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GREENI Member Since: 22 Aug 2010 Location: staffs Posts: 10383 ![]() ![]() |
Nitrogen keeps tyres at a constant temperature, so no excessive wear if they get too hot.
Deemed as cheating in racing, when I worked for a race team, they would often call for every wheel and tyre to for a whole team to be submitted to the tyre people (Michelin in our case) to be held until just 20 minutes before race time...this would be a to small of a window, to get nitrogen in the tyres... Photo from my TCR days. ![]() And on way to race pits ![]() |
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ZeDefender Member Since: 15 Sep 2011 Location: Munich Posts: 4731 ![]() ![]() ![]() |
So it's only the oxygen and CO2 that are responsible for tyre heating - that's really interesting
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ericvv Member Since: 02 Jun 2011 Location: Near the Jet d'Eau Posts: 5816 ![]() ![]() ![]() |
That is basically correct. It is the friction of the oxygen molecules which heats up the tires. Nitrogen is an "inert gas", and will not heat up due to the friction. If you decide to use it, one thing you have to think about. When the tire center will fill your tires with nitrogen, this has to be done in a two step approach. First fill them up with nitrogen to at least 2 bar, and then let all the air/nitrogen mix out again, thereafter fill them again to the required pressure. If you do not do it this way, there will be too much oxygen still remaining in the mix. I have been doing this for more than 15 years already with all cars. The result is that as the nitrogen does not heat up as much as normal air, you have a more stable tire pressure even when driving at higher speeds. You never actually own a Defender. You merely look after it for the next generation.
http://youtu.be/yVRlSsJwD0o https://youtu.be/vmPr3oTHndg https://www.youtube.com/watch?v=_GtzTT9Pdl0 https://www.youtube.com/watch?v=ABqKPz28e6A https://www.youtube.com/watch?v=rLZ49Jce_n0 https://www.youtube.com/watch?v=XvAsz_ilQYU https://www.youtube.com/watch?v=K8tMHiX9lSw https://m.youtube.com/watch?v=dxwjPuHIV7I https://vimeo.com/201482507 https://www.youtube.com/watch?v=ZSixqL0iyHw |
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K9F Member Since: 12 Nov 2009 Location: Bournemouth Posts: 9610 ![]() ![]() ![]() |
All larger and fighter aircraft tyres are inflated using nitrogen due to the constant heat properties, and certain aircraft once the fuel tanks are empty they are purged with nitrogen as it is an inert gas and gets rid of the flamable fumes. If you go through life with your head in the sand....all people will see is an ar5e!!
Treat every day as if it is your last....one day you will be right!! |
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ericvv Member Since: 02 Jun 2011 Location: Near the Jet d'Eau Posts: 5816 ![]() ![]() ![]() |
One more thing about this. Normally tires filled with nitrogen get a green tire valve cap put on, which is the common indicator for nitrogen filled tires. If you know about this, you can easily spot some vehicles who have that, but it still remains a minority. You should not pay too much for this, as today most good tire centers have their own compressors to produce this nitrogen, in the past they had to buy it in big gas bottles. I pay something like 1 max 2€/tire for this. Forgot to mention, nitrogen molecules are also bigger than oxygen molecules, which supposedly gives less tire pressure loss over time. It is a small thing, but in my opionion potentially good, certainly won't hurt
![]() http://youtu.be/yVRlSsJwD0o https://youtu.be/vmPr3oTHndg https://www.youtube.com/watch?v=_GtzTT9Pdl0 https://www.youtube.com/watch?v=ABqKPz28e6A https://www.youtube.com/watch?v=rLZ49Jce_n0 https://www.youtube.com/watch?v=XvAsz_ilQYU https://www.youtube.com/watch?v=K8tMHiX9lSw https://m.youtube.com/watch?v=dxwjPuHIV7I https://vimeo.com/201482507 https://www.youtube.com/watch?v=ZSixqL0iyHw |
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noworries4x4 Member Since: 24 Dec 2010 Location: Newton Abbot Devon Posts: 1195 ![]() ![]() |
Large crane tyres are also filled with nitrogen in an attempt to keep them cooler but running at 16ton an axle they shoud be filled with ice when they turn up to site on a cold day the wheels area a great place to stand and have a coffee. I can vouch that i have had less tyre failures on my Ifor since using it. If everything is under control you are not going fast enough.
Every Day 16 MY Discovery 4 Commercial Workshop and Escort Vehicle Weekends 07MY L322 TDV8 Vogue SE Series 1 80" 3ltr 6cyl with overdrive No Worries 4X4 |
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me@td5.org Member Since: 16 Jan 2011 Location: Warwick Posts: 856 ![]() ![]() |
Fill them with Sulphurhexafluride, that will sort out any heating issues you have.
