Compressor dropped during move, now junk?
- Thread starter davejo
- Start date
When I bought an IR compressor (tank made by Manchester), I searched for a petroleum/refinery/chemical plant engineering company who had an ultra sonic thickness tester. I made an appointment, stripped the compressor, put the tank in my truck, with the bottom end toward the tailgate, and two engineers from the company met me outside in their parking lot, with tester and pads in hand. They were so impressed that I'd take the trouble to do this, they didn't even charge me. Their typical customers are Dow Chemical, Tesoro, Chevron, Shell, etc.
It was an eye opening experience. I already knew the tank had to be thinner than when originally made, but it was interesting to see how much thinner, and how uneven and spotty the thinned out places were. This was all on the bottom bell of the vertical tank. I was relieved that even the thinnest portion was still within the minimum thickness specified for the pressure rating of the tank, but it was certainly below the material thickness the bell was originally formed with.
I paid for the National Board Certification report for my tank to get all the particulars. I see that the OP's tank has a National Board Certification ID. Therefore, there is a similar detailed report on file with the National Board on the original specifications of the tank, that provides a little more detail than what is stamped on the label welded to the tank.
My tank was made in 2000, and your (the OP's) tank was made 10 years earlier, in 1990. That is 10 more years of exposure to a water condensating corrosive environment. That alone is reason enough to arrange an ultrasonic thickness test for the tank, to detect how much thickness was washed away with the drain water due to corrosion. While they are at it, a thickness measurement can be made of the deep gouge put in the tank from moving it.
If I had any doubts about the importance of testing the tank before putting it in service, I'd watch that video posted above a couple more times, and the several more like it, where people actually died. The gas station / car wash video of the 80 gallon vertical explosion is particularly chilling. These are all ASME code welded tanks btw, including the small red tank in the video link posted above.
Last edited:
rburke65
Well-known member
I'd weld it and use it. Thanks Hawkeyes for that price....always wondered how much.
Off-Street Parking
Well-known member
Attachments
12ozd
Well-known member
^ I actually thought of that when I posted.
Classic.
Classic.
bigredmf
Well-known member
I purchased a Chicago a Pneumatic 5 hp 80 g compressor from a local compressor company.
It has several similar scratches on the tank.
CP sells their freight damaged compressors to compressor distributors for resale.
If they are comfortable with these making it to market why should you be concerned?
Red
Sent from my iPad using Tapatalk
It has several similar scratches on the tank.
CP sells their freight damaged compressors to compressor distributors for resale.
If they are comfortable with these making it to market why should you be concerned?
Red
Sent from my iPad using Tapatalk
Original Guster
Active member
- Joined
- May 7, 2012
- Messages
- 32
The paint looks worse than the steel. Clean it up and really give it a good visual inspection. See it it will polish out with some 220 paper if it bothers you. The cylinders are made on a roll in a shop- they get handled with cranes and forklifts, not padded gloves. They are not perfect when they are made. If it bothers you that much find a code welder to look at it. The tank can be welded and x-rayed.
Before I found GJ I wouldn't have given that damage a second thought but maybe I'm learning as I go. The responses here have far exceeded my expectations and have expanded my knowledge. The Monty Python reference is icing on the cake.
I have had no luck finding a place to get my tank looked at. I will try the fire safety business in town today. I could also pull the big plugs off the side to see how much rust is in there with an endoscope. What sort of businesses do the ultrasonic exams and where would somebody qualified to weld a tank be found at?
I have a dial indicator so maybe I can measure the depth of the scratch....
I have had no luck finding a place to get my tank looked at. I will try the fire safety business in town today. I could also pull the big plugs off the side to see how much rust is in there with an endoscope. What sort of businesses do the ultrasonic exams and where would somebody qualified to weld a tank be found at?
I have a dial indicator so maybe I can measure the depth of the scratch....
