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How to treat the testing water for winter temperatures 1
- Thread starter aironyx
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gr2vessels
Mechanical
aironyx,
A 60% Ethylene Glycol solution frezes at -55 deg C, hence is relatively safe at -40 deg C (if is not turning in a slush).
A 60% Ethylene Glycol solution frezes at -55 deg C, hence is relatively safe at -40 deg C (if is not turning in a slush).
- Thread starter
- #3
Look at the temperature of the test. -40C is pretty cold. I wouldn't want anyone trying a test that cold as there are two things that can happen:
1) Inspectors are too cold to do a thorough inspection - probably will happen,
2) Chance of brittle fracture - may or may not be likely, chances go up as the temperature goes down.
My 2 cents only.
EJL
1) Inspectors are too cold to do a thorough inspection - probably will happen,
2) Chance of brittle fracture - may or may not be likely, chances go up as the temperature goes down.
My 2 cents only.
EJL
This runs along the same lines. I do not know where in the world are you but here it rules:
<<A good friend will bail you out of jail, but a true friend
will be sitting beside you saying ” Damn that was fun!” - Unknown>>
<<A good friend will bail you out of jail, but a true friend
will be sitting beside you saying ” Damn that was fun!” - Unknown>>
- Thread starter
- #8
I'm in Kazakhstan and i have to hydrotest piping and not tanks of vessels.
Is there any ASME code that don't allow me to test with use of antifreeze (ethylene glycol or equivalent)?
Piping materialhas been chosen to work in those ambient temperature, so I'm not really worried about this, but if you have any better suggestion, please write to me, thanks
Is there any ASME code that don't allow me to test with use of antifreeze (ethylene glycol or equivalent)?
Piping materialhas been chosen to work in those ambient temperature, so I'm not really worried about this, but if you have any better suggestion, please write to me, thanks
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1
- #9
aironyx,
The Code allows the use of antifreeze in test water. What you should be concerned about are disposal or spill contingency plans. Check with the Ministry of Environmental Protection in Kazakhstan for regulations. I'm pretty sure they have a limit on the amount of glycol/water mixture that can be disposed on land or water. I suggest you hire a contractor that specializes in the supply, recovery after testing, and recycling of antifreeze-water mixtures.
Have a look at this document if you can get some ideas...
The Code allows the use of antifreeze in test water. What you should be concerned about are disposal or spill contingency plans. Check with the Ministry of Environmental Protection in Kazakhstan for regulations. I'm pretty sure they have a limit on the amount of glycol/water mixture that can be disposed on land or water. I suggest you hire a contractor that specializes in the supply, recovery after testing, and recycling of antifreeze-water mixtures.
Have a look at this document if you can get some ideas...
gr2vessels
Mechanical
aironyx,
No, there is no ASME Code preventing you to use of most suitable hydrotesting medium, except the service conditions and then only if you will be left with unwanted residues in your piping.
The testing requirements I believe are clear to you and are detailed in the B31.1, Clause 137.1.2 Temperature of Test Medium.
"The temperature of the test medium shall be that of the available source unless otherwise specified by the Owner. The test pressure shall not be applied until the system and
the pressurizing medium are approximately at the same temperature. When conducting pressure tests at low metal temperatures, the possibility of brittle fracture shall be considered." As you said, the piping material has been selected and charpy tested for suitability at the design temperature, the glycol is an acceptable testing medium, you know your local regulations of how to dispose of it after test, so what else do you need for the test. The posts above gave you some indications of how to proceed/organise your test, just in case you are still unsure what to do. If you are confident as you should be, go ahead, write the procedure, send it to your customer for approval and put a thick phone book in the back of your pants, in case of anything going wrong.
Cheers,
gr2vessels
No, there is no ASME Code preventing you to use of most suitable hydrotesting medium, except the service conditions and then only if you will be left with unwanted residues in your piping.
The testing requirements I believe are clear to you and are detailed in the B31.1, Clause 137.1.2 Temperature of Test Medium.