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noworries4x4 Member Since: 24 Dec 2010 Location: Newton Abbot Devon Posts: 1195 ![]() ![]() |
Go on then for the thickoes umungst the forum whats that then ??? If everything is under control you are not going fast enough. Every Day 16 MY Discovery 4 Commercial Workshop and Escort Vehicle Weekends 07MY L322 TDV8 Vogue SE Series 1 80" 3ltr 6cyl with overdrive No Worries 4X4 |
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GREENI Member Since: 22 Aug 2010 Location: staffs Posts: 10383 ![]() ![]() |
Yeah, tell him
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ZeDefender Member Since: 15 Sep 2011 Location: Munich Posts: 4731 ![]() ![]() ![]() |
I find mixing CO2 and Sulphurhexafluride grows cracking veg in the old polytunnel
![]() But shout it at them in German because life is also terrifying and confusing... |
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TJ101 Member Since: 30 May 2007 Location: Taunton Somerset Posts: 3750 ![]() ![]() ![]() |
A regular thing in motorsport !!
![]() Why you see a lot of rally car crews having to air down at stage starts California F1, 75th 110 "Kermit", 50th Ann V8, 90 V8 Hybrid, 55 Series 1 Main Brian James Trailer Dealer for South West UK |
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ZeDefender Member Since: 15 Sep 2011 Location: Munich Posts: 4731 ![]() ![]() ![]() |
Just thought about it and my beloved Theoben air rifle has a Nitrogen gas chamber - non-reactive, non-heating - makes sense
![]() But shout it at them in German because life is also terrifying and confusing... |
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noworries4x4 Member Since: 24 Dec 2010 Location: Newton Abbot Devon Posts: 1195 ![]() ![]() |
For the thickos just like me i had to look it up
Sulfur hexafluorideFrom Wikipedia, the free encyclopedia Jump to: navigation, search Sulfur hexafluoride IUPAC name[hide]Sulfur hexafluoride Systematic name[hide]Hexafluoro-λ6-sulfane[1] Other names[hide]Elagas Esaflon Sulfur(VI) fluoride Sulfuric fluoride Identifiers CAS number 2551-62-4 Y PubChem 17358 Y ChemSpider 16425 Y UNII WS7LR3I1D6 N EC number 219-854-2 UN number 1080 KEGG D05962 N MeSH Sulfur+hexafluoride ChEBI CHEBI:30496 Y RTECS number WS4900000 ATC code V08DA05 Gmelin Reference 2752 Jmol-3D images Image 1 SMILES [show] FS(F)(F)(F)(F)F InChI [show] InChI=1S/F6S/c1-7(2,3,4,5)6 Y Key: SFZCNBIFKDRMGX-UHFFFAOYSA-N Y Properties Molecular formula F6S Molar mass 146.06 g mol−1 Appearance Colorless, odorless gas Density 6.17 g/l Boiling point -64 °C, 209 K, -83 °F Vapor pressure 2.9 MPa (at 21.1°C) Structure Crystal structure Orthorhombic, oP28 Space group Oh Coordination geometry Orthogonal hexagonal Molecular shape Octahedral Dipole moment 0 D Thermochemistry Std enthalpy of formation ΔfHo298 −1209 kJ·mol−1[2] Standard molar entropy So298 292 J·mol−1·K−1[2] Hazards MSDS External MSDS S-phrases S38 NFPA 704 000 Related compounds Related sulfur fluorides Disulfur decafluoride Sulfur tetrafluoride Related compounds Selenium hexafluoride Sulfuryl fluoride Tellurium hexafluoride N (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox references Sulfur hexafluoride (SF6) is an inorganic, colorless, odorless, and non-flammable greenhouse gas. SF6 has an octahedral geometry, consisting of six fluorine atoms attached to a central sulfur atom. It is a hypervalent molecule. Typical for a nonpolar gas, it is poorly soluble in water but soluble in nonpolar organic solvents. It is generally transported as a liquefied compressed gas. It has a density of 6.12 g/L at sea level conditions, which is considerably higher than the density of air (1.225 g/L). Contents [hide] 1 Synthesis and reactions 2 Applications 2.1 Dielectric medium 2.2 Medical use 2.3 Tracer compound 2.4 Other uses 3 Greenhouse gas 4 Physiological effects and precautions 5 Other properties 6 See also 7 References 8 Further reading 9 External links [edit] Synthesis and reactionsSF6 can be prepared from the elements through exposure of S8 to F2. This was also the method used by the discoverers Henri Moissan and Paul Lebeau in 1901. Some other sulfur fluorides are cogenerated, but these are removed by heating the mixture to disproportionate any S2F10 (which is highly toxic) and then scrubbing the product with NaOH to destroy remaining SF4. There is virtually no reaction chemistry for SF6. A main contribution to the inertness of SF6 is the steric hindrance of the sulfur atom, whereas its heavier group 16 counterparts, such as SeF6 are more reactive than SF6 as a result of less steric hindrance (See hydrolysis example).