Wet Well Wastewater Level Measurement
The Problem:
Water treatment facilities need to process raw sewage from residential and industrial customers without
causing spills back into the environment. Any spill presents environmental issues, health hazards, and is
extremely costly to clean up.
The raw sewage, influent, or wastewater initially enters a lift station. The lift station is a wet well that holds
the raw sewage until it moves to the next step of the process, which is the bar screen for primary treatment.
Lift pumps maintain the wastewater level in the wet well. When the wet well level raises to a pre-set value,
the pumps turn on and move the wastewater to the next step of the treatment process. The level in the wet
well is measured by some type of level measurement instrument that communicates with a controller for
the pumps. Many of these level instruments are prone to failure because of the harsh environment.
Fast moving wastewater, introduced into the wells under pressure,
constantly jostles sensors, often forcing them into the sides of the well
with enough force to cause them to malfunction or to fail altogether.
Our Solution: AMETEK PMT’s Model 675 is a submersible level transmitter designed
for these tough wastewater applications. The Model 675 has a 7 lb,
heavy-duty SST protective cage built around a durable 3.5" flush diaphragm
to prevent the unwanted buildup of debris, fats, oils, greases,
or other bio-solids by eliminating the potential gaps in the measurement
area. The durable construction and weight of the
unit eliminates the effects of turbulence in the
wet well transmitter, whether it’s located at the
bottom of the well, or a stand-off. The Model
675’s all 316 stainless steel construction offers
outstanding environmental protection. A
replaceable lower diaphragm seal provides for
longer transmitter life expectancy and serviceability.
The Model 675 is CSA approved for
Intrinsically Safe operations, Class I
Division 1. It has a 4-20 mA output
that can be linked into a controller
for the pumps, or into our Level-
Mate III system.
See the pdf copy of the
application note here.