Processing / Tech Update

Tech Update: Maintain pumps on your schedule

February 6, 2012
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Like valves, pumps tend to be taken for granted until one fails. And when a pump does fail, taking down a line, the questions are: What will it take to get the pump and the line back up and running? Can the pump be repaired in place? If it has to be removed and replaced, is there a spare immediately on hand? How long will it take to get the line back up? Who will do the work?

While many types of pumps haven’t seen sweeping changes in terms of architecture, new materials choices can extend uptimes and contribute to food safety, and electronic technology is coming online to predict failures and help the maintenance staff schedule preventative maintenance.
In addition, pump suppliers are making maintenance easier by simplifying disassembly/reassembly, providing step-by-step procedures in PDFs and/or video formats including training classes for maintenance technicians, setting up quick parts delivery services or even providing third-party maintenance organizations that can respond quickly to problems.

According to a recent Frost & Sullivan study entitled 360 Degree Analysis of North American Pumps Services Market, pump manufacturers are looking at the service industry as a key player in extending the useful life of pumps, especially as the pump market is in a mature stage with nominal growth projected. 
The study also attributes the relative rise of the service industry to a change in thinking at the shop floor and management level. Plant managers and executives are finally realizing the initial purchase price of a pump is just a small part of the total cost of ownership (TCO). TCO also reflects installation, energy, repair/maintenance and disposal/recycling costs.

Consequently, building the pump right the first time can prevent additional costs and future headaches. “Fluid-o-Tech recommends the use of a pump and motor of sufficient quality and design to avoid pump or motor failure during the service life of the machine in which it’s installed,” says Clyde Smith, technical services manager. “Maintenance costs can often exceed first cost,” he adds. The real challenge for any supplier, says Smith, is making state-of-the-art improvements without affecting cost. Listening attentively to customers and providing application engineering support are additional methods to match pumps and applications so maintenance requirements and repairs are reduced.

Architectural improvements

While most pump manufacturers are not likely to make major architectural changes for customers, processors may specify different polishes or seals depending on application. More important, says Chad Hawkins, Alfa Laval business development manager, the system in question needs to be sized correctly. “One of the big mistakes we frequently see is that people are running pumps in poorly designed systems. For example, pumps are grossly oversized, generating way too much pressure, especially where the pressure is regulated by partially closing a valve.” 

Sometimes it’s the small, incremental advances that keep pumps running longer without a hitch. One example is new technology in diaphragm pumps. “The PTFE over-molded diaphragm is greatly improving diaphragm life in CIP chemical transfer and dosing applications where standard PTFE diaphragms were previously used,” says Kellie Treichel, Graco product marketing manager. “These diaphragms have a fluid-side diaphragm plate over-molded with EPDM [ethylene propylene diene monomer] on the air side and PTFE on the fluid side for chemical resistance. In many cases, these diaphragms last up to five times as long compared to standard PTFE diaphragms, minimizing maintenance costs and decreasing overall pump downtime.”

Similarly, Wilden has introduced a full-stroke, integral piston diaphragm (FSIPD) made from Wilflex, a thermoplastic that has broader chemical compatibility among food/beverage products and withstands typical CIP chemicals, says Wallace Wittkoff, Pump Solutions Group hygienic market director. “In one dairy that pumps ricotta cheese curd, the lifespan of the diaphragms has gone from weeks with food-grade buna to months [with the new diaphragms].” <br><br>
The full-stroke, integral piston version of the diaphragm has the added benefit of being “easy to install,” meaning that when placing the diaphragm on the opposite chamber, the diaphragm does not need to be inverted (which can be difficult without the right tools or strength), according to Wittkoff. With the easy install, the operator doesn’t have to call maintenance for an inspection, manual cleaning or replacement, he adds.

While non-pulsing positive displacement (PD) pumps typically lose performance with wear, Mouvex brand PD pumps are designed with a self-adjusting, internal mechanism that maintains tight clearances throughout the life of the pumping components—typically three to five years or more for semi-abrasive products. Wittkoff recalls a confectionery customer that produces coatings containing abrasive sugar and titanium dioxide that replaced circumferential piston pumps, which had to be rebuilt every three to six months. “With Mouvex, this processor has yet to rebuild or replace worn pumping elements since installing the first pump three years ago. The same is true for over 30 pumps installed since then,” says Wittkoff.

As CIP finds its way into more applications, especially where continuous processing displaces some batch-processing applications, pump suppliers are responding by designing pumps that can handle CIP chemicals. Doug Vogelsmeier, Marlen product line manager, reports CIP is a key part of R&D for current and future pump designs. Pump seals, however, aren’t the only part of pumps needing scrutiny. “We are also reviewing seal material on our electrical enclosures.” In addition, Vogelsmeier reports, “Alignment check test tools have been completed to test alignment of the main auger as it relates to the vane pump coupler.”

The non-metallic, over-molded fluid section components in Graco’s Husky 1050 pump help to eliminate fluid leakage in the air cover/fluid cover joints and between the fluid cover/manifold joints. “These components have a glass-filled polypropylene frame for strength, over-molded with a non-metallic polypropylene, PVDF or conductive polypropylene to handle many extreme chemicals and prevent chemical leaking,” says Treichel.<br><br>
Fristam’s FKL circumferential piston pump was designed to be CIPable, according to Kevin Tyrrell, Fristam Northwest regional sales manager. “Everything—including rotors—stays in for CIP, eliminating downtime, parts damage, reassembly error and wear and tear from repeated rebuilding and contamination.” Cleaning in place improves the overall sanitation process by making it repeatable and eliminating the possibility of contamination from tools and hands. However, Tyrrell notes, CIPable interiors are not the only thing that’s important; the pump’s exterior design should be rounded for maximum cleanability, and processors should have the option of choosing ultra-clean SS gearboxes, drives and motors to alleviate common foaming cleaners issues. In addition, FKL A pumps use bearing isolators instead of lip seals, providing greater protection to the pump bearings in washdown environments.