"The temperature of the test medium shall be that of the available source unless otherwise specified by the Owner. The test pressure shall not be applied until the system and
the pressurizing medium are approximately at the same temperature. When conducting pressure tests at low metal temperatures, the possibility of brittle fracture shall be considered." As you said, the piping material has been selected and charpy tested for suitability at the design temperature, the glycol is an acceptable testing medium, you know your local regulations of how to dispose of it after test, so what else do you need for the test. The posts above gave you some indications of how to proceed/organise your test, just in case you are still unsure what to do. If you are confident as you should be, go ahead, write the procedure, send it to your customer for approval and put a thick phone book in the back of your pants, in case of anything going wrong.
Cheers,
gr2vessels
Here is good paper on EG that maybe of some help. You notice they give freeze and burst protection temperatures.
If you plan to reuse the test fluid I would certainly think about using an inhibitor like the ones mentioned in the paper. If there are environmental concerns you might want to use Propylene Glycol.
If you plan to reuse the test fluid I would certainly think about using an inhibitor like the ones mentioned in the paper. If there are environmental concerns you might want to use Propylene Glycol.
- Thread starter
- #12
Gents, I've found also that during cold weather, the following options may be utilized to warm the metal temperature to acceptable levels instead of using antifreeze:
Steaming the line;
Running warm water through the pipe;
Energizing steam tracing on the line.
Do you think that it's feasable for pipes laying on a Pipe Rack?
I think that the easiest way, after having solved all environmental impacts with local authorities, is to use antifreeze. Who can tell me wich is less harmfull for ambient and that garantee an excellent result during hydrotest between Ethylene or Propylene Glycol?
Thanks again
Steaming the line;
Running warm water through the pipe;
Energizing steam tracing on the line.
Do you think that it's feasable for pipes laying on a Pipe Rack?
I think that the easiest way, after having solved all environmental impacts with local authorities, is to use antifreeze. Who can tell me wich is less harmfull for ambient and that garantee an excellent result during hydrotest between Ethylene or Propylene Glycol?
Thanks again
gr2vessels
Mechanical
The glycol solution will rapidly cool down any heat you might put in the piping material. Holding the pressure for one hour in the pipe will see temperatures below zero anyway. The cost seems to be of no matter to you, so if you can afford it, heat trace the pipe for the hydrotest. Make sure to trace the pipe in uniform covering to not induce additional thermal stresses due to uneven heating.
The propylene glycol seems to be a bit more friendly to the environment, but you can't just discharge it on the ground, so select the cheaper one and do the test in the afternoon at higher temperature. Collect the antifreeze and dispose of it as per the local authority recommendation. Keep some for your car. As far as guarantees concerns, you are not really expecting someone on this forum to sign a guarantee paper to your satisfaction, do you?
cheers,
gr2vessels
The propylene glycol seems to be a bit more friendly to the environment, but you can't just discharge it on the ground, so select the cheaper one and do the test in the afternoon at higher temperature. Collect the antifreeze and dispose of it as per the local authority recommendation. Keep some for your car. As far as guarantees concerns, you are not really expecting someone on this forum to sign a guarantee paper to your satisfaction, do you?
cheers,
gr2vessels
- Thread starter
- #14
- Thread starter
- #15
I've found that answer and I would like to know from you if it's applicable in my case or not:
ASME B31.8 allows static tests with air up to 70% of SMYS. I've tested lines longer than your 10,000 ft with air with excellent results. You didn't say the diameter of your line or the test pressure, but as long as you keep the hoop stress below 70% of SMYS and your area classifications are consistent with ASME B31.8 air tests you can save yourself a lot of pain and suffering by just doing the test with gas (either air or an inert gas). All of the calculations are in ASME B31.8 or you can look at my web page for a document that pulls the issues into one package.
There are people in these forum that will tell you that I'm giving you irresponsible advice, and that the total stored energy in an air test is just too great to be risked. ASME disagrees with that assertion, and I've done dozens of big static tests with air with great success by following all of the rules.
Regardless of your final choice of test media, be very careful of the temperature that you put into your calculations. Eastern Canada in April can be pretty chilly and cold temperatures shift the brittle-failure curve dramatically.
David Simpson, PE
MuleShoe Engineering
If yes, how do I recalculate/convert the pneumatic test pressure from the Hydrostatic one?
If I will have to use Ethylene Glycol as my only solution my question is:
As the bulk modulus of water/antifreeze mixture is different from that of water alone, the volumetric expansion coefficient will be different.