You can get an entire compressor wit an 80 gal tank for $7-800 brand new, put your pump and motor on it and sell the rest. I am not sure what they are going to charge you to weld and xray that tank but Ill bet it will make buying a new tank look attractive..
Yes you are probably right about the costs of diagnosing the tank properly exceeding the cost of a new one but I 'll keep digging.
I found an IR 7.5hp that needs a motor for $500 so I'll check that one out locally. Home depot has a new 80 gallon for 850 sitting on the floor and it has a ASME plate on it, maybe all 80 gallon tanks do?
One thought was to buy a cheap 80 gallon unit and plumb my current pump into it to give me extra capacity with two pump heads. More to learn...
I found an IR 7.5hp that needs a motor for $500 so I'll check that one out locally. Home depot has a new 80 gallon for 850 sitting on the floor and it has a ASME plate on it, maybe all 80 gallon tanks do?
One thought was to buy a cheap 80 gallon unit and plumb my current pump into it to give me extra capacity with two pump heads. More to learn...
galute
Well-known member
I do hydro testing as part of my job. I would fail that tank on a visual and would not allow it to even be tested on my job site. You will not find anyone qualified to test it that will touch it.
Fordguy1964
Well-known member
Thanks for the eye opening lesson guys. I am now in the market for a new compressor!
AnthonyJ124
Well-known member
Lots of opinions here...
If it makes you feel ANY better, I had a 15 year old 40 gallon 5hp MAC compressor that made an unexpected trip down a few stairs due to a wet boots and failure to plan situation... Granted that may be more extreme than your situation, but the tank on mine didn't scratch like yours and took the brunt of the drop on a dome end (and didn't dent). I scrapped the compressor and moved on. The hit to my ego and having to explain to my wife that I needed to buy a new compressor was the lesser evil vs the potential of a leak or blowout...
I used to work with a guy that always said "if you have to question it, get rid of it" usually followed by a comment about X being cheaper than people. That mentality certainly caused additional expense and probably some time waste, but it did ensure a level of safety on his site.
If it makes you feel ANY better, I had a 15 year old 40 gallon 5hp MAC compressor that made an unexpected trip down a few stairs due to a wet boots and failure to plan situation... Granted that may be more extreme than your situation, but the tank on mine didn't scratch like yours and took the brunt of the drop on a dome end (and didn't dent). I scrapped the compressor and moved on. The hit to my ego and having to explain to my wife that I needed to buy a new compressor was the lesser evil vs the potential of a leak or blowout...
I used to work with a guy that always said "if you have to question it, get rid of it" usually followed by a comment about X being cheaper than people. That mentality certainly caused additional expense and probably some time waste, but it did ensure a level of safety on his site.
kylefitz
Well-known member
Just put that sticker I've the gouge. Problem solved.
dodgejunkie
Well-known member
- Joined
- Nov 7, 2014
- Messages
- 198
You must not hydro any old fire or water tube boilers then! I've seen worse pass a hydro all the time! And before you question, I'm a R stamp carrying welder, and have been for years!
There's probably rusted areas on the inside of the tank that look worse than that minor scratch.
Imagine how often these compressor tanks are moved, dropped, run into with things ( like forklifts) hammered on and used as anvils, you'd expect a compressor tank failure in the news every day.
Imagine how often these compressor tanks are moved, dropped, run into with things ( like forklifts) hammered on and used as anvils, you'd expect a compressor tank failure in the news every day.
pstnbly
Well-known member
DO NOT WELD ON ANY CERTIFIED PRESSURE VESSEL!
Especially where that scrape is. The tank is scrap IMO.dodgejunkie
Well-known member
- Joined
- Nov 7, 2014
- Messages
- 198
DO NOT WELD ON ANY CERTIFIED PRESSURE VESSEL!
There are literally thousands of boilers that have had the tubes welded in the tube sheet after the rolled seal failed to hold the pressure, and all of them are certified pressure vessels. Every one that I have welded on have been in excess of 125 psi! So, welding on a pressure vessel is NOT uncommon at all.
