Help: Cryogenic Test Failure Analysis - Valve engineering

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Help: Cryogenic Test Failure Analysis

Help: Cryogenic Test Failure Analysis

JLee81

(Mechanical)

(OP)

15 Oct 08 10:05

A couple of weeks ago, we tested a cryogenic triple offset valve and turn out that the helium nitrogen gas start leaking above tolerance level at -120C and the the amount of leak got worse as the temperature got close to -256C. Then when the temp. came back around -120C the leak was in the tolerance level again. Aslo the valve worked fine in ambient temp. and above. What do you think is the possible cause of the leak after a certain cold temp? Need your professional inputs. Thanks.  

RE: Help: Cryogenic Test Failure Analysis

terje61

(Mechanical)

15 Oct 08 11:41

Hello JLee81,

This sounds like your seals or other closure members are shrinking at different rates. When the temperature is going down the gab between the two parts becomes larger.

Regards,
Terje

RE: Help: Cryogenic Test Failure Analysis

terje61

(Mechanical)

15 Oct 08 11:45

Forgot to mention that if you want to solve this you can:
- Use different sealing materials that are less susceptible to shrinkage.
- Change the design so that the parts that are more susceptible to shrinking are on the outside of the parts that shrink less. This way your valve will be more tight during lower temperatures.
 

RE: Help: Cryogenic Test Failure Analysis

gerhardl

(Mechanical)

17 Oct 08 06:28
Are you the producer? If not: In addition to terjes good and sensible answer: are you sure the valve is a 'real' cryogenic valve, consructed for this temperature, medium and demanded leakage rates?

Sealing construction and sealing mounting and fastening construction and materials?

Are you the producer? If not: In addition to terjes good and sensible answer: are you sure the valve is a 'real' cryogenic valve, consructed for this temperature, medium and demanded leakage rates?Sealing construction and sealing mounting and fastening construction and materials?

RE: Help: Cryogenic Test Failure Analysis

JimCasey

(Mechanical)

20 Oct 08 09:30

Is this a seat leak or a packing leak?  
Either way, as tergew says, you have parts that do not fit as well when they shrink with the cold.

If it is a seat leak, you might be able to supply more closure torque with the actuator.  Or check with the manufacturer for a different seating material/arrangement.

If it's a packing leak, graphite packing tolerates thermal extremes better than polymeric (TFE) packings.  Live-loading the packing helps with thermal compensation also.

If you specified x leakrate at -(y) degrees, the manufacturer is pretty much responsible to re-do the valve until it meets your needs, unless he took exception to your spec or proposed something different.    

RE: Help: Cryogenic Test Failure Analysis

NGiLuzzu

(Mechanical)

20 Oct 08 10:54
      did you use a the helium + nitrogen gas mixture?
      What if you try with

helium

gas

only

?

      I've seen a lot of cryogenic tests, but all with the valve immersed in liquid nitrogen at

-196°C

... how did you reach

-256°C

? And, most of all...

why?

       

      I agree with the suggestions above: if the seats starts leaking at low temperature, probably it is not a real "metal to metal" sealing designed for such low temperatures...

Hope this helps,    'NGL    

    

JLee81,did you use a the helium + nitrogen gas mixture?What if you try withgasI've seen a lot of cryogenic tests, but all with the valve immersed in liquid nitrogen at... how did you reach? And, most of all...I agree with the suggestions above: if the seats starts leaking at low temperature, probably it is not a real "metal to metal" sealing designed for such low temperatures...Hope this helps,

RE: Help: Cryogenic Test Failure Analysis

belowzero

(Mechanical)

21 Oct 08 15:59

Hi Jlee81
 As NGL has identified the jump from -120 to -256C is rather a big one, as Nitrogen is a liquid at -196C I assume 100% Helium was used.
 What was the cryogenic valve manufacturers test/design temp? Having cryogenicaaly tested more Triple offset valves then I care to name, it would help if there was an 'indication' as to the manufacturer, it would be easier to help you then. There are a lot of questions which would need to be asked before this can be solved, however why are you using a forum and not referring back to the manufacturer.
 I don't know any valves above about 1/2" which are capable of -256C. The cost alone to test at these temparatures is astronomical.
B

RE: Help: Cryogenic Test Failure Analysis

Gobio

(Industrial)

25 Mar 09 16:32

I´m really interested in tests of cryogenic valves. Could you please give me references about this subject. Any document would be helpful for me.
Thanks

RE: Help: Cryogenic Test Failure Analysis

NGiLuzzu

(Mechanical)

26 Mar 09 03:56
       almost all the Customer Specifications about

cryogenic testing of industrial valves

assume the form of an amendment and/or supplement to

BS 6364

standard, an old one... but in many case

the only one

applicable, as of today...

