What is cryogenic valve -cryogenic ball valve?
- Cryogenic valves typically means the valve will be used in extremely low temperature as -196 ℃ cold applications.But temperature below-40℃ ~ -196℃ all called cryogenic valve. According to different material grade and valve design structure , the cryogenic valves temperate differed like -40℃ low carbon steel, and-100 ℃ stainless steel, and -196℃ stainless steel. Cryogenic valve type include cryogenic ball valve,cryogenic gate valve ,cryogenic globe valve ,cryogenic check valve and cryogenic butterfly valve.
- The cryogenic ball valve is most prevail among the valves for it’s unrestricted flow direction,small fluid resistance, quick cut off and good performance in low temperature.
- What industry and medium does cryogenic valves used?
- ARANCryogenic ball valves designated for safety transportation for processing,storage,shipment and distribution of ethylene,Liquid Nitrogen, Oxygen, LPG, Liquefied Natural Gas (LNG) and other low temperature liquefied gases.
- These media are not only flammable and explosive, but also gasify when heating up or flashing, and their volume expands rapidly during gasification. If the valve that transports these fluids has a closed valve cavity and the structural design is unreasonable, it will cause the valve cavity to exceed pressure, resulting in medium leakage, the medium maybe also toxic, flammable or explosive or even cause valve cracking and accidents.
- ARAN Cryogenic ball valve design feature
- The cryogenic ball valves has the special design structures meet to such service safety use.
- ● The cryogenic valves designed with extended stem and water drip pallet in stem.
- ● Extend stem calculation according to SHELL SPE77/200/BS6364.
- ● Body Relief Structure
- After gasification, the volume of LNG expands to more than 600 times, it leads to the problem of abnormal pressure increase. When the valve is closed, the LNG accumulating in the valve body cavity absorbs a large amount of heat from the surrounding environment quickly.
- Gasification generates a high pressure in the valve body, it destroys the ball and valve seat components, so that the valve cannot work normally.
- Therefore, a one-way valve is added at the inlet end A of the ball to ensure the pressure balance between the cavity and the inlet pipeline and prevent the cavity from abnormally boosting pressure.
- ● Anti-static device
- All LNG medium is flammable and explosive the anti-static device shall be assembled in stem body and ball.
- ● Body and cover middle flange tight seal
- To ensure the sealing reliability of the middle flange under cryogenic conditions, double sealing design is adopted at the middle flange. Sealing structure: The metal wound gasket 304ss+ flexible graphite and lip seal ring .
- ● Fire safe design
- The body and middle flange connection adopts graphite wound gasket and lip seal ring which has double secure sealing and the valve seat sealing also adopts lip sealing ring and flexible graphite sealed structure. When a fire occurs, the lip seals melt and fail, and the 304ss wind graphite and flexible graphite working as main sealing to prevent external leakage.Fig. Middle flange sealing and anti-fire design.
- ARAN manufacture high performance extends stem cryogenic ball valves with cryogenic treatment and test in house lab control. We specifically built the in house lab due to demanding cryogenic valve production needs.Extend stem for cryogenic service ball valves main application fields like Liquified Natual gas (LNG),Liquefied Petroleum Gas (LPG),Ethylnee plants,Low temperature gas pipelines etc.