BTW when we certify a vessel after welding, it is pressurized to twice the normal operating pressure! That is standard for certification.
Last edited:
PugetDude
ALLIANCE MEMBER
Surprised no one suggested doing your own hydrotest...
All you need are a water source, a few fittings, a gauge, and another compressor.
All you need are a water source, a few fittings, a gauge, and another compressor.
Professur
Well-known member
If you can't find someone to hydrotest that, you must not know where to look. Anywhere that fills propane tanks will have a test guy, if they don't do their own testing. Or the local welding gas supply. Or the local Hospital gas supply. I get my testing done by the guy that fills the CO2 bottles for local restaurants .. who also just happens to fill my CO2 welding gas bottle.
Professional hydrotesting involves a visual inspection as well as tanking the pressure vessel. Frankly, i'd be very surprised to see a scratch like that even see the tank. It might well pass hydro today .. but it's a weak spot. 500 cycles of pressure and that's where a crack will start. A professional welder might be up for thickening the metal over it, and even be willing to recertify it ... but for the cost of that, a new tank is the smarter choice. Cut it in two and make a BBQ out of it to recoup some of the new tank's cost.
Professional hydrotesting involves a visual inspection as well as tanking the pressure vessel. Frankly, i'd be very surprised to see a scratch like that even see the tank. It might well pass hydro today .. but it's a weak spot. 500 cycles of pressure and that's where a crack will start. A professional welder might be up for thickening the metal over it, and even be willing to recertify it ... but for the cost of that, a new tank is the smarter choice. Cut it in two and make a BBQ out of it to recoup some of the new tank's cost.
nehog
Well-known member
I doubt his compressor will deliver 3x the test pressure. I doubt he has the skills to test it. I'm sure you don't know what you are saying since you'd not test with a compressor, you'd test with a hydraulic pump pushing water.
A compressor compresses gas (air), and that can't be used to test a tank (or any other similar device.)
OP: just take it to be tested.
bigredmf
Well-known member
Hydro test
Fill tank with water.
Add a tee with a gauge.
Hook up grease pump and pump up to your desired proof pressure.
Move on!
Red
Sent from my iPad using Tapatalk
Fill tank with water.
Add a tee with a gauge.
Hook up grease pump and pump up to your desired proof pressure.
Move on!
Red
Sent from my iPad using Tapatalk
LS6 Tommy
Well-known member
No disrespect intended, but that's not even close to how hydrotesting is done. There is no compressed gas of any kind invlolved. It's not a very safe idea.
Tommy
galute
Well-known member
You're comparing a compressor tank to boiler tubes. Seriously?
dodgejunkie
Well-known member
- Joined
- Nov 7, 2014
- Messages
- 198
Yes seriously! A pressure vessel is a pressure vessel. Probably ought to read the ASME code before commenting! Both regulated the same in most states too. Is 125 psi different where you're from?
welder4956
Well-known member
Cool. What is your R Stamp number?
dodgejunkie
Well-known member
- Joined
- Nov 7, 2014
- Messages
- 198
Yeah, I'm not going to post that on a message board but, thanks for asking!
If the gouge is below the minimum allowable wall thickness, it can be welded by a certified welder and hydro tested (1.5X MAWP). If the minimum wall thickness is maintained (as measured with an ultrasonic instrument), the gouge can be feathered to eliminate the stress risers.
Mooky
National Board Certified Inspector PA/DE
AWS Certified Welding Inspector
API 570
Shop in Winchester VA: http://www.winctool.com/index.php/2013-03-14-18-15-36/production-fabrication
Inspection, repair & certification will likely exceed the cost of a replacement tank. I've repaired much worse than that in the petrochemical industry, but small tanks like that are typically scrapped due to the cost.
