Advanced EMC Technologies Blog
Posted in: Cryogenic Seals
Sealing in a cryogenic environment is hard enough, but when it involves fluids that are being stored or processed near their boiling point, it opens up a whole new set of challenges.
More and more industries are using cryogenically cooled liquids and gases, which is increasing the demand for transfer systems that can handle those kinds of temperatures.
Posted in: Cryogenic Seals
Cryogenic seals are required in a variety of industries, including LNG fueling systems, specialty gas manufacturing, cryo coolers, radio astronomy, scientific instrumentation, pharmaceutical research, and many more. One of the most reliable sealing solutions for cryogenic applications are polymer spring-energized seals. In this blog post, we are going to review spring-energized seals and then discuss what the recommended spring configuration is for cryogenic applications.
Cryogenic sealing applications are challenging, to say the least. One popular solution is the use of spring-energized seals, and in this blog post we are going to talk about the 3 post popular materials used for spring-energized seals for cryogenic applications: PTFE, modified PTFE, and UHMW PE.
One of the major challenges in working with LNG (liquefied natural gas) is transporting it. LNG is stored and transferred at cryogenic temperatures – which can be a major challenge when it comes to designing seals.
LNG applications can be challenging, with cryogenic temperatures and extreme temperatures combining to create a nightmare for your typical seal. However, there are excellent, reliable sealing solutions for LNG applications.
PTFE (polytetrafluoroethylene, tradename Teflon) is a polymer material commonly used in sealing applications that offers unparalleled stability and sealing characteristics across an extremely wide range of temperatures, as shown in the table below.
Cryogenic seals must not only handle unbelievable low temperatures, but also perform under high pressure conditions. If you aren’t familiar with cryogenic seals, a cryogenic seal is a special type polymer seal used with media at temperatures below -238°F and down to -460°F (absolute zero). Cryogenic seals can be found in a variety of industries, from LNG compressors and loading arms in the petroleum industry to rocket propulsion systems in the aerospace industry.
Other important articles on Cryogenic Seals from Advanced EMC Technologies:
Mechanical Loading Arms
Loading arms are flexible piping systems used to transfer chemicals to railcars, trucks, tankers,
ships, and barges. If the loading arm is going to be used for transportation systems such as trucks or railcars, they will either be top-loading or bottom-loading. For ships and barges, marine loading arms (also known as mechanical loading arms - MLA) are used.
These loading arms have swivels joints, which is what enables the piping system to be flexible. The swivel joints typically have, a split flange design to make it easy to swap product seals without having to disassemble the entire swivel joint. The swivel joints are usually made of stainless steel, while the mechanical seals used are polymeric or elastomeric.
In many designs you will find a nitrogen drying system included. This consists of a cavity located between two the product seals into which nitrogen is injected. The purpose of the nitrogen is to prevent the product from being contaminated by moisture from the atmosphere.
For more information on Cryogenic seals check out the following posts from the Advanced EMC Technologies Blog: