Refrigeration Piping

Refrigeration Piping 

probably the  first skill that any refrigeration apprentice mechanic learns is to make a soldered joint, and running piping is so common a proper performance of a system is overlooked. It would seem elementary  in any piping system  that what goes in one end of a pipe  must come out the other, but on a system with  improper piping, it is not uncommmon  for a serviceman  to add gallons of oil to a system, and it may seemingly disappear without a trace. It is of course lying on the bottom of the tubing in  the  system, usually in the evaporator or suction line. When the piping og operating condition is corrected, theoil will return and those same gallons of oil must be removed.

Refrigeration piping involver extremely complex  relationships in the flow  of refrigerant and oil.Fiuid flow is the name given in mechanical engineering to the study of the flow of any fluid, whether it might be a gas or a liquid, and the inter-relationship of velocity, pressure, friction, density, viscosity, and the work required to cause the flow.these relationships evolve into long mathematical equations which form the basis for the fan laws which govern fan performance, and the pressure drop tables for flow through  piping. But 99% of the theories in fluid flow  textbooks deal with the flow of one homogenous fluid, adn there is seldom even a mention of a combination flow of liquid, gas, and oil such as occurs in any refrigeration system. Because of its changing nature, such  flow mathematical equation, and practically the entire working knowledge of refrigeration piping is based on practical experience and test data.As a result, the general type of  gas and  liquid  flow that must  be maintained to avoid problems is known, but seldom is there one exact answer to any problem.