A good piping layout will consider many things: Quantity and size of lines, length of runs, flexibility, maintainability, and expandability (see Figures 400-7 through 400-9). A furnace pipeway typically forms the bar of a T- or L-shaped pipeway system. This layout makes the best possible use of the free space between the furnace and equipment. It is also a practical necessity whenever we deal with more than one furnace or where another furnace is expected in the future. Aside from symmetry, this layout offers great “freedom” in piping, i.e., the ability to solve practically any piping problem with ease and without recourse to expensive design patterns. It also provides excellent possibilities for serving additional furnaces in the future.
It is not advisable to place the furnace so that the pipeway points directly at it (Figure 400-10), even if we are convinced that the plant will never require more than one furnace. This is because branch lines serving equipment should always be normal to the pipeway to which they connect. Pipeways which aim directly at a piece of equipment will have the sequence of their lines dictated by this equipment. This would complicate the design of the pipeway itself immeasurably, since spacing of lines in a pipeway is based on entirely different considerations than the spacing of lines at any piece of equipment. An attempt to make a transition from the sequence of the pipes and their spacing in the pipeway to the order and spacing required for the equipment could only be accomplished by means of costly and complicated pipe configurations.