Here's propane in an open top bottle at less than -44F.... it's just a liquid and does not evaporate.
https://www.youtube.com/shorts/y-BXHI6yG-g
https://www.youtube.com/shorts/y-BXHI6yG-g
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Rainhill1829
194 likes, 12 comments. "So Cold Outside Propane Ceases to Vaporize (below -42°C or -44°f) Remains Liquid Outside Tank."
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I've put a lot of detail into the posts today and we shouldn't expect the older kids to remember all of it.... the biggest thing I want them to remember today is that there are many thread types you'll run into on a farm and if two things dont fit together, there's probably a good reason for that.
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Screw Threads. There are many profiles of screw threads but the most common is 60degree. What's magical about 60degree thread angle is that the cos of 60 degrees is 0.5. So the depth of a thread is 0.5 on one side , or 1.0 of the diameter. This means that you can calculate the inner diameter of a hole you intend to thread by taking the 1/(number of threads per inch) and subtracting that from the nominal diameter of the bolt.
Here's an example... 1/4-20 thread... major diameter is 1/4inch (0.25"), the threads take up 1/20" (0.05). So 0.25-0.05=0.20. So the pilot hole (minor diameter) should be 0.20inches.
Metric is even easier... M6x1 means the major diameter is 6mm and the thread pitch is 1mm, so 6mm-1mm= 5mm. The pilot drill should be 5mm.
There are variables that machinists apply to change the fitment. Depending on the application you may want a small gap between the bolt threads and nut threads for dirt or grime, or you may want a tight fit. But this is good enough.
Here's an example... 1/4-20 thread... major diameter is 1/4inch (0.25"), the threads take up 1/20" (0.05). So 0.25-0.05=0.20. So the pilot hole (minor diameter) should be 0.20inches.
Metric is even easier... M6x1 means the major diameter is 6mm and the thread pitch is 1mm, so 6mm-1mm= 5mm. The pilot drill should be 5mm.
There are variables that machinists apply to change the fitment. Depending on the application you may want a small gap between the bolt threads and nut threads for dirt or grime, or you may want a tight fit. But this is good enough.
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We also find threads used on pipes. With pipes we want them to fit tighter and tighter as we screw them together. The idea is that if you tighten them enough they won't leak. So these threads are tapered... kinda cone shaped. So when you see NPT (national pipe thread) you know it will be a tapered thread.
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When we are using water, it is ok to depend on the thread itself being a sealing surface. But when it comes to gas lines or refrigerant lines, we use what's called a flare fitting. There's a tool that forces the end of the tubing to flare out and that's the sealing surface. note with these fittings the thread inside the nut is not tapered, its is a straight thread.
Also note that for gas that is breathable like oxygen, the flare fittings use a normal right hand thread. But for gasses we should not breath like LP gas, argon (welding), CO2 (welding) the threads are left hand threads. The turn backwards to a normal nut and bolt.
So if you find a thread that looks odd or screws together backwards let that be a warning that it could be a flammable gas or a poisonous gas line.
Also note that for gas that is breathable like oxygen, the flare fittings use a normal right hand thread. But for gasses we should not breath like LP gas, argon (welding), CO2 (welding) the threads are left hand threads. The turn backwards to a normal nut and bolt.
So if you find a thread that looks odd or screws together backwards let that be a warning that it could be a flammable gas or a poisonous gas line.
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There is one last thread type I want to show you today.... pressurized hydraulic fittings are similar to the flare fittings I just showed you but they have a different angle on the flare. Again, if you find a thread or a fitting that doesn't fit something else, there's a reason for that. Hydraulic connectors have to routinely handle 3000psi 200bar. To make sure that other tubing doesn't explode, engineers designed hydraulic fittings to not work with other connectors.
JIC is an American hydraulic thread type. Joint Industry Counsel specified these connector types in the 1940s for hydraulics used on airplanes. We now use them on most hydraulic cylinders on tractors.
There is a metric version of this called DIN and there is a british version called 60 degree Whitworth Cone (BSP British Standard Pipe). The fun detail about the BSP is that it specifies the diamter in mm and the threads in threads per inch. What fun!
JIC is an American hydraulic thread type. Joint Industry Counsel specified these connector types in the 1940s for hydraulics used on airplanes. We now use them on most hydraulic cylinders on tractors.
There is a metric version of this called DIN and there is a british version called 60 degree Whitworth Cone (BSP British Standard Pipe). The fun detail about the BSP is that it specifies the diamter in mm and the threads in threads per inch. What fun!
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