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.
An example of a non-positive pump is a centrifugal pump. This type of pump will not pump gases and therefore requires a primer. Ejector Pumps These types of pumps do not use either mechanical pistons or plungers to increase or decrease the pressure but use a fast moving jet of liquid or gas to do the same job. This jet is called a propellant. The ejector pump uses a venture effect within the throat of the pump. At the throat an area of low pressure is created by the fast moving propellant, any movement outside this area being at a higher pressure will flow into the pump. This fluid and the propellant are discharged at the outlet.