How do I calculate the pressure/temperature variation?
Thanks
ASME B31.8 allows static tests with air up to 70% of SMYS. I've tested lines longer than your 10,000 ft with air with excellent results. You didn't say the diameter of your line or the test pressure, but as long as you keep the hoop stress below 70% of SMYS and your area classifications are consistent with ASME B31.8 air tests you can save yourself a lot of pain and suffering by just doing the test with gas (either air or an inert gas). All of the calculations are in ASME B31.8 or you can look at my web page for a document that pulls the issues into one package.
There are people in these forum that will tell you that I'm giving you irresponsible advice, and that the total stored energy in an air test is just too great to be risked. ASME disagrees with that assertion, and I've done dozens of big static tests with air with great success by following all of the rules.
Regardless of your final choice of test media, be very careful of the temperature that you put into your calculations. Eastern Canada in April can be pretty chilly and cold temperatures shift the brittle-failure curve dramatically.
David Simpson, PE
MuleShoe Engineering
If yes, how do I recalculate/convert the pneumatic test pressure from the Hydrostatic one?
If I will have to use Ethylene Glycol as my only solution my question is:
As the bulk modulus of water/antifreeze mixture is different from that of water alone, the volumetric expansion coefficient will be different.
How do I calculate the pressure/temperature variation?
Thanks
I've done many tests with air, many with water. I have seen both fail. Water test, vessel failure...I got soaked. Air test, pipe failure.... well, let's say that the guy that lost the finger got it easy, the massive hole in the wall was a different story.
ASME will allow you for air test, but if you have the option with liquid, what is the point of risking it?
Run with scissors; just keep the pointy end in your fist.
<<A good friend will bail you out of jail, but a true friend
will be sitting beside you saying ” Damn that was fun!” - Unknown>>
ASME will allow you for air test, but if you have the option with liquid, what is the point of risking it?
Run with scissors; just keep the pointy end in your fist.
<<A good friend will bail you out of jail, but a true friend
will be sitting beside you saying ” Damn that was fun!” - Unknown>>
we used to test large silos and blenders at 1/4 psi air because shell would not hold weight of water for test.
even with that low pressure...the shop was evacuated as pressure came up.
air is extremely dangerous. Don't believe it?
Go out and knock the valve off of an argon or nitrogen compressed gas cylinder.
I did enough dodgin of shrapnel 40 years ago....don't need additional practice
even with that low pressure...the shop was evacuated as pressure came up.
air is extremely dangerous. Don't believe it?
Go out and knock the valve off of an argon or nitrogen compressed gas cylinder.
I did enough dodgin of shrapnel 40 years ago....don't need additional practice
aironyx,
In your post dated 9 Oct 08 23:37, you quoted a long-time member of eng-tips, zdas04. The proper format for quoting is to use the TGML quoting function. Also, that quote was obviously in the context of a different question, so it would be appropriate to provide a link to that discussion.
Honestly, I think that is zdas04 had intended an answer similar to what they provided in this previous post, they would have responded with either a link themselves, or essentially repeated the answer. Unfortunately, your post makes it seem as if they agree with you, which may not be the case.
Please provide the clarifications that I have asked for, and hopefully zdas04 will respond as to whether or not their opinion on your issue is the same as what you quoted, or not.
Please note that I think that it would be appropriate for you to "Red-Flag" your post, and ask the forum moderator to fix the post for you, with the proper quotations and link to the referenced thread.
In your post dated 9 Oct 08 23:37, you quoted a long-time member of eng-tips, zdas04. The proper format for quoting is to use the TGML quoting function. Also, that quote was obviously in the context of a different question, so it would be appropriate to provide a link to that discussion.
Honestly, I think that is zdas04 had intended an answer similar to what they provided in this previous post, they would have responded with either a link themselves, or essentially repeated the answer. Unfortunately, your post makes it seem as if they agree with you, which may not be the case.
Please provide the clarifications that I have asked for, and hopefully zdas04 will respond as to whether or not their opinion on your issue is the same as what you quoted, or not.
Please note that I think that it would be appropriate for you to "Red-Flag" your post, and ask the forum moderator to fix the post for you, with the proper quotations and link to the referenced thread.
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