[3] It does not react with molten sodium, but reacts exothermically with lithium. For example, reactions of SF6 with water to produce sulfuric acid and hydrofluoric acid (a hydrolysis reaction, which would be thermodynamically favourable) does not occur as a result of steric hindrance: SF6 + 4H2O(l) → no reaction [edit] ApplicationsOf the 8,000 tons of SF6 produced per year, most (6,000 tons) is used as a gaseous dielectric medium in the electrical industry, an inert gas for the casting of magnesium, and as an inert filling for insulated glazing windows. [edit] Dielectric mediumSF6 is used in the electrical industry as a gaseous dielectric medium for high-voltage circuit breakers, switchgear, and other electrical equipment, often replacing oil filled circuit breakers (OCBs) that can contain harmful PCBs. SF6 gas under pressure is used as an insulator in gas insulated switchgear (GIS) because it has a much higher dielectric strength than air or dry nitrogen. This property makes it possible to significantly reduce the size of electrical gear. This makes GIS more suitable for certain purposes such as indoor placement, as opposed to air-insulated electrical gear, which takes up considerably more room. Gas-insulated electrical gear is also more resistant to the effects of pollution and climate, as well as being more reliable in long-term operation because of its controlled operating environment. Although most of the decomposition products tend to quickly re-form SF6, arcing or corona can produce disulfur decafluoride (S2F10), a highly toxic gas, with toxicity similar to phosgene. S2F10 was considered a potential chemical warfare agent in World War II because it does not produce lacrimation or skin irritation, thus providing little warning of exposure. SF6 is also commonly encountered as a high voltage dielectric in the high voltage supplies of particle accelerators, such as Van de Graaff generators and Pelletrons and high voltage transmission electron microscopes. [edit] Medical useSF6 is used to provide a tamponade or plug of a retinal hole in retinal detachment repair operations.[4] It is inert in the vitreous chamber[5] and initially doubles its volume in 36 hours before being absorbed in the blood in 10–14 days.[6] SF6 is used as a contrast agent for ultrasound imaging. Sulfur hexafluoride microbubbles are administered in solution through injection into a peripheral vein. These microbubbles enhance the visibility of blood vessels to ultrasound. This application has been utilized to examine the vascularity of tumours.[7] [edit] Tracer compoundSulfur hexafluoride was the tracer gas used in the first roadway air dispersion model calibration; this research program was sponsored by the U.S. Environmental Protection Agency and conducted in Sunnyvale, California on U.S. Highway 101.[8] Gaseous SF6 is used as a tracer gas in short-term experiments of ventilation efficiency in buildings and indoor enclosures, and for determining infiltration rates. Two major factors recommend its use: its concentration can be measured with satisfactory accuracy at very low concentrations, and the Earth's atmosphere has a negligible concentration of SF6. Sulfur hexafluoride was used as a non-toxic test gas in an experiment at St John's Wood tube station in London, United Kingdom on 25 March 2007.[9] The gas was released throughout the station, and monitored as it drifted around. The purpose of the experiment, which had been announced earlier in March by the Secretary of State for Transport Douglas Alexander, was to investigate how toxic gas might spread throughout London Underground stations and buildings during a terrorist attack. It has been used successfully as a tracer in oceanography to study diapycnal mixing and air-sea gas exchange. [edit] Other usesSulfur hexafluoride is also used as a reagent for creating thrust in a closed Rankine-cycle propulsion system, reacting with solid lithium as used in the United States Navy's Mark 50 torpedo. SF6 plasma is also used in the semiconductor industry as an etchant. SF6 breaks down in the plasma into sulfur and fluorine, the fluorine plasma performing the etching.