“Pump Guy” Offers a Real-Life Example of a Day in Consulting
This pump was operating against a partially closed valve for years without anyone knowing there was a problem.
Over the years, I’ve read a number of articles in the popular water/wastewater trade journals – authored by the “Pump Guy” (Larry Backus of Backus Inc). Since he seems to have such simple answers to apparently complex problems, I recently jotted him an email – asking about his recommendations for “tools” for doing a pump survey for a typical client. Here is the dialog:
Dear Larry,
I really always appreciate your articles in the various technical journals in our industry. So practical and so unique in their perspectives.
The article in the August issue of Flow Control refers to the importance of “systems” in looking at “problems” and I agree 100%. Look at the following blog to see the name and the recent article:
http://equipintegration.com/wordpress/
On a related issue regarding pumps…..do you have a list of “recommended tools” for conducting field evaluations of pumps? Such as a vibration meter, an amp meter, watt meter, pressure gage, speed meter and the like? It would be nice to have a suggested list of tools with example manufacturers of the tools to help a person put together a kit.
Don
Hello Don,
Glad you like the Pump Guy articles. I enjoy writing the column.
As for the recommended tools;
I used to operate a pump rebuild shop. We had 3 pick-up trucks loaded with equipment and tools to attend to the process pumps and motors of our clients. We carried amp meters, alignment equipment, vibration meters, gauges, portable cranes, chain hoists, a complete set of air powered tools, lubricants, gaskets, spare bearings and seals, spare nuts and bolts, etc. to disassemble, repair, load, and off-load pumps and parts onto the trucks.
Today, I travel with my laptop, safety glasses and a hard hat. I visit a process plant or power station as a pump consultant. I tell the engineer to install his equipment (vibration meters, flow meters, gauges, amp meters ) on his problematic pumps. I observe. I can tell about his grasp (understanding) of the problem by his available equipment…and his dexterity handling his equipment and managing his men.
I find I am able to analyze most “pump” problems:
1. by observing, listening and talking with the operators and mechanics.
After analyzing the probable pump problem, I find I am able to resolve most pump problems with:
2. a set of pressure gauges (for the suction and discharge nozzles of the pump),
3. a clip-on flowmeter,
4. the pump performance curve, and sometimes
5 an amp meter.
Often the problem is not in the pump, but in the equipment leading to, or away from, the pump.
Last June, a chemical plant in the Caribbean contracted me regarding a critical pump. I was flown 1st class to the chemical plant 3 hours out of Miami, and put into a 5-star tourist hotel suite. The critical pump was vibrating. The bearings were overheating. The pump had been eating seals and bearings for 10-months.
The vibration technician, with his $60-k analyzer, couldn’t isolate and identify the vibrations. The pumped liquid was not really hot. But the axial roller bearing was hot, and the pump was quite noisy. The engineer wanted my opinion on a better mechanical seal and some synthetic lubricant.
I ordered to install 2 pressure gauges on the suction piping. One gauge was installed onto the exit nozzle of the tank being drained by the pump. The other gauge was installed onto the pump suction nozzle. We started the pump and observed the gauges.
The reading on the gauge at the tank exit nozzle didn’t match the elevation in the tank. The differential pressure was inadequate on the two gauges leading into the pump. We drained the tank.
A hard hat was lodged into the exit nozzle of the tank, preventing the free flow of fluid through the pipe leading to the pump.
We removed the hard hat, filled the tank, and started the pump. The pump vibrations and noise went away.
The hard hat had an ID number. The hat had been missing for a year. The hat had been checked-out to a young intern engineer last year who was cycling thru the Safety and Inspection Department. The intern had inspected the tank last year.
As he left the plant, the intern engineer told the guard he had left his hard hat in the cafeteria, or men’s bathroom.
The hard hat was never found, or turned-in to the guard shack.
Oh well!
Later,
Larry Bachus
This pump was plugging once a week and it – eventually – was found to have the incorrect impeller installed at the factory, which only was designed to pass 2” spheres.
