How can you diagnose and repair issues with your plant's pumps?

Usually first to the scene and first to spot the difference is the field operator. By maintaining regular beat walk, his eyes and ears get used to a standard performance, noise, appearance etc. Whenever abnormality sets in, it is important to know, that the failure (of some component) already happened.

Field operator are first line of Defence for noticing any onset of abnormality, good and pro-active shop floor working staff is the real strength for any organisation to succeed.

Actually we use 3senses to check any mechanical components either its working good or bad.? 1.Visual 2.Hearing 3.Touching. Sometimes we need to repair and sometimes we replaced pumps.

The most common issue of pumps which is faced by all of the process industries, is "Cavitation". And the culprit is the blockage of the inlet filter. Sooner or later the impeller gets damaged over time due to pitting. As the process is designed to keep the equipment running in an efficient and clean way, the filter will choke eventually and the pump's performance will go down slowly with time.

It is said that any rotating equipment will complaint for its abnormalities if someone is is habitual to listen it. Like if operator heard abnormal sound or high vibration, it means that the equipment wants to convey it's problem to him that it need some attention and get it corrected. The same ways as our body gives pain signal if something is wrong.

Blockage and clogging can be helpful once the sample is taken and analysed for e.g. X-RAY spectrometer to find out the composition. It can possibly be other material contamination (catalyst, catalyst fines, rust, abrasion products, sediments, resins (some oils tend to polymerise), etc. Upon opening, it is also inevitable to check for any scratches or missing or loose parts (after pump is disassembled, evidence is lost). Usually You look for something missing that should be there or You find something that should not be present :)

Pump problems, motor problems, most any type of problem can be solved in a logical, simple, and methodical manner. I have found that the first place to look for the cause is what changed since it was running properly(was a seal changed, was piping rerouted, are the operating conditions different, etc.). Once you are able to find that information, there is a plethora of available data such as oil, lubricants, vibrations,etc. that can pinpoint the problems. Rest assured, it is probably not a new problem or phenomenon, there are is only a limited number of ways a pump can fail. This developing a fault tree of these failure modes can make diagnosis more efficient and expedient.

In our cases, these helped: - changing seal type (bellows compensator removal - because the pump was not a hot one) - extra cooling circuit for seal oil / lube oil - hydraulics adjustment (basically new cartridge (10 stage cetrifugal pump)) - BEP point adjustment (the original design was way overdesigned - SLOWER HEATING-UP (feed pump, operating temp. ca. 290°C, heat-up is part of the pre-start-up preparation procedure) - slower heat-up helped save us the seal (seals used to break every other time we started-up the pump) - Variable speed drive installation (where applicable, it can even pay off on electricity savings) - BEP is achievable easier - installing pressure controller on a "balance line" (connector between suction and discharge)

The very first and obvious (though usually stepped upon only after a problem occurrs), is to check operating parameters and quality against the pump design. Once all parameters are checked, the solution is to go from the worst impact and easiest achievable (low-hanging fruit). Deal with it. Easier to change operational parameters than hardware.

The best way how to cope with pump problems is to avoid them. Whether with proper design and hardware, operational parameters and process material quality or via predictive and preventive maintenance. I know, nobody likes spending before failure. However, reactive maintenance is ALWAYS worse and much more expensive than a preventive one.