[10] The magnesium industry uses large amounts of SF6 as inert gas to fill casting forms. Sulfur hexafluoride is also used to pressurize waveguides in radar systems. The gas insulates the waveguide preventing internal arcing. The same use of sulfur hexafluoride is applied in transmission waveguides of medical linear accelerators, which are used for delivery of external beam radiotherapy. Sulfur hexafluoride has been used in electrostatic loudspeakers because of its high dielectric strength and high molecular weight. Sulfur hexafluoride has been used to fill tyres of racing cars in professional events due to its non-flammability and high density. Sulfur hexafluoride was used to fill Nike Air bags in all of their shoes from 1990-1996. [edit] Greenhouse gas Mauna Loa sulfur hexafluoride timeseries.According to the Intergovernmental Panel on Climate Change, SF6 is the most potent greenhouse gas that it has evaluated, with a global warming potential of 22,800[11] times that of CO2 when compared over a 100-year period. Measurements of SF6 show that its global average mixing ratio has increased by about 0.2 ppt per year to over 7 ppt.[12] Sulfur hexafluoride is also extremely long-lived, is inert in the troposphere and stratosphere and has an estimated atmospheric lifetime of 800–3200 years.[13] SF6 is very stable (for countries reporting their emissions to the UNFCCC, a GWP of 23,900 for SF6 was suggested at the third Conference of the Parties: GWP used in Kyoto protocol).[14] Average global SF6 concentrations increased by about seven percent per year during the 1980s and 1990s, mostly as the result of its use in the magnesium production industry, and by electrical utilities and electronics manufacturers. Given the low amounts of SF6 released compared to carbon dioxide, its overall contribution to global warming is estimated to be less than 0.2 percent. [15] In Europe, SF6 falls under the F-Gas directive which ban or control its usage for several applications. Since 1 January 2006, SF6 is banned as a tracer gas and in all applications except high-voltage switchgear.[16] [edit] Physiological effects and precautionsAs with all gasses, the density of SF6 affects the resonance frequencies of the vocal tract, thus changing drastically the vocal sound qualities, or timbre, of those who inhale it. On the other hand, it does not affect the vibrations of the vocal folds. The density of sulfur hexafluoride is relatively high at room temperature and pressure due to the gas's large molar mass. Unlike helium, which has a molar mass of about 4 grams/mol and gives the voice a childish and "Donald Duck" quality, SF6 has a molar mass of about 146 g/mol, and the velocity of sound through the gas is 0.44 times the speed of sound in air due to the large inertia of a SF6 molecule. For comparison, the molar mass of air, which is about 80% nitrogen and 20% oxygen, is approximately 30 g/mol. Inhalation of SF6 causes a lowering of the timbre, or frequency of the formants, of the vocal tract, by contrast with inhalation of helium, which raises it.[17] Like helium, sulfur hexafluoride is a non-toxic gas, yet by displacing oxygen in the lungs, it also carries the risk of asphyxia. [edit] Other propertiesThermal conductivity at STP (101.3 kPa and 0 °C) = 12.058 mW/(m.K)[18] Heat capacity at constant pressure (Cp) (101.3 kPa and 21 °C) = 0.097 kJ/(mol.K) Critical temperature: 45.5 °C Critical pressure: 37.59 bar (3.759 MPa)[18] [edit] See alsoSelenium hexafluoride Tellurium hexafluoride Hypervalent molecule Process for Measuring the Degradation of Sulfur Hexafluoride in High-voltage Systems U.S. Patent 4,633,082 Halocarbon—another group of major greenhouse gases [edit] References^ "Sulfur Hexafluoride - PubChem Public Chemical Database". The PubChem Project. USA: National Center for Biotechnology Information. http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=17358. ^ a b Zumdahl, Steven S. (2009). Chemical Principles 6th Ed.. Houghton Mifflin Company. p. A23. ISBN 0-618-94690-X. ^ Shriver, Atkins. Inorganic Chemistry; W. H. Freeman and Company: New York, 2010; pp 409. ^ Daniel A. Brinton, C. P. Wilkinson, George F. Hilton, Retinal detachment: principles and practice Oxford University Press, 2009 ISBN 