Talk:Flash point

message: Note that volitle materials like naphthalene which have no liquid phase at 1 bar also have a flash point.  The temperature of the flame from burning liquid is a measure of the exothermisity of the reaction, and so is related, in a complicated way, to the flash point.    — Preceding unsigned comment added by Yellier (talk • contribs) 11:16, 11 August 2011 (UTC)
thread_title: Untitled

message: Flashpoint is also an event that starts a war. (IE: Hitler invading Poland was the flashpoint of WW2). We should fit this in some where. CaptainAmerica 15:46, 20 Jun 2005 (UTC)
replies: text: Done. (211.31.177.90 14:16, 15 October 2005 (UTC)
thread_title:  Other Uses of Flash point 

message: Pzavon, I guess you could give some sort of answer to this and possibly include it somewhere (in short):
is the fact that different vapour concentrations are needed to sustain the burning of the vapour related to the heat being released from the burning vapour? So that a substance with a high enthalpy of combustion would require less vapour concentration, because the heat evolved will sustain the fire even at low concentrations? Or have I not really understood the concept of flash point, proposing this?  Question posted 25 July 2007 by 130.238.197.120 </Small>
:This is far from my specialty, but I would think that is not the case.  The minimum concentration needed to sustain combustion relates to the ease with which the vapor oxidizes, and that is not, I think, directly dependent on temperature (although all chemical reactions are faster at higer temperatures).  The flash point is simply the liquid temperature at which the vapor concentration just above the liquid surface reaches a sufficient concentration to be able to flash, or be ignighted.  Sustained combustion is not a requirement of Flash Point, only that what is there will flash over.  Generally a higher temperature (or vapor concentration) is required to sustain combustion.  Once sustained combustion is established, it is likely that the heat from the combustion reaction will contribute to the continued evaporation of the combustible liquid.  (The is how a candle works.)  Pzavon 01:09, 26 July 2007 (UTC)
thread_title:  Mechanism - involves heat of combustion? 

message: The question I have refers to this caption of the article:
:"Diesel is designed for use in a high-compression engine. Air is compressed until it has been heated above the autoignition temperature of diesel; then the fuel is injected as a high-pressure spray, keeping the fuel-air mix within the flammable limits of diesel. There is no ignition source. Therefore, diesel is required to have a high flash point and a low autoignition temperature."
I understand why a diesel engine needs a low autoignition temperature (no sparkplug & unscavenged, unburnt fuel is imcompressible), but why does it have a higher flashpoint? Once diesel fuel is introduced into the cylinder the intention is for it to burn, rapidly. Doesn't the atomisation of the fuel spray encourage evaporation anyways? I could understand if it is just a byproduct of the manufacturing process (i.e., no consideration due its irrelevance on the operation of the engine), but if it was intentional the reasoning has lost me. Apart from compression and the ignition source, I don't know of any differences between a diesel or a gasoline engine...
I hope someone could clear up the issue here, and if need be on the article itself. LostCause 09:08, 16 August 2007 (UTC)
thread_title:  Question Regarding Diesel vs. Gasoline Section 

message: The Table given does not say whether the flash points given were determined by closed or open cup
137.158.152.206 (talk) 14:44, 13 October 2008 (UTC)
thread_title:  Table of flash points 

message: Anyone want to add a section about how the flash point is found?
Information and diagram ideas can be found here.
FreeT (talk) 00:30, 7 March 2009 (UTC)
thread_title:  New section with diagrams? 

message: changed this to JP-4 as per Wiki on military jet fuel  —Preceding unsigned comment added by 110.175.121.168 (talk) 04:52, 6 March 2011 (UTC)
thread_title:  FP-4 

message: In the Measurement section I found it incorrectly stated, in part (erroneous phrase in italics):
 Closed cup testers normally give lower values for the flash point than open cup (typically 5–10 °C (41–50 °F)) 
In this context, the temperature is being compared (a temperature difference) rather than converted (to a thermometric temperature), and as such "5–10 °C" equals "9–18 °F", rather than the stated value of "41–50 °F". This is a function of the conversion rate alone, rather than the full conversion rate + offset. In a similar sense one would correctly say "5–10 °C equals 5–10 K", rather than incorrectly say "5–10 °C equals 278–283 K" when discussing a Celsius/Kelvin comparison.
YodaWhat (talk) 15:36, 21 December 2011 (UTC)
thread_title:  Temperature Comparison vs Temperature Conversion 

message: I will come back here later and edit to remove marketing information.
--Taquito1 (talk) 13:43, 13 March 2014 (UTC)
thread_title:  Looks like advertising 

message: How high is the flashpoint of 2 stroke oil?
And how does 2 stroke gasoline ignition temperatures differ from regular gasoline?  — Preceding unsigned comment added by 170.55.165.221 (talk) 11:26, 19 April 2018 (UTC)
thread_title:  2stroke oil 

message: I am knowledgeable in the area of flammability of chemical substances. I think this article lacks several pieces of information that it should contain.  1. Flash Point is a measure of hazard. It can be used by firefighting personnel, and those concerned with the safe storage, transportation, or use of the material. 2. Flash Point specifically tests vapor over a specific amount of material, in either an open or closed space. Open space (open cup) testing is problematic in that ventilation is required for lab/test safety, but is undefined procedurally. Closed space (closed cup) testing is problematic since the time to reach vapor equilibrium is undefined (and variable) and yet assumed to hold. In some testing apparatus, the ignition source is inserted by opening the "closed" cover, hence allowing some air to enter and fumes to leave (as well as disturbing the 'head space'). In general, timing of the test is poorly constrained but is clearly important. 2.5 Powders and mists can be explosive but are outside the scope of these methods.3. Few liquids and solids burn in air. Generally, it is the vapor around (above) the liquid/solid that burns, and this depends on the vapor concentration, air composition and pressure, and temperature. (for instance, some chlorinated organics inhibit combustion). 4. With (arguably) few exceptions all organics will burn at a sufficiently high temperature. (Almost all of those that do not burn, instead will decompose (this decomposition may be explosive)).5. Some organic vapors may accumulate to concentrations ABOVE the Upper Explosive Limit (UEL) and will not, in that condition, burn. (Since this requires confinement, this can be a very dangerous situation because disturbances often involve mixing the vapor with air (i.e. opening the container, cooling the space, etc.) 6. The various cups, open, closed, stirred are convenient and (relatively) inexpensive industrial methods and can be used with other information to assess fire risk of the material in many industrial and commercial settings. 7. Most tests are dynamic, temperature rises throughout the test until ignition occurs. An optimal test (IMHO) would be to use such dynamic testing as a "ranging" test and would be followed by holding the material (with stirring) at a temperature of, say, 2 C under the dynamic test for 1 minute and then attempting ignition. If the material fails to ignite, that temperature is less than the ignition point (*not* the autoignition pt.). The highest temperature tested which is "< (tested) ignition temperature" should be reported as the F.P. For some materials, this may not be feasible, since other reactions occur (i.e. changes in the head space air composition, changes in the chemical composition of the test material, formation of a concentration gradient in the bulk (or surface) of the test material, etc.).174.130.49.98 (talk) 15:29, 10 March 2021 (UTC)
replies: text: Looking forward to you editing it as you suggest GRALISTAIR (talk) 17:09, 4 October 2021 (UTC)
thread_title:  comments