Cryogenic Testing & Cold Shock Testing

Cryogenic Testing & Cold Shock Testing

Cryogenic Testing & Cold Shock Testing

Ensuring Continued Industrial Valve Viability & Functionality Under Extreme Conditions

 

The Role Of High Valve Failure Rates & Low Temperature Tests In Industrial Loss Prevention

Many of the most effective methods of industrial loss prevention involve taking steps to prevent mechanical failure in pressurized systems, especially where flammable or explosive materials are present. Valves, pneumatic actuators, and mechanical pressure sensors are among the most reliable parts of any pressurized system or pipeline. Yet exposure to extreme conditions outside their designated operating conditions — including unanticipated low temperatures and high pressures — is the second-most-common cause of failure in these critical system components [1].

In some industrial settings, mechanical fatigue is responsible for up to one-third of valve and related component failures; the underlying cause of this fatigue is most often installing valves that are unsuitable for the given operating conditions [2]. Moreover, valve failure rates in industrial settings where the stored material is flammable are particularly sensitive to whether the vessel has a weak roof seam, which is equal-parts necessary for preventing catastrophic failure in overpressured systems and dangerous design decisions [3]. In any industrial setting, the highest valve failure rates are attributed to low temperature exposure, making cold failure the most common cause of catastrophic releases [3]. Consequently, cold shock testing — like the cryogenic testing performed by Precision Fabricating & Cleaning — is an essential industrial loss prevention tool when designing any high pressure system or pipeline.

 

What Is Cryogenic Testing?

Cryogenic testing in industrial applications — sometimes called cold shock testing or low temperature testing — is a highly specialized process through which valve, actuator, and sensor equipment are verified as being safe for use under extreme conditions.

In practice, cryogenic testing involves submerging mechanical components in liquid nitrogen at temperatures between -50°F (-46°C) and -320°F (-196°C). Components are then tested for leaks and changes in flow rate (by flooding the system with test gases) that may signal compromised viability and functionality [4]. This process is available for almost every valve type and involved actuator or sensor component.

 

What Are The Most Common Industrial Applications Of Cryogenic Or Cold Shock Testing?

Extreme low temperature tests are most desirable for systems that handle hazardous fluids, as well as those in nuclear power plants and high-pressure (oil and natural gas) pipelines [4]. Among these industries, cryogenic testing is most popular for use with liquid natural gas system components, as the best low temperature testing firms/facilities can create well-calibrated cryogenic testing procedures at exactly 60° F (-162° C) — the temperature of liquid natural gas [4].

Because the businesses buying these types of equipment components are increasingly more likely to use them under extreme conditions that fall outside the advertised safe/viable operating range, valve system manufacturers have begun adopting cold shock testing as a standard practice when bidding on contracts for special services applications [4]. As a result, the best cold shock testing firms should operate facilities capable of performing low temperature tests on differently sized batches of components for different purposes. When working with individual firms, cryogenic testing firms should be appropriately equipped to verify the durability and low temperature resistance of a specific system. When working in service of a mechanical components manufacturer, that same firm should be prepared to establish a functional valve failure rate under low temperature conditions, which will then be reported to industrial consumers as a part of standard marketing practices.

 

How Does Well-Designed Cold Shock Or Cryogenic Testing Prevent Incidents?

It is important to note that the promise of cryogenic testing is not complete indemnification of any given valve, valve-related component, or in-application valve system. Rather, this form of industrial loss prevention helps firms identify the best and safest practices for manufacturing valve components, as well as processes for designing refinement, energy transportation, and other high-risk, high-pressure systems and pipelines.

The effect of this action is two-fold:

  1. Primarily, systems that make use of components backed by reliable low temperature test results under extreme conditions experience lower valve failure rates;
  2. Secondly, firms participating in such testing (or that seek out products and system components that have been so tested) engage in a kind of failure analysis that is particularly helpful in industrial loss prevention practices [5].

Additionally, firms that make the best possible use of customizable cryogenic testing processes can work to adequately manage the risk of operations so that any inevitable valve failures are just that: inevitable. The difference between an inevitable and an easy-to-prevent mechanical failure is significant. Choosing to prevent mechanical failure in this way can minimize both the frequency of failure and the property and personal damage — as well as the indirect costs of lost operational time and potential damage to a firm’s credibility — caused by an inevitable failure [6].