0-19-533082-X, page 183 ^ Thompson, John T. (2001). "17: Intraocular gases and techniques for air-fluid exchage". In Peyman, Gholam A.; Meffert, Stephen A.; Conway, Mandi D. et al.. Vitreoretinal Surgical Techniques. London: Martin Dunitz. p. 157. ISBN 1-85317-585-4. http://books.google.com/books?id=gEaQ0wiM7JwC&pg=PA157. Retrieved 11 November 2011. ^ Hilton, G. F.; Das, T.; Majji, A. B.; Jalali, S. (1996). "Pneumatic retinopexy: Principles and practice". Indian Journal of Ophthalmology 44 (3): 131–143. PMID 9018990. edit ^ Lassau N, Chami L, Benatsou B, Peronneau P, Roche A (December 2007). "Dynamic contrast-enhanced ultrasonography (DCE-US) with quantification of tumor perfusion: a new diagnostic tool to evaluate the early effects of antiangiogenic treatment". Eur Radiol 17 (Suppl 6): F89–98. doi:10.1007/s10406-007-0233-6. PMID 18376462. ^ C.Michael Hogan, Leda C. Patmore, Richard Venti, Gary Latshaw et al. (1973) Calibration of a line source model for air pollutant dispersal from roadways, ESL Inc., U.S. Environmental Protection Agency Technology Series, Government Printing Office, Washington, DC ^ "'Poison gas' test on Underground". BBC News. 25 March 2007. http://news.bbc.co.uk/1/hi/england/london/6492501.stm. Retrieved 2007-03-31. ^ Y. Tzeng and T.H. Lin. "Dry Etching of Silicon Materials in SF6 Based Plasmas". http://www.eng.auburn.edu/~tzengy/Publicat...lasma.pdf. ^ Intergovernmental Panel on Climate Change, Working Group 1, Climate Change 2007, Chapter 2.10.2. ^ "Mauna Loa and Global SF6". http://www.esrl.noaa.gov/gmd/hats/insitu/cats/conc/mlosf6.html. Retrieved 2011-03-06. ^ "Atmospheric Lifetimes of Long-Lived Halogenated Species". http://www.sciencemag.org/cgi/content/abstract/sci;259/5092/194. ^ "Climate Change 2001: Working Group I: The Scientific Basis". Intergovernmental Panel on Climate Change. 2001. http://www.grida.no/climate/ipcc_tar/wg1/248.htm. Retrieved 2007-03-31. ^ http://powerplantccs.com/blog/2011/03/sf6-...oride.html ^ F-gas and SF6 restrictions ^ "Physics in speech". phys.unsw.edu.au.. http://www.phys.unsw.edu.au/PHYSICS_!/SPEECH_HELIUM/speech.html. Retrieved 2008-07-20. ^ a b "Air Liquide Gas Encyclopedia Sulfur hexafluoride". http://encyclopedia.airliquide.com/Encyclopedia.asp?GasID=34. Retrieved 2008-10-26. [edit] Further readingChristophorou, Loucas G., Isidor Sauers, ed. (1991). Gaseous Dielectrics VI. Plenum Press. ISBN 0-306-43894-1. Holleman, A. F.; Wiberg, E. Inorganic Chemistry Academic Press: San Diego, 2001. ISBN 0-12-352651-5. Khalifa, Mohammad (1990). High-Voltage Engineering: Theory and Practice. New York: Marcel Dekker. ISBN 0-8247-8128-7. OCLC 20595838. Maller, V. N.; Naidu, M. S. (1981). Advantages in High Voltage Insulation and Arc Interruption in SF6 and Vacuum. Oxford; New York: Pergamon Press. ISBN 0-08-024726-1. OCLC 7866855. SF6 Reduction Partnership for Electric Power Systems [edit] External linksFluoride and compounds fact sheet— National Pollutant Inventory High GWP Gases and Climate Change from the U.S. EPA website International Conference on SF6 and the Environment (related archive) [show]v · t · e Hexafluorides Known hexafluorides Chalcogen hexafluorides SF6 · SeF6 · TeF6 · PoF6 Noble gas hexafluorides XeF6 Transition metal hexafluorides MoF6 · TcF6 · RuF6 · RhF6 · WF6 · ReF6 · OsF6 · IrF6 · PtF6 Actinide hexafluorides UF6 · NpF6 · PuF6 Predicted hexafluorides Noble gas hexafluorides KrF6 · RnF6 Transition metal hexafluorides CrF6 · PdF6 Actinide hexafluorides AmF6 [show]v · t · e Contrast media (V08) If everything is under control you are not going fast enough. Every Day 16 MY Discovery 4 Commercial Workshop and Escort Vehicle Weekends 07MY L322 TDV8 Vogue SE Series 1 80" 3ltr 6cyl with overdrive No Worries 4X4 |
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ericvv Member Since: 02 Jun 2011 Location: Near the Jet d'Eau Posts: 5816 ![]() ![]() ![]() |
![]() ![]() http://youtu.be/yVRlSsJwD0o https://youtu.be/vmPr3oTHndg https://www.youtube.com/watch?v=_GtzTT9Pdl0 https://www.youtube.com/watch?v=ABqKPz28e6A https://www.youtube.com/watch?v=rLZ49Jce_n0 https://www.youtube.com/watch?v=XvAsz_ilQYU https://www.youtube.com/watch?v=K8tMHiX9lSw https://m.youtube.com/watch?v=dxwjPuHIV7I https://vimeo.com/201482507 https://www.youtube.com/watch?v=ZSixqL0iyHw |
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