Environmental Engineering Reference
In-Depth Information
Check
valve
Gate
valve
Union
Lateral
Cap
Elbow
Te e
fitting
45° elbow
Coupling
Check
valve
Reduced
90° elbow
(turned down)
figure 4.1 Various components in a single-line piping diagram.
For wastewater operators, a familiar example of a piping system
is the network of sodium hypochlorite pipes in treatment plants that
use this chemical for disinfection and other purposes. The whole group
of components—pipes, fittings, and valves—working together for one
purpose makes up a
system
. This particular system has a definite pur-
pose—to carry sodium hypochlorite and distribute it, conveying it to
point of application.
Note:
This chapter is concerned only with the piping system used to
circulate the chemical, not with the hypochlorination equipment itself.
Our concern begins where the chemical outlet is connected to the stor-
age tank and continues to the point where the pipe is connected to the
point of application. The piping, fittings, and valves of the hypochlorina-
tion pipeline (and others) are important to us. Gate, needle, pressure-
relief, air-and-vacuum relief, diaphragm, pinch butterfly, check, rotary,
and globe valves; traps; expansion joints; plugs; elbows; tee fittings; cou-
plings; reducers; laterals; caps; and other fittings help ensure the effec-
tive flow of fluids through the lines. Tracing a piping system through a
plant site will reveal many of them (see Figure 4.1). They are important
because they are directly related to the operation of the system. Piping
system maintenance is concerned with keeping the system functioning
properly, and to function properly piping systems must be kept closed
and leakproof.
Note:
Figure 4.1 shows a single-line diagram that is similar to an electri-
cal schematic. It uses symbols for all the diagram components. A dou-
ble-line diagram (not shown here) is a pictorial view of the pipe, joints,
valves, and other major components similar to an electrical wiring dia-
gram, instead of an electrical schematic.
