At least two major sewage grinder pump manufacturers advertise their systems as having UPC/IAPMO listings. There has been some confusion as to what this listing really means.
Submersible pumps are similar to children: They need to be properly fed. When a submersible pump is installed in a manner that does not permit free flow into the eye of the impeller, the pump may not perform as expected.
Most manufacturers employ semi-open impellers in their self priming centrifugal sewage and trash pump designs. While other types of impellers—enclosed, open or recessed—are sometimes used, this type of impeller has a proven field record for clog resistance and high efficiency. Unlike a totally enclosed impeller, the semi-open impeller lacks a front shroud. The impeller face operates in close proximity to an adjustable wear plate.
When a motor is operated on a variable frequency drive, unexpected voltage can be induced on the rotor and shaft. A number of solutions have been employed in order to prevent early bearing failure in motors operated on drives.
When a discussion turns to requirements for “explosion‐proof” pumps, many people rely on word of mouth, past practices or even old wives tales, it seems. The requirements for “explosion‐proof” pumps and systems are not really that difficult to understand, if you are willing to unlearn many of the myths most people take as truths.