Components vs. Systems Approach to Water Equipment
All of us have had the experience of making a change in one part of a network or puzzle and finding that the apparently small change has affected the entire system….often in ways we did not desire. This fact – called systems heuristics – affects many engineering/equipment insertions at water and wastewater plants.
There is an exceptional expert in this field – Draper Kaufman – and he has been kind enough to share some of his presentations with me. My favorite slide from his presentation reads as shown below:
Everything is Connected to Everything Else
- Real life is lived in a complex world where all subsystems overlap and affect each other.
- The common mistake is to deal with one subsystem in isolation - this almost always backfires as other systems respond in unanticipated ways
Belt thickeners are "mini-systems" within treatment facilities.
In our industry – water and wastewater utilities – this awareness is crucial to successful equipment applications. Here are a few examples:
- Installing a centrifuge for dewatering can affect plant performance in the amount of “fines” being returned to the treatment process and subsequent settleability issues.
- Installing a belt press or thickener will bring significant demand for water for spray bars and must be accounted for in systems hydraulics.
- Adding a pump – especially a larger pump – can affect the plant’s electric bill by increasing “demand charge” for the plant and subsequent monthly power costs can be dramatically impacted.
- Converting coarse bubble aeration to fine bubble aeration may reduce power but it can also create settling issues in tanks if the “roll pattern” is not properly accounted for.
A new Water booster pumping station can have a dramatic effect on water utility operations. Shown is a Bellmer Turbodrain, installed at Grafton, Wisconsin.
And, the list goes on and on. Again, it is foolhardy to believe that a change in a component process step does not have secondary implications. Caution is the word!
Don
Best Utilization of Wastewater Equipment Assets
Operators are key to good design and proper maintenance
The Design Engineer and Operators of utilities need to meet often during the engineering phase of a project.
Who is the very best resource for designs of new (or upgrades of old) water/wastewater systems?…of course, the answer is…it depends as to what is meant by “best resource” and at what point in the evolution of a project.
Recently, I was reading an article on pumping station design and the author – a very competent and seasoned engineer/designer – stated that the most crucial element in design can be the operator or operations personnel. How can this be? Well, the truth is that pumping systems are nearly always complex beyond their initial or preliminary needs. Frequently, there are field circumstances which are far beyond the vision or knowledge of the design engineer. And, the knowledge of the operations staff is always crucial to maintenance of pumping stations – both new and upgraded stations.
The author, further, went on to state that operations staff should be involved in at least 3 stages of design (minimum) and – where practical – might be an integral part of the design team at all stages of design.
Pumping Station designs are often complex and involve interrelated systems
Who is better qualified to determine the ability of local staff to do the required maintenance of the pumps and controls equipment? It certainly is not prudent judgment to design a pumping station and – after it is started up – find that no one within 300 miles can maintain the system. Controls, in particular, can be misapplied – even if they are the most efficient in design – if the owner cannot service the controls or cannot depend upon the local service people who normally service his system to do service on new controls.
Likewise, pumping systems can be shown – on paper – to be most efficient and, upon startup, it is found that the owner is not set up to service such pumps (for instance submersible pumps requiring large hoisting equipment). Of what value to the owner is a very sophisticated and efficient pump system if the system cannot be readily serviced locally? An example might be a submersible pumping station where State or local code may require sophisticated setup procedures for maintaining this equipment. In smaller utilities, in particular, it may be that the owner must call upon a neighboring utility or an expensive service provider any time any alarm system is activated. This is a very costly experience for this particular owner – while it may be a routine call or maintenance issue for another utility. “It depends.”
Pumps and Controls for water and wastewater are integrated 'machinery'
Thus, in any pumping system design, begin with a defined teaming relationship with the owner/operators of the installed equipment. And, involve them at crucial milestone meetings along the way. It is with this type of engagement that you can expect a reliable and readily maintained final system…not to mention the “buy in” by the operators who will be maintaining these vital elements in each utility. Good designs begin with the end in mind. And, the “end” is the day-to-day operations and maintenance so crucial to lowest life cycle cost of ownership.
Don Voigt, P.E., M.S.M.E.