Given their high tolerances for extreme temperatures, it is no wonder that metal hoses are a preferred choice when it comes to high-temperature applications. With that said, are metal hoses also suitable for low-temperature use cases? The quick answer to this common question is yes; they remain an excellent choice for low temperatures. Having said that, there are some key factors to consider before opting for metal hoses.
It is imperative to first make sure of the operating conditions in which the hose will be used, starting with the maximum and minimum temperatures of the given application. If the given assembly is subject to large temperature variances, it is critical to determine how quickly and frequently the temperature changes will be. As a reminder, metal expands and contracts at different rates as they heat up and cool down based on the alloy. Thus, severe temperature fluctuations will apply considerable stress on the welded joints and possibly lead to cracks developing.
One method of checking if an assembly can handle such stresses without issue is by performing a cold or thermal shock test, wherein an assembly is submerged in a cryogenic bath and exposed to the highest temperature it will experience. Afterwards, inspection and various testing methods are conducted to ensure the welds will not suffer from cracks under the same extremes during live operation.
Another condition that operators should check is the presence of temperature extremes inside and outside the hose, i.e., media temperature and the external environment. Will the hose be transferring cryogenic fluids? Will it be buried under the ice? Is it possible for the media to freeze inside? These are only a few of the many possible conditions that can be avoided by choosing the right assembly for the task.
Standards and certifications
Besides service conditions, operators must determine the standard requirements of the application, which may be challenging given the various standards that apply depending on its forming process, alloy, and final product. Verifying the applicable standard is essential due to the difference in low-temperature ratings various standards may have for the same alloy. Furthermore, keep in mind that certain alloys can have multiple certifications, which means they comply with more than one standard, each with different ratings for a certain alloy. In these cases, the standard that the customer specifies will dictate the minimum temperature rating.
Lastly, the fabrication method could also affect the acceptable low-temperature limits. Many standards reference or include differing welding requirements that welders are required to achieve and maintain compliance with. These standards generally dictate the acceptable low-temperature limits of a welder’s certification and supersede the limits of the materials.
In short, when it comes to the operating temperatures of metal hoses, there is no quick answer to how low they can go. Determining as many details as possible of the given application, along with the applicable standards, is essential to ensure the assembly materials conform to the required specifications.
At Pharmchem Engineering, we provide the best metal hoses in Singapore, perfect for various applications and extreme environments. With decades of quality experience in the industry, we are the one-stop shop for all your industrial engineering supplies, including anti-vibration mounts, pipe-pigging equipment, dry disconnect coupling, and metal, rubber, and fabric expansion joints. To learn more details about our products and custom solutions that deliver to your needs, don’t hesitate to contact us at any time.