       You can find one exception to this approach in the last editions of

Shell

specification (MESC SPE 77/200 incorporating and superseding the "old" MESC SPE 77/306) that arises as a "stand-alone" document.    
       
       Moreover an

EN 12567

standard for LNG valves exists (but it is still rarely applied and unfamiliar to many Engineering Companies), while

ISO

/TC 153 Committee is working on a draft about isolating valves for low temperatures (ISO/WD 28921).     

       For more information, you may want to take a look at the following discussions within this Forum:

           -    thread408-148535: Alternative to BS 6364 for cryo-testing?;

           -    thread408-207994: EN 12567 (2000) Type tests for on-off LNG valves;

           -    thread182-151721: ISO/DIS 21011 & TC 153 for Valves Cryo-Testing.

       May be then you will find worth to start a new, dedicated Thread about this issue...





JLee81,
       coming back to the original post, how about

torques

?

       Tripple-offset valves are typically

torque-seated

, but you don't mention anything about this aspect (as well as about pressures and test directions...)...?





Best Regards to All,        'NGL
 

Gobio,almost all the Customer Specifications aboutassume the form of an amendment and/or supplement tostandard, an old one... but in many caseapplicable, as of today...You can find one exception to this approach in the last editions ofspecification (incorporating and superseding the "old") that arises as a "stand-alone" document.Moreover anstandard for LNG valves exists (but it is still rarely applied and unfamiliar to many Engineering Companies), whileCommittee is working on a draft about isolating valves for low temperatures ().For more information, you may want to take a look at the following discussions within this Forum:May be then you will find worth to start a new, dedicated Thread about this issue...JLee81,coming back to the original post, how aboutTripple-offset valves are typically, but you don't mention anything about this aspect (as well as about pressures and test directions...)...?Best Regards to All,

RE: Help: Cryogenic Test Failure Analysis

Gobio

(Industrial)

26 Mar 09 08:02

Has someone the Shell specification MESC SPE 77/200, ISO/DIS21011 and TC153 for my information?

Thanks, Gobio

RE: Help: Cryogenic Test Failure Analysis

NGiLuzzu

(Mechanical)

26 Mar 09 08:53
         for

Shell

specifications you should refer to

Shell Global Solutions International

:
http://www.shell.com/home/content/global_solutions/
         

         

ISO

drafts instead are not for pubblic circulation until they are released as official standards, but are distributed for review and comment to the Committee Members only... so you may try to ask your national standards Institution (BS, DIN, AFNOR, UNI, JIS, GOST-R, CAS, ASRO, CSA, etc.) which should be

ISO

Further reading:
5 Budget-Friendly Non Slam Check Valve Deals You Need
What shut-off valve should be open and which closed?
Valves & Valve Repair

Xiangyu contains other products and information you need, so please check it out.

Member.


Hope this helps,                'NGL

Gobio,forspecifications you should refer todrafts instead are not for pubblic circulation until they are released as official standards, but are distributed for review and comment to the Committee Members only... so you may try to ask your national standards Institutionwhich should beMember.Hope this helps,

RE: Help: Cryogenic Test Failure Analysis

Gobio

(Industrial)

27 Mar 09 03:38

Thanks anegri,

I have a new question: Are the material requirements indicated in ASME (ASME II and ASME VIII for Charpys..etc) enough in order to design a valve for cryogenic service?

Thanks

 

RE: Help: Cryogenic Test Failure Analysis

Gobio

(Industrial)

1 Apr 09 12:51

Where can I purchase a test bench for testing cryogenic valves?

Thanks

RE: Help: Cryogenic Test Failure Analysis

NGiLuzzu

(Mechanical)

2 Apr 09 03:26
      as far as I know, cryogenic testing is usually performed applying flanged test

caps

to the valve and submerging the resulting assembly into liquid nitrogen within an insulated

tank

, and all is confined in a protected, dedicated

area

(sometimes a hole in the ground...); the above mentioned standards and specifications generally provide for a scheme of the test rig.

      I believe that cryogenic testing on a bench may be feasible for very small valves only, nowadays... but I would appreciate other Members' opinion on this aspect.
      I also investigated such a possibility, some years ago, withih this Forum: please take a look at
  

Hope this helps,        'NGL

______________________________
 

Gobio,as far as I know, cryogenic testing is usually performed applying flanged testto the valve and submerging the resulting assembly into liquid nitrogen within an insulated, and all is confined in a protected, dedicated(sometimes a hole in the ground...); the above mentioned standards and specifications generally provide for a scheme of the test rig.I believe that cryogenic testing on a bench may be feasible for very small valves only, nowadays... but I would appreciate other Members' opinion on this aspect.I also investigated such a possibility, some years ago, withih this Forum: please take a look at thread774-127182: Cryogenic Test Bench for Valves Hope this helps,______________________________

RE: Help: Cryogenic Test Failure Analysis

Gobio

(Industrial)

4 Apr 09 00:39

Anegri,

I also heard about the possibility of testing cryogenic valves pulverizing them with liquid Ni instead of submerging them into it. What do you feel about this?

