UL Field Inspections. Yesterday we were greeted at the front door by our UL Inspector for an unannounced field inspectionâ¦surprise! At another facility there might be a cry for alarm, but at Coast Label Company there was no mad scramble, no rush to hide this, or go find that. We just sat him down and asked what he was checking today.
Jet pumps create suction in a rather novel way. The pump is powered by an electric motor that drives an impeller, or centrifugal pump. The impeller moves water, called drive water, from the well through a narrow orifice, or jet, mounted in the housing in front of the impeller.
The main disadvantage is that they use rotation instead of suction to move water, and therefore have almost no suction power. This means that a centrifugal pump must be put under water, or primed, before it will move water. Centrifugal pumps can also develop a phenomenon called âcavitationâ.