Mooky
National Board Certified Inspector PA/DE
AWS Certified Welding Inspector
API 570
Shop in Winchester VA: http://www.winctool.com/index.php/2013-03-14-18-15-36/production-fabrication
Inspection, repair & certification will likely exceed the cost of a replacement tank. I've repaired much worse than that in the petrochemical industry, but small tanks like that are typically scrapped due to the cost.
Last edited:
welder4956
Well-known member
I was surprised at how many suggested the OP just "weld it up" or use it as-is. I get to do failure analysis and root cause evaluations in my current job and see this attitude occasionally. This attitude typically precedes an accident where someone is seriously injured. It is easy to sit back and suggest such actions when the consequences will be to the OP or his family or property and not to the poster.
These compressor tanks are very thin wall and do not tolerate defects well. Just striking an arc on the tank will result in the bead melting thru to the inside surface. So if there is any porosity in the start or a crater on the stop of the bead, then the weld defect would be worse than leaving the gouge as-is.
You could hydro test with water as some have suggested. The required test pressure is 150% of design pressure or MAWP. If you go any higher, you risk exceeding 90% of the yield strength of the material unless you actually know the material specification and grade, and the current thickness of the tank and can calculate the maximum test pressure allowed. The 90% limit comes from the ASME code the tank was designed and manufactured to meet.
You could also go to a R-stamp holder as others have suggested, but this would require a ultrasonic thickness measurements of the tank to determine if the original design is still met. But since you don't have the original design calculations, an engineer will need to calculate the minimum required wall thickness and determine if the measured wall thickness is acceptable. Then the R-Stamp holder's third party Authorized Inspector will need to review and accept before he will sign off on a R-1 form for the repair. So, this route is going to wind up exceeding the cost of a new tank real quick unless someone offers to do it for free.
Personally, I would not risk life or property over a damaged tank. Just buy a new tank and you won't have to worry about it. Be safe.
These compressor tanks are very thin wall and do not tolerate defects well. Just striking an arc on the tank will result in the bead melting thru to the inside surface. So if there is any porosity in the start or a crater on the stop of the bead, then the weld defect would be worse than leaving the gouge as-is.
You could hydro test with water as some have suggested. The required test pressure is 150% of design pressure or MAWP. If you go any higher, you risk exceeding 90% of the yield strength of the material unless you actually know the material specification and grade, and the current thickness of the tank and can calculate the maximum test pressure allowed. The 90% limit comes from the ASME code the tank was designed and manufactured to meet.
You could also go to a R-stamp holder as others have suggested, but this would require a ultrasonic thickness measurements of the tank to determine if the original design is still met. But since you don't have the original design calculations, an engineer will need to calculate the minimum required wall thickness and determine if the measured wall thickness is acceptable. Then the R-Stamp holder's third party Authorized Inspector will need to review and accept before he will sign off on a R-1 form for the repair. So, this route is going to wind up exceeding the cost of a new tank real quick unless someone offers to do it for free.
Personally, I would not risk life or property over a damaged tank. Just buy a new tank and you won't have to worry about it. Be safe.
welder4956
Well-known member
That's OK. Mine is R-1906.
dodgejunkie
Well-known member
- Joined
- Nov 7, 2014
- Messages
- 198
That's great! Is that yours, your companies, or the company you work for?
Which section would you have him read? Section I and III are for fired pressure vessels (covering your boilers) or Section VIII for unfired pressure vessels (i.e., a compressor tank)? Not at all the same requirements.
Installation requirements for big industrial boilers are different than for pressure vessels exposed to the general public. A utility class boiler tube weld failure isn't going to do a damn thing outside the boiler casing, the people around the boiler are wearing PPE, and workers know they are in an area with high pressure equipment.
A far smaller boiler in a home, school, or office building has completely different installation requirements, even tho the PV Codes for the boilers' constructions may be the same.
Last edited:
PugetDude
ALLIANCE MEMBER
Started my career working in an ASME Section 8 Pressure Vessel Shop... I might know a little about hydrostatic testing.