RE: Help: Cryogenic Test Failure Analysis

NGiLuzzu

(Mechanical)

6 Apr 09 03:15

Gobio,
      if you mean spraying cold nitrogen around the valve, this is usually done in order to test at "low" temperatures (typically

-50°C

) instead of "cryogenic" ones (

-196°C

).
      Of course, in that case, keeping temperatures steady is more difficult than in case of immersion in liquid.

Hope this helps,        'NGL     

 

RE: Help: Cryogenic Test Failure Analysis

Gobio

(Industrial)

9 Apr 09 00:30

Anegri,

All your information helps me a lot. Thanks.

Then the only way of testig valves at cryogenic temperatures it´s submerging them into the liquid Ni within an insulated tank.

What do you know about safety requirements for the tests in these tanks?

What size are you thinking about when you say "very small valves only"? How can we test big valves?

Gobio.
 

RE: Help: Cryogenic Test Failure Analysis

Gobio

(Industrial)

23 Apr 09 02:10

Dear Anegri,

- Do you know about any reference or standard where the test at "low" temperatures (-50ºC) by sprayind is explained?

- What do you think about the safety requirements for both tests "low temperatures by spraying" and "cryogenic temperatures by immersion".

Best regards
 

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News

As mentioned earlier, cryogenic equipment is used in a wide range of industries. Over the past decades, Demaco has delivered infrastructures in ten different sectors, and all these industries have their own focus and specific requirements:

1. Automotive

In the automotive industry, cold shrink technology is prevalent. This advanced technology ensures that individual engine components temporarily reach a freezing temperature and shrink slightly, allowing them during assembly to be pressed into the engine with a light force. As the part warms up again, it expands and will be firmly anchored in the engine.
Liquid gases are used to bring parts rapidly to extreme cold, and cryogenic infrastructures are needed to do this.

2. Electronics

A second industry in which cryogenic technology has a significant role is the electronics industry. It is mainly during the testing of electronic devices that extremely cold liquid gases are applied. Liquid nitrogen is commonly used to test whether the equipment can withstand cold temperatures in everyday use.

3. Food

In the food industry, liquid gases are used for cryogenic cooling and the safe packaging of products. Some of the advantages of cryogenic technology in this industry are the processing speed and the fact that products are preserved for a long time while optimally retaining their shape.

4. LNG

The LNG industry is growing at a rapid pace. LNG (Liquefied Natural Gas) offers some environmental advantages for the shipping and road transport sector and is, for that reason, increasingly used as a fuel. To keep LNG liquid, it must be stored at -162 ℃, which requires advanced cryogenic infrastructures.

5. Marine

LNG is used and stored in the marine industry in several ways. Some ships use the gas as fuel, while others transport it in large storage tanks (bunkers). Storage facilities for LNG can also be found in port areas: which are dubbed LNG-plants.

6. Medical

Liquid nitrogen is especially popular in the medical field. This liquid gas is used to perform specific medical treatments and to preserve complex biological structures (this method, called cryopreservation) is used to preserve blood, cells, organs, DNA, and semen).

7. Pharmaceutical

Liquid nitrogen also plays an essential role in the pharmaceutical industry. This liquid gas is widely used to cool cryogenic storage vessels and for molding medicines into pill form.

8. Scientific research

Cryogenic gases, besides being ultra-cold, can also generate tremendous power. For this reason, these gases are often the subject of physics studies. Helium is one of the coldest and most potent liquid gases; therefore, it is widely used to cool particle accelerators.

9. Space

Partly because of the enormous power that cryogenic gases can generate, they are regularly used within the space industry. For example, cryogenic techniques are used to launch satellites and vehicles; liquid gas is fuel (for a cryo engine). At the same time, cryogenics are frequently part of scientific experiments in the space industry.

10. Hydrogen

Interest in hydrogen is growing significantly. Hydrogen is a versatile, clean, and safe energy carrier that can be used as a “fuel” in a fuel cell or as a feedstock in the industrial sector. When hydrogen is combusted, only (water) vapor is released. This makes hydrogen a unique fuel in terms of sustainability. Hydrogen will play an increasingly prominent role in the marine industry, the industrial sector, and the space industry in the coming years.

11. Air separation

A last, but certainly not least, market is the air separation industry. Air separation takes place in air separation units; in short, this means the purification of air for the bulk production of nitrogen, oxygen, argon, and some noble gases.

 

For more information, please visit Industrial Cryogenic Valve Manufacturers.