ABSTRACT
A city water distribution system has valves and laterals at frequent intervals, and an approximation of minor loss would have to be made to determine its significance. Determination of minor head loss is simple and straightforward, and a standard nomograph in common use. In pumping operations, it is common practice to control flow rate by partially closing a valve on the pump discharge, increasing the minor head loss, and restricting the flow. Larger diameter fittings yield larger equivalent lengths of straight pipe. This seems to contradict calculations for friction head loss, but the attempt with this nomograph is to keep the head loss value for a particular fitting the same no matter what the size. There are a few minor losses which may be expressed in terms of Velocity Head. These have been worked out by experimentation and measurement, and are useful in calculations where Daniel Bernoulli's Theorem is in use and a Velocity Head value is readily at hand.
