Smithco Turf Spraying Guide - Manual (Page 6)

Other pumps less frequently used on turf sprayers are:
 Roller pumps
 Electric diaphragm pumps
 Ceramic piston pumps
 Turbine pumps
B. - HOSE AND HANDGUN SPRAYING
handgun (or hand-nozzle or hand-lance) is used to control and
direct the spray pattern to the ground, shrub or tree. They
must be constructed of long lasting and non-corrosive
materials such as brass, stainless and aluminum
The handgun fits to a hose of any length from the sprayer allowing
operator mobility. The hose should be as short as possible while still
permitting operator mobility.
Liquid looses pressure due to friction as it travels through the hose, from
1 to 3 PSI for each foot (30 cm) of hose length.
Pressure Drop through Various Hose Sizes
Pressure drop in psi (in 10-Ft. length without couplings)
Flow in GPM ¼” I.D. ½” I.D. ¾” I.D. 1” I.D.
0.5 1.4
1.0
1.5 .4
2.0 .6
2.5 .9
3.0 1.2
4.0 2.0
5.0 2.9 .4
6.0 4.0 .6
8.0 .9 .3
10.0 1.4 .4
As you can see, if a sprayer with a low-pressure centrifugal pump is fitted with an excess of ½” hose
(over 100 feet), it will lose at least 20 PSI at a flow rate of 4.0 GPM. Considering that you only start with
around 60 PSI, it can limit your options. At 6.0 GPM, the pressure loss would be over 40 PSI for 100
feet of hose. This also does not take into account pressure loss through the other fittings, solenoids,
etc.
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