The best testing methods for an industrial system component mimic its service conditions. That way, testing can confirm function, stability, and durability against service-induced stresses.
That is why components/systems that operate at low temperatures or involve gaseous/liquid cryogen need extreme low-temperature cryogenic testing services.
What Is Cryogenic Testing For?
Low-temperature and cryogenic systems need cryogenic testing services for two purposes. As a type of fugitive emissions testing and also for extreme cold shock testing [1]*.
Yet as recently as 50 years ago, few firms had use or need for cryogenic testing services. Relatively few systems operated at or near cryogenic temperatures (as low as 4° Kelvin/-268 °C/-450 °F). By contrast, today, low-temperature and cryogenic systems play key roles in many industries. These include the oil, gas, petrochemical, power generation, electronics, and aerospace sectors [2]. What's more, these systems are often involved in the control of hazardous materials.
The Benefits Of High-Quality Cryogenic Testing Services
Developing and maintaining systems used in these (and other) applications has created a need for more extreme testing. Cold shock testing and leakage/emissions-focused cryogenic testing of valves and other components are now common evaluations. They appear in both quality control and failure analysis efforts across a broad range of industry sectors.
Less-extreme types of testing identify the load level that would result in failure. Cryogenic testing services — including both cold shock testing and cryogenic leak detection — do more. They can also identify microscopic damage that occurs before failure [3]. These tests go beyond ensuring system safety and functionality under anticipated operational conditions. They can confirm the efficiency, performance quality, and standards compliance of the system.
Subjecting systems and components to mechanical function and fugitive emissions testing at cryogenic temperatures is therefore essential.
Cryogenic Testing Services In Context
Still, it is still one of the more extreme inspection methods available. In the contemporary applications above, applying appropriate cryogenic testing procedures is essential for:
- Valves and interfaces (especially control valves, isolation valves, and pipeline interfaces);
- Components constructed of advanced composite materials;
- Cryogenic pressure vessels.
In these cases, cryogenic testing of valves and other components can guarantee performance. This is especially important in consideration of national- and industry-specific standards.
What Do Stakeholders Gain From High-Quality Cryogenic Testing Services?
Cryogenic testing of valves and other components for mechanical function and emissions impacts:
- Most industrial valve manufacturers and end-users;
- Manufacturers/designers/operators of systems designed for cryogenic purposes;
- Manufacturers/designers/operators of systems involved in special service applications. This includes high-pressure pipelines, hazardous fluid/gas systems, and nuclear power components [4].
For each of these stakeholders, assurance is essential. It impacts operational safety, product quality, system costs, and competitive reputation.
What Is The Cryogenic Testing Procedure Of Valves And Other System Components?
Cryogenic testing procedures generally involve liquid nitrogen immersion, fill/flow, or spraying. Depending on system and customer requirements, technicians can combine these procedures. Doing so improves the data available about the component’s performance at cryogenic temperatures.
Specific Cryogenic Testing Procedures:
These cryogenic testing procedures can be hazardous and should only be performed by a qualified technician. Your technician may:
- Construct or provide an appropriate vessel to contain and immerse components for evaluation;
- Submerge the component in liquid nitrogen or, less often, liquid natural gas;
- Fill (or flush) the component in question with liquid nitrogen;
- Spray the component with a locally concentrated stream of liquid nitrogen;
- Look for evidence of mechanical failure or cryogenic leakage at cryogenic temperatures. This may involve evaluating mechanical fracture toughness as well as fatigue, tensile, and/or impact testing.
Interpreting Cryogenic And Cold Shock Testing Results
These analyses stress-test components at (or below) operating temperatures. A single system or component may need both cryogenic leak/fugitive emissions testing and cold shock testing. That said, components used at a consistent low temperature may not need much thermal shock resistance**.
Factors Impacting Cryogenic Testing Procedures For Valves & Other Components
Cryogenic testing services can serve different purposes and support different organizational goals. This focus of specific cryogenic test procedures varies depending on certain factors. These include:
- Individual system design characteristics;
- Project location and associated regional requirements for cryogenic testing procedures;
- Expected operating conditions; and
- Other unique client specifications.
This flexibility is both a strength and potential weakness of even all cryogenic testing procedures. Differing (and frequently changing) regional/national and industry-specific standards cause this weakness. Inconsistency — especially for acceptable leakage rates and load forbearance — challenge test result reliability.
How Cryogenic Testing Service Providers Impact Test Results
The impartial, third-party analysis of test results is a key benefit of cryogenic testing services. Even so, knowledgeable and experienced service providers can influence test result reliability. They can design cryogenic testing procedures for valves and other components to yield the most useful data possible.
Consider that the cryogenic testing of valves is beholden to few consistent standards. As a result, individual manufacturers and system operators often set their own standards. This is true for cryogenic testing procedures/levels for both internal and external leakage rates [5].
That is why it is critical to work with a qualified, professional cryogenic testing service provider. As you might expect, they can create customized cryogenic testing procedures for each component or system. Yet they can also provide important guidance about appropriate testing standards. That ensures the greatest-possible relevance and usability of test results.
What All PFC Cryogenic Testing Services Have In Common
Cryogenic testing procedures are make-or-break investments for many firms.
That is why all PFC cryogenic testing services are designed and carried out by qualified, experienced technicians. It is also why PFC invests in the training and equipment needed for leading-edge cryogenic testing procedures. Contact us today to find out more about what that means for you and the cryogenic testing procedures we have available to fit your needs.
*It is important to note that there is some significant difference between the various types of low-temperature function/durability testing available. Contact a qualified test administrator for guidance concerning the appropriateness and applicability of specific test-types, including thermal shock endurance testing, thermal cycling testing, hot-to-cold thermal shock testing, and more.
**Thermal shock resistance — quantified as the greatest change in temperature a brittle material or component can sustain without damage — is especially important in systems where normal operating conditions create a thermal/temperature cycle wherein components are subject to rapid heating and cooling processes.
Sources:
- https://www.swri.org/industry/flow-component-testing/valve-integrity-fugitive-emission-cryogenic-testing
- https://www.airliquide.com/industry/industrial-cryogenics
- https://www.researchgate.net/publication/268476142_Prediction_of_Leakage_Rate_Through_Damage_Network_in_Cryogenic_Composite_Laminates
- https://www.valvemagazine.com/magazine/sections/features/4411-extreme-valve-testing.html?showall=1&start=0\
- https://www.valve-world.net/webarticles/david-sear/cryogenic-valve-testing-what-are-the-shortcomings.html