Changes in temperature are known to have varying kinds of impacts on machines and when a container or device is meant to hold items at very high pressure and/or very low temperatures, your standard containers and equipment do not suffice. You will need tanks etc that are specifically fabricated to handle the below freezing temperature. In most industries these are known as cryogenic equipment and it is purpose made depending upon material to be stored or processed as well as industries where such equipment will be used.
What is Cryogenic Equipment Fabrication?
Temperatures below -238 degrees Fahrenheit (-150 degrees Celsius for those out of North America) are called cryogenic temperatures and these are so low that a regular industrial equipment or storage tank will simply fail if anyone tries to store any material at such low temperatures in them. Currently the most common use of such systems is being done for storage and movement of Liquified Natural Gas though other applications in sectors such as aviation, medicine and various other scientific fields is also very widespread.
Production of tanks and equipment for these kinds of purposes is specially defined and controlled as per a broad set of guidelines. For example, ASME Code Section VIII deals with the certification of firms which are involved in production of cryogenic vessels. Some other equipment that is being produced for such extreme temperature applications includes Vacuum-insulated containment vessels, Heat Exchangers and Cold Boxes, Process Control and Distribution systems, Purifiers, Adsorbers, Evaporators, Liquefiers, Refrigeration Systems, Vacuum Jacketed Piping Systems, Dewars and Cryostats etc.
The manufacturing of items which can withstand such low temperatures requires specialized knowledge of materials and welding techniques Common materials used in low temperature applications include stainless steels, aluminum, nickel alloys, and specialized low-temperature alloys. The vessels also have to undergo various tests like hydrostatic testing, vacuum testing, pressure testing etc.
Different Kinds of Tests for Low Temperature Contains and Equipment
A reliable manufacturer will always test their product before shipping it to the customer. Considering the very nature of cold temperature equipment, a number of tests are done by manufacturers before they can certify any item they have manufactured as ready for sale.
- Hydrostatic testing is a method for assessing the integrity and safety of cryogenic equipment, including vessels and pipelines. The hydrostatic test involves pressurizing the equipment with a liquid, typically water, to a specified level to ensure that it can withstand the designed operating pressures without leaking or failing.
- Leakage and pressure testing are methods which allow a manufacturer to check for leakage in the item as well as to ensure the structural rigidity and overall usability of anything they have manufactured for cryogenic usage. Manufacturers will try to create a vacuum inside the tank and if making a vacuum is not possible, it clearly shows that there is some kind of leakage which is allowing air in. Other leakage test involve dipping a closed container in water to check for escaping air bubbles.
- External or Internal pressure tests are also done where if a container deforms or changes shape, or in worst case scenario, outright implodes, this shows that material of which the container or pipe is made is not very durable and is at risk of collapse which can lead to a lot of problems.
- Vacuum tests are done on such low temperature devices to ensure that they can operate under a specific vacuum environment. The objective is that the storage tank or piping should not spring leaks and can maintain the required vacuum levels.
If you are looking for cryogenic vessel fabrication services, make sure you choose a local company with a very reliable track record that can corroborate their claims with appropriate industry certifications.
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