Line Loss in the Pump System

One of the challenges encountered by many in charge of proper system design and performance is the physical phenomenon of system performance loss as a result of a volume of water passing through a hose. The resistance a hose creates is similar to the resistance ultimately created by the nozzle, but with a lesser effect.

Below is a guide chart for reference within the flow range of Pumptec pumps.

Hose Friction Pressure Loss
(Pressure Drop in PSI per 100FT of Hose with Typical Water Flow Rates)

Line Loss Chart

Understanding this information can prevent under-specifying of pump set and disappointing results.

A situation many find themselves in is when a small plastic diaphragm pump with long hoses on hose reel is expected to provide critical flow and pressure out the nozzle at the end. A pump rated for 3 gpm and 60 psi, used with ⅜” hose cannot offer much performance at the end. According to the chart, the line loss is 50 psi per 100 ft of hose.

The benefit of a Pumptec plunger pump is extended pressure capabilities to overcome the resistance in the hose. For example, a standard Pumptec pump set, 114T-075/M15 (Spray Basic), has a pressure rating of 150 psi to provide desired nozzle performance at the end of long hose runs.

The chart can also be used to maximize system performance. If, for example, the system produces 3 gpm and has 150 capability, and 100 psi is needed at the nozzle the chart can assist. If the hose is 100 ft long, then ⅜” hose is a good choice, but if the hose length is longer then ½” hose would be better.