PCTFE Seals for Cryogenic LNG Applilcation

• Material: PCTFE
• Tensile Strength: 35MPa
• Density: 2.10-2.18
• Elongation at Break: 20-75%
• Temperature Range: -200 to 150 Celcius Degree
• Transport Package: Plywood Case
• Model NO.: PCTFE
• Specification: Sheet length1-400mm, width100-400mm
• Trademark: Hongda
• Origin: Hunan China
• HS Code: 3902900090
• Production Capacity: 100 Tons/Month

Product Description

                                                     
                                  PCTFE/TFM1600/RPTFE Seals for LNG application

 

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.

Polymer seals that can handle cryogenic temperatures are needed anytime LNG is transported or transferred, and can involve complex mechanisms such as valves, swivels, connectors, etc. In this blog post we are going to focus on the challenges specific to MLAs, or marine loading arms.

PCTFE is a fluoropolymer highly appreciated for its properties of very low gas permeability, chemical stability and low-temperature resistance. It is therefore a material of choice in industrial sectors such as aeronautics, cryogenics, and valve equipment manufacturers. The most common trade name is KEL-F but 3M has discontinued the production of KEL-F in 1996 and the Voltalef of Arkema is now the most common.

PCTFE or polychlorotrifluoroethylene is processed by compression molding or extrusion. This high-performance polymer is a fluorinated polymer close to PTFE with an additional chlorine atom, responsible for the low melt index. It is characterized by its high level of tensile strength and creep resistance. PCTFE also has excellent mechanical properties at cryogenic temperatures.

 

Cryogenic Seals:

There are some major challenges when it comes to seals that must operate in cryogenic conditions. The first is the dangerous aspects of working with cryogenic fluids. However, LNG is one of the safer cryogenic materials out there (e.g., it is stored at atmospheric pressure and it not explosive in its liquid state).

It''s also important to make sure that the seal is compatible with the chemicals involved. For example, LNG contains 80% to 99% methane along with various other hydrocarbons and constituents.

Suggested Materials:

There are some commonly chosen polymers for MLA seals, including PTFE, PCTFE, TFM and UHMW PE. These materials have excellent chemical compatibility, low friction and/or dry-running, and good dimensional stability.  Dimensional changes can be accounted for using a spring-energized seal or sizing the seal by accounting for plastic's coefficient of thermal expansion.  Cryogenic seals made using materials like PTFE and its variants or UHMWPE offer a very high strength-to-weight ratio, excellent durability, and self-lubricating properties.

While cryogenic seals for LNG pose an interesting set of issues, there are several polymeric sealing solutions available. By using materials such as low-temperature PTFE or TFM, the major problems faced by cryogenic seals can be overcome.

Hongda supply all these cryogenic seals or polymer material for customers,welcome for your inquiry!