ASME:
http://mtm-inc.com/reduce_project_risk/asme_code_section_viii_pressure_tests/
Wikepedia:
Hydrostatic tests are conducted under the constraints of either the industry's or the customer's specifications, or may be required by law. The vessel is filled with a nearly incompressible liquid - usually water or oil - pressurized to test pressure, and examined for leaks or permanent changes in shape. Red or fluorescent dyes may be added to the water to make leaks easier to see. The test pressure is always considerably higher than the operating pressure to give a factor of safety. This factor of safety is typically 166.66%, 143% or 150% of the designed working pressure, depending on the regulations that apply.
Thanks for the great info. I guess I was asking the wrong questions of the "air compressor service and repair" shops that I called saying they couldn't help me.
The last time I walked through Home Depot, my daughter suggested that we need a new bbq grill. More writing on the wall, perhaps.
LS6 Tommy
Well-known member
Started my career working in an ASME Section 8 Pressure Vessel Shop... I might know a little about hydrostatic testing.
ASME:
http://mtm-inc.com/reduce_project_risk/asme_code_section_viii_pressure_tests/
Wikepedia:
Hydrostatic tests are conducted under the constraints of either the industry's or the customer's specifications, or may be required by law. The vessel is filled with a nearly incompressible liquid - usually water or oil - pressurized to test pressure, and examined for leaks or permanent changes in shape. Red or fluorescent dyes may be added to the water to make leaks easier to see. The test pressure is always considerably higher than the operating pressure to give a factor of safety. This factor of safety is typically 166.66%, 143% or 150% of the designed working pressure, depending on the regulations that apply.
I'm not arguing your background. I put next to no faith in wikipedia, but even there, NOWHERE does it say a compressed gas is used. I'm sure you're very well versed in the codes that apply to Sec 8. IIRC, Sec 8 is BPVC, correct? I do know there are different types of hydro testing used for boilers than other pressure vessels.
I've had many boilers hydro'd over the years. It's a completely different test than what a high pressure vessel goes through, at least with typical water tube and fire tube boilers running under 15 Psig. I've also had numerous gas cylinders, refrigerant vessels, fire supression system cylinders and SCUBA tanks recertified. There is no air or gas used, period. The vessel being tested is filled with a fluid and all the air is carefully purged. The FLUID the vessel being tested with is pressurised. The vessel being pressurized is also sealed in a water filled tank. The test tank is also carefully purged of all air.
The differences in testing precedures are dictated by the vessel pressure test ratings. That being said, let's just say we shouldn't make blanket statements about the test procedures.
Tommy
Last edited:
Professur
Well-known member
The testing my tank goes through is pretty simple. All the holes save one are plugged. The tank is dunked in the testing tank and filled with water. The last hole is filled with the pressure filler thingy. Then the testing tank is zeroed out on it's gauge. Then the pressure is applied and the testing tank gauge is watched for movement. The amount the water level raises shows how much the tested tank has stretched under pressure.
LS6 Tommy
Well-known member
Very similar to what I've witnessed. The testing tank has burettes to measure water displaced by the stretch of the vessel being tested.
Tommy
kaymccampbell
Well-known member
This is a no brainer.
Get some paint. Contrasting, if possible.
Paint:
SHOULD HAVE RESTRAINED THIS LOAD
On the side of it.
Then cut it up so you can read the words forever and make a nice baby smoker.
Then go get a new tank.
Here endeth the lesson...
Get some paint. Contrasting, if possible.
Paint:
SHOULD HAVE RESTRAINED THIS LOAD
On the side of it.
Then cut it up so you can read the words forever and make a nice baby smoker.
Then go get a new tank.
Here endeth the lesson...
52wrench
Well-known member
Not worth the brain cells to even consider repairing it. Cut it up, consider it a learning experience. How many would just weld up a grinder gouge on a bottle of O2 or Ar? Different ball park but the possible outcome is the same.