 When we quantify frictional head losses in internal flow, we sort them into two categories. First, major losses, sometimes just referred to as friction losses, which represent the losses associated with friction along straight lengths of pipe. The other type is minor losses, which are associated with anything else. These are usually points of transition, the pipe changing area or changing direction, going through elbows, bends, or other fittings, especially valves. These minor losses are referred to by what we call their minor loss coefficient, represented here with the letter K. In practice, you could probably consult the manufacturer for a published loss coefficient or you could determine the loss coefficient yourself with a simple flow test. For our purposes here, we will be using the charts and graphs of general loss coefficients available in section 6.9 of our textbook. Those charts and graphs give loss coefficients based on some of the physical characteristics of the fitting in question.