 

Cold Shock Testing Prevents Mechanical Failure In The Field & Reduces Valve Failure Rate

Some frequency of valve and valve-related component failure is always expected under standard risk management processes; statistically speaking, a certain number of valve systems under pressure will fail in some way during the course of their expected useful life. The average and acceptable valve failure rate varies depending on the type of valve in question, with pressure relief valves demonstrating by far the highest valve failure rate in the field (as much as  1%-1.6% within 4-5 years) [7].

The most common forms of pressure relief valve failure include failure to open on demand (or opening at a higher-than-anticipated pressure), opening in the absence of demand, leaking, and full valve disablement [8]. In each case, failure of the pressure relief valve contributes to increasingly dangerous situations for employees and bystanders alike. This is because the contents under pressure in the systems most often to require cryogenic testing — hazardous and flammable fluids, oil and natural gas, materials involved in nuclear energy creation — tend to be highly volatile and failure tends to be violent.

Consequently, cryogenic testing is especially important given that some kind of valve failure accounts for approximately half of the most common field failure modes of pressurized systems and pipelines [9]. When working to prevent mechanical failure of these systems in the field, an ounce of prevention is truly worth a pound of cure.

 

Do Digital Valve Technology & Control Systems Software Undermine The Importance of Cryogenic Testing In Industrial Applications?

Though contemporary digital valves and related softwares can help firms identify and respond to valve failure events near-immediately, they cannot prevent mechanical failure of a valve or any valve-related components [1]. Moreover, cryogenic testing prior to system assembly or initiation can increase the number of opportunities to identify how the use of different (mixed) seal materials increases the vulnerability of any given valve system to catastrophic failure under extreme conditions.

Consequently, despite recent innovation in valve and related component digitization, cold shock testing remains an integral part of any mechanical component manufacturer’s valve design process and valve marketing materials. Likewise, sourcing low temperature tested materials should remain a clear priority for firms designing valve systems for special services applications as described previously; doing so is an integral part of the best risk management procedures and is required under a variety of different international regulations.

 

How Do You Ensure The Cryogenic Testing Services You Receive Are Safe & Accurate?

Though it is immensely helpful to both manufacturing and special services/energy firms, cryogenic testing is highly dangerous and should only be performed by well-qualified professionals under tightly controlled conditions [4]. Consequently, companies interested in seeking standard or fully customized cryogenic or cold shock testing for valves and related components should consider working with a highly qualified and certified low temperature test administrator. Precision Fabrication & Cleaning is one such administrator; we have over 25 years of experience conducting safe, reliable, and accurate cryogenic testing for valves and components intended for use in a wide variety of industrial applications. Contact PFC today to find out more about our cryogenic testing services or request a quote.

 

Sources:

  1. https://www.flowcontrolnetwork.com/valves-actuators/article/15555201/qa-why-do-valves-fail
  2. https://www.hse.gov.uk/research/rrpdf/rr162.pdf
  3. https://www.hse.gov.uk/landuseplanning/failure-rates.pdf
  4. http://valvemagazine.com/magazine/sections/features/4411-extreme-valve-testing.html?showall=1&start=0
  5. https://dl.asminternational.org/handbooks/book/49/chapter-abstract/601033/Engineering-Aspects-of-Failure-and-Failure?redirectedFrom=fulltext
  6. http://etraintoday.com/blog/near-miss-vs-an-accident/
  7. https://www.exida.com/Resources/Whitepapers/results-of-statistical-analysis-of-pressure-relief-valve-proof-test-data
  8. https://books.google.com/books?id=73M6aqqy-uUC&pg=PA551&lpg=PA551&dq=mechanical+valve+failure+responsible+for+catastrophic+loss+high+pressure+system&source=bl&ots=_DiZ1-KwiO&sig=ACfU3U3UQuhfnswj_q6LPf-5q-mqx5TY4w&hl=en&ppis=_e&sa=X&ved=2ahUKEwi4hP_ZmMbnAhXCGTQIHSJsALEQ6AEwC3oECAkQAQ#v=onepage&q=%22valve%20failure%22&f=false
  9. https://sswm.info/sites/default/files/reference_attachments/WSAA%202003%20Common%20Failure%20Modes%20in%20Pressurised%20Pipeline%20Systems.pdf
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