Safety Precaution Thread when working with Phasechange cooling.

[jinu117]

Since there is a lot of tribal knowledge with no good compilation I decided to start on post to hopefully compile those into one thread. Whatever you can think of, please contribute and I will update this post to reflect it.
Thread will be updated with contributions.

1. Brazing Safety
   
   1. General Safety
      
      • Read the instruction of your tool. If there is conflict with guides here, than follow tool manufacturer's suggestion and let us know.
      • Look at the direction you will have to braze and see if there is any combustible parts on the line of torch. If there is, use some type of heatshielding material to prevent fire.
      • Tanks should not be subjected to shock. Find safe and secure place to store the tanks.
      • Work in well ventilated area. In case of leak, this helps making sure that local cloud of gas doesn't form. Which could be very explosive when ignited.
      • Prepare your work pieces in advance with consideration for ease of brazing. Harder the brazing angle is, more chances you will do something that is unsafe to make it work.
      • Keep emergency fire extinguisher handy in area near your brazing
      • Use proper attire that isn't likely to get caught with part brazing, or can hold melted solder in, or can burn easily (wool comes to mind). Use safety protection such as gloves, glasses, etc.
      • When possible, braze outdoors. Make sure the light level is bright enough to see the work, but dim enough to see the flame.
      • Always have someone else ready to take care of any accidents that can happen
   2. Mapp/Propane Torch
      
      • Always shut off the valve, switch after use.
      • Make sure there is no leak on joint. Soapy water can be used to test.
   3. Oxy Acetylene Torch
      
      • Always shut off both acetylene tank and oxygen tank after use.
      • Test each time you replace tanks for leaks and tight seals. Also test it weekly to make sure.
      • While in use, keep the acetylene tank ranch in the knob so you can do emergency cut off without having to search for it.
      • Please, please, spend money and buy the proper fitting flash back arrestor. Some can be attached on regulator side, some can be attached on torch side.
      • There was a debate on how to light the torch. My manufacturer's recommendation and what i do is crack it open on acetylene side first, light it up, than turn oxygen. The other way to cut off the flame.
      • Keep the tip clean. It not only helps with better flame for use, but also less chance of sudden cut off of flame when you get too close to work piece (which really shouldn't happen)
2. Combustible Refrigerant Safety
3. General Refrigerant Safety
   
   • Always put a cap back on when done using refrigerant. Your dog, your kid, or yourself can accidentally turn the valve and let refrigerant out. You can get frost bite, suffocate, or all together lose oxygen in your blood stream with any refrigerant.
4. Charging Safety and when you start up system.
   
   • When leak testing, only go up to weakest rated pressure of component you have. Use inert gas such as Nitrogen, Argon.
   • When charging the second stage of a cascade, always static charge. Since the temperature of the second stage is very low when running, and pressure is proportional to volume and temperature, when temperature increases, so will the pressure in the system. This means that while the pressure in the second stage may be fine when running, the pressure can rise to an unnacceptable level when the system warms up, creating a potentially dangerous situation. This goes double for 3rd, 4th, or Nth stages.
   • When starting up a system for the first time, make sure that if something explodes, catches fire, etc. that you have a way to turn it off quickly and try to put it where it can't damage anything. Test outdoors if you must.
   • On high pressurized gas, take it serious and always use at least high pressure cut off valves (hint, cascade and autocascade). Also nice to have will be high pressure relief valve below or around 400psi. Somewhere in discharge line for sure. --> If there is a good reason for exact location... please let us know.
   • Expansion tanks while useful in controling pressure if they are not properly constructed they will turn into a bomb. Please use appropirately constructed or commercial one.
5. Electrical Safety
   
   • Always refer to schematic diagrams before attempting to wire a compressor. If no schematic is available, and you are not 100% sure of the configuration, it is better to ask than to to hook it up wrong. The capacitors used in these systems can be fairly powerful, and can explode, releasing carcinogens and dangerous chemicals, if used incorrectly. Always insulate all connections. Heat shrink tubing is usually preferrable, but electrical tape and liquid electrical tape will also work. Make sure all mechanical connections are snug. It doesn't hurt to solder, even if you're using the appropriate connectors. Make sure the compressor housing is grounded to both the wall and the chassis if possible. Always use, at bare minimum, a thermal overload relay
   • Making a load tester out of a few resistors and attaching it to mains voltage is very dangerous. Especially that it is then frozen. Use an isolating transformer and a fused line. Better still use a low voltage supply (<50Vac).