To quote Larry Bachus, the pump guy, “Every day there are mechanics and operators standing next to pumps without gauges. The operator has absolutely no idea if the pump is healthy or sick. Before long, the pump becomes a high maintenance item.” Why is it that so many pumps go without proper monitoring?
Why Pumps Need Pressure Gauges
A set of digital pressure gauges will tell if a pump is healthy or sick. How? The gauges will show you the pressure differential between the suction nozzle and the discharge. That differential should match the PSI for which the pump was designed.
For example, if the pump was designed for 80 ft. of head, it should be outputting 34.6 PSI (80 ft./2.31=34.6 PSI) above the suction pressure. So if the digital gauge at the suction nozzle reads zero, then the discharge pressure gauge should read 34.6. If the suction gauge reads 25 PSI, the discharge gauge should read 59.6 PSI.
If the discharge pressure is not right, then the pump needs to be adjusted to run optimally. This will prevent all kinds of problems – helping your bearings and mechanical seals last for many years. Before you start to make changes to your pumps, first understand what the pump is doing – and for that you need good pressure gauges.
When It Comes To Pressure Gauges, Digital Is Best
A digital pressure gauge is preferred because it is more accurate and stable. Reading the gauge is unaffected by vibration, and a digital gauge will not need calibration nearly as often. It also helps to remember that plumbing in a valve at the suction and discharge will allow you to use one set of gauges on multiple pumps, so you can enjoy the enhanced reliability and features of a digital gauge without breaking the bank.
Analog pressure gauges, on the other hand, are less accurate and less reliable. The needle and internal gears are dramatically affected by vibration. If left on a vibrating line for too long, the gauge will quickly wear out – requiring either recalibration or replacement.
Reading a needle on an analog pressure gauge contributes to the inaccuracy. If you have a good analog gauge that has an error band of 5% or less, this is magnified by visual error. Not only are you guessing at decimal points, but the angle at which you read the gauge will increase the error band. This is compounded when the needle is vibrating.
Suddenly, the analog gauge that you got for a low price with good-enough accuracy isn’t so accurate anymore.
When a pump is left unmonitored, it soon becomes a high maintenance item. A lot of money is spent trying to fix the pump. Again, to quote the pump guy, “Someone will say, “Maybe we should buy that $50,000 CMM program.” And someone else will say, “Let’s buy that $80,000 vibration analyzer.” I would say, “Why don’t you go buy a set of gauges… and train the operators?””
A good set of digital pressure gauges will prevent unnecessary and expensive maintenance. With proper training, much of which is available online, your operators and mechanics can properly troubleshoot and fix pump issues before they result in pump repair and a loss of production.
Let us know if you have any questions about how digital pressure gauges will help you keep your pumps running.