi isnt **** we run that in schedule 40 pipe in hydraulic systems. Water unlike steam, air, ect is incompressible therefore it doesnt store energy like gas does (basically a spring) so if/when that coil blows it wont be any different then a hydraulic line busting (actually better there wont be any oil to clean up). Id leave it alone if it blows and starts leaking then fix it.
Reply:A 1/2 coil is in the 5 gpm range, depending on how hot and how much coil and how big the burner but there should be a tstat at 200 or so and on some units (have built these from pile of parts) can regulate the flow to change temp. My own is factory designed and matched unit and is near 200 running continuous, burner does not cycle which is just right. As I mention have built larger ones but,,, can regulate the flow/pressure just fine but the burner cycles when washing with conventional wand. One of the guys figured out to connect a brass garden nozzle to it and really let the water thru and create flood of hot for melting and even rinsing oil down.www.urkafarms.com
Reply:They run so long we use liq cooled engines in them, seems I see one just 4 yrs maybe less and 6K on the clock.n The engines were Kaws like in thise Deere garden tractors but they sit inside a cozy box and no dirty air, run constant, start warm and lasted a LONG time. After I leave my bud said they7 try some Honda but they didnt hold up.www.urkafarms.com
Reply: Really ? So you don't care if it blows and injury's a worker ??
Reply:I remember looking at a replacement in a crisis and the model was in it they hadnt even made replacement coil for, didnt have it in stock and said they had itr scheduled to run 6 in next 2 months. Was still running 20 yrs I knew of after we fix a leak and return ity to service the same day.www.urkafarms.com |
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发表于 2022-9-16 15:52:11