harbor freight 2 stage vacuum pump tear down скачать в хорошем качестве

harbor freight 2 stage vacuum pump tear down

This video contains Paid links that gives me a 6% commission if you click and buy any product on that website . Check out my web site http://www.nobox7.com/ Check out my store front https://www.amazon.com/shop/nobox7 Support this channel on Patreon https://www.patreon.com/user?u=3620781 harbor freight 2 stage vacuum pump get a better one hear or the same one http://amzn.to/2BTWr5D or try this model http://amzn.to/2EEJoI5 t is important to understand what vacuum is and how it is measured in order to correctly apply it in the hvacr industry. The dictionary defines vacuum as “a space with nothing in it.” In the real world there is no such place because molecules of various elements are everywhere. It is the density of these molecules within an enclosed space that we measure as pressure. For our purposes, a vacuum is a space where the density of molecules is less than that of the earth’s atmosphere. In other words, a space with a vacuum has less than atmospheric pressure. The inventor of the mercury barometer, Evangelista Torricelli, first measured atmospheric pressure in 1643. A long glass tube with one sealed end was filled and then inverted in a bath of mercury. Torricelli found that at sea level the earth’s atmosphere exerts enough force to support a column of mercury 760 millimeters (29.921 inches) high at a temperature of 32° F. The resulting empty space at the top of the tube was a (nearly) total vacuum. The unit of measurement for vacuum was named for the inventor, and one atmosphere of pressure is now referred to as 760 Torr, a measurement of absolute pressure. If it were possible to achieve a vacuum of zero Torr, we would have a perfect vacuum or zero absolute pressure. When vacuum is measured in inches of mercury it must be remembered that atmospheric pressure (gauge pressure) is the starting point and that the gauge readings are negative numbers. Thus, -29.921 inches Hg is a perfect vacuum. It is not practical to measure a deep vacuum (low absolute pressure) in inches of mercury because the units are so large; it is measured in microns. There are 1,000 microns in a millimeter (Torr) and 25,400 microns in 1 inch of mercury, so the use of this unit makes the measurement of deep vacuum much more precise. Applying vacuum to hvacr Refrigeration and air-conditioning equipment must properly be evacuated prior to charging to prevent unwanted molecules — primarily water vapor — from damaging the system. Moisture in a system can cause freeze-ups in capillary tubing and expansion valves. The natural tendency of moisture to cause corrosion is multiplied when it reacts with certain refrigerants and forms hydrochloric or hydrofluoric acid. Refrigeration oils — especially the newer POE and PAG oils — absorb moisture, and the combination forms what is commonly referred to as sludge. The most practical method for removing these molecules is to connect a high vacuum pump to the system and reduce the absolute internal pressure (vacuum) to less than 1,000 microns. Reducing the pressure lowers the boiling point of water vapor so it can be removed from the system at temperatures below 32° F. If a system is wet, reaching this pressure may take quite some time and require several changes of pump oil due to water vapor contamination. After evacuating, the system must be isolated and the pressure must be maintained at less than 2,000 microns for a reasonable length of time. This ensures that there are no leaks or significant contamination present. Either of these conditions may result in premature system failure and a warranty service call. Understanding th