Nonhazardous liquid for hydrostatic test during winter

[hcjulien]

Hi,

we need to do an hydrostatic test concerning a huge (internal volume more than 60,000 cu. ft.) pressure vessel manufactured outside during winter 2008-2009.

Can you give me ideas of none hazardous liquid you normally using in these cases (brainstorming)? The liquid shall be easily re-usable because our customer (petroleum refinery) is certified ISO 14001.

Note : the liquid flash point shall not be higher than 110F.

Thank in advance,

hcjulien

 

[nickelkid]

why the limitation on flash point?

 

[dcasto]

Should that be flash point will be higher than 110F?

How about bio diesel?

 

[nickelkid]

Propyleneglycol is friendly too.

 

[hcjulien]

Hi,

concerning the flash point request, ASME Section VIII div. 1 UG-99(h)is requesting a maximum flash point of 110F if combustible liquids is used near atmospheric temperature.

Many thanks dcasto and RCHandy for your answer.

Any others suggestions?

Regards,

Hcjulien

 

[unclesyd]

Your volume is rather large for liquids other than water so some disposal or storage facility is almost a must have.

What is the minimum temperature expected around your testing schedule?

 

[hcjulien]

Worst temperature expected during hydro test: -29C (-20F)

 

[eliebl]

As you mention a possible low temperature of -29C have you considered the chances of brittle fracture? At hydrotest the induced stress level at some point is higher than the allowable stress (assuming you are using the full MAWP).

I do not think that you will be able to find a non-freezing fluid similar to water that will not pose disposal problems.

EJL

 

[stanweld]

Water/glycol mixes have been used.

 

[JStephen]

It sounds like you'd be better off heating water rather than trying to find a water replacement.

Re-read that section you mentioned in UG 99. It's not requiring a low flash point. It says any fluid may be used, but if the flash point is below 110, it can only be used for near-ambient temperature tests.

 

[doct9960]

hcjulien,

Water added with antifreeze like methanol have been used during winter hydrotest. Check with the local environmental regulatory agency for requirements on hydrostatic testing.

What is the MDMT of the vessel? The Code "recommends" that the vessel metal temperature during hydrotest be maintained at least 30 deg F above the MDMT to minimize brittle fracture.

 

[zdas04]

It sounds like it would be cheeper to build a temporary building or tent around the vessel and keep the whole thing above freezing and use water. Brittle failure at low temperatures is both very common and very dangerous.

David

 

[athomas236]

I would go with the water option with a pumping and heating system to keep temperature within max and min limits, then just seal off and carry out hydro test in the normal way. The temperature drop from max over the time to do the test and inspections may not be so great to course concern but a few basic calcs should confirm this.

 

[hcjulien]

One of our process engineer suggest me the following option:

-jet fuel
-Artic diesel

Both are with flash point below 110F (important if combustible fluid is used, see UG-99(h))
Boiling point above 110F
Freezing point below -29C (-20F)
Reusable in the raffinery
Specific gravity below 1.0 (water)

 

[hcjulien]

Oups I forgot to ask you what do you think?

Please take note that the hydrostatic test temperature will be between 50F @ 110F (MDMT = -40F). Also the test pressure is 151 PSIG during 1 hour 10 minutes + time required for inspection.

Regards,

hcjulien

 

[doct9960]

Combustible liquid as test medium for a 60,000 cu. ft. vessel? Hmmm...potential fire, explosion and environmental damage if the vessel fails during test. Have you determined how many fire fighters and how many cubic feet of extinguishing foam you need on standby for the test? How about the containment system (e.g. dikes) in case of leak or spill?


In what country and state/province would this hydrostatic test take place?