What Sanitary Pressure Gauges Can Tell you about your Sanitary Pump

June 10, 2014

Sanitary pumps mated to electric motors are among the most popular pieces of industrial equipment in the sanitary world. While a lot goes into pump selection, motor sizing, and frame type, one component that is often overlooked is instrumentation. One piece of instrumentation that we try to specify with all installations, but not surprisingly see underutilized, are sanitary pressure gauges. Cheap and often overlooked, this post will take a look at how we can use a sanitary pressure gauge to help monitor pump performance.

While sanitary pumps can be intimidating, they really aren’t all that complicated. At the heart of any pump is a rotating shaft with some kind of impeller that utilizes a motor to impart energy into a fluid. Most pump problems, in fact, originate from outside of the pump. Many pump problems result from the system in which they are installed. Be it a clogged strainer down line, a closed valve, or-most commonly- insufficient suction conditions, it’s the system conditions that causes the pump to perform unexpectedly. So how can we use a pressure gauge to alert us to these conditions? Let us explain.

Let’s say a pump is specified to develop 104 ft of head or about 45 psi. That means there should be a differential pressure (discharge minus inlet pressure) of 45 across the pump. So if there is a gauge on the inlet that reads 10 psi, a gauge on the discharge should read 55 psi.

The Anderson EN Series Digital Pressure Gauge Is available with Output Relays

The Anderson EN Series Digital Pressure Gauge is Available with Output Relays

If we aren’t getting the expected differential pressure, this should be a good clue that something is out of whack.  One of the most common conditions that negatively affects sanitary pump performance is starving the pump. Pump starvation, which can result in cavitation and pump damage, is one of the easiest system problems to identify with an inlet pressure gauge. Taking this a step further, digital pressure gauges, such as Anderson instruments sanitary EN series gauge can come with digital relay switches that can be easily incorporated with a VFD to prevent the pump from being run dry or under less than desirable conditions.

The opposite of pump starvation is over pressurization. This can occur if a strainer is clogged or if a valve downstream is closed. The results are over pressurization can be disastrous- resulting in both pump damage (think bent or snapped shafts) and possibly injury to the operator. While this can be combated with an over pressure relief valve, we also recommend using a pressure gauge in these applications. Again in a pump discharge application we can use Anderson’s EN gauge to turn the pump off after pressure reaches a set point and also use the same gauge to record the highest pressure the system experiences, another useful feature when trouble shooting a system.

To conclude, pressure gauges are an essential piece of every new pump application. We can use them to monitor both upstream and downstream process conditions and head of problems before they result in pump damage or injury to operators. For more ideas on how to get the most out of process system, contact a Holland Sales Engineer today.