“MasoSine pumps are capable of being cleaned in place, and we offer various CIP modifications depending upon the product being pumped and the cleaning protocol used,” says Chuck Treutel, Watson-Marlow national sales manager. “MasoSine pumps are certified to 3-A sanitary standards, too. Of course, not all processors utilize CIP, so we need to efficiently meet clean-out-of-place (COP) protocol as well. For COP, sine pumps are a quick and easy technology to disassemble, clean and reassemble on the spot.” The PD pumps use a single shaft and rotor and have very few parts; repairs and overhauls can often be done inline within a few minutes.

Speeding up disassembly/reassembly 

In positive displacement pumps, disassembly for cleaning is as important as the ability to handle fragile products, according to Hawkins. But cleanability, ease of maintenance and other considerations that are important in the purchase of a PD pump might not be as big an issue in the purchase of a centrifugal pump.For sure, a pump repair should not go like the story seepex President Mike Dillon recounts from his earlier days when replacing a conventional molded-to-metal stator in a progressive cavity (PC) pump in a pet food plant. “I had to change the stator on a trial pump that was being used to pump ground-up beef lungs at about 30˚F,” recounts Dillon. “The stator was very slimy on the outside of the tube, and I could not find any way to grip the cylindrical tube. I ended up lying on my side, on the floor in a lab coat, hugging the stator like a greased pig with one leg pushing on the suction housing in an effort to get enough leverage to pull the stator off the rotor.” Fortunately, newly designed PC pumps can prevent a situation like this.

PC pumps have been avoided in many food plants because they are difficult to disassemble, according to Dillon. “While seepex pioneered the CIPable PC pump over 20 years ago, not that many food plants are really devoted to CIP. COP is still the standard in most food plants,” says Dillon. seepex modified its wobble stator design introduced into the industrial process, water treatment and wastewater treatment markets over 10 years ago to fit the needs of the food industry, says Dillon.

“While this is not the first wobble stator pump released for the food industry, the seepex design is much more robust and easier to clean than other designs,” adds Dillon. The stator doesn’t use an “umbrella” design. Plus, the rubber walls are much thicker and resistant to erosion and pressure-induced tearing, which can occur with the umbrella design, according to Dillon. The architecture minimizes any recesses or holding areas in the stator, so cleaning is faster and easier. The 3-A pump is designed with clamp-style connections to make it easy to disassemble. “Replacing the elastomer stator is much less expensive than a bonded-to-metal stator and much easier because the mechanical compression between rotor and stator is significantly lower,” says Dillon.

Regarding disassembly for repairs, pumps should always be designed so no disassembly of the system piping or driver to the rotating components is required, says Mike Austen, The Gorman-Rupp Company general service manager. 
“Repair in place has been possible with pumps that do not need special tools or high forces to work on,” says Wittkoff. “Positive displacement pumps that are self-adjusting for clearances do not need to be shimmed for clearance, like Mouvex technology, are a good example.” With diaphragm pumps, the Wilden hygienic series is mounted on a rotating fixture that rotates out of the way of inlet/outlet piping. This rotation allows for a part being removed or reassembled to be placed in the most ergonomically correct position. For example, while the top manifold is best removed when the pump is vertical, the liquid chamber is best removed and placed back on when the pump is in the horizontal position, according to Wittkoff.

“One important improvement that we’ve made is creating a modular air valve that can easily be removed with just four bolts for repair or replacement,” says Graco’s Treichel. “This allows the pump to stay online without a complete pump removal for maintenance.”
With Fristam FKL pumps, seals are contained within a cartridge, and they can be preassembled and shelved for easy, one-piece replacement. In addition, no housing or pump modification is needed to change the pump from a single seal to a double seal or from an O-ring seal to a mechanical seal. The pump’s split-style gearbox provides quick and easy access to bearings and shafts. “Using simple forcing studs, the gearbox halves can be separated in less than one minute,” says Tyrrell. Once they are separated, only a few bolts need to be loosened; then, the entire shaft, gears and bearings assembly can be removed as one set. Reassembly is just as simple, and no special tools are needed to reinstall the shaft assembly into the gearbox or to join the two gearbox halves, according to Tyrrell.

Condition monitoring 

Some years ago, protecting large motors in fan, compressor and pump applications became practical with the advent of vibration monitoring systems and early data acquisition software. It didn’t take long to realize the savings in replacing bearings in a motor, compressor or pump before they failed.>
“Condition monitoring for the mechanics of the pump and pump motors is now becoming much more reasonable to use in the smaller pump market,” says Jim Leclair, SPX Flow Technology global product manager. “This monitoring will be the next move to increase reliability and energy efficiency.”
Practical methods exist now in turning off pumps in case of a problem. For example, Vogelsmeier reports heat sensors have been added to the hydraulic systems of pumps to stop the units should the oil temperature exceed operating limits.

Mouvex technology doesn’t use mechanical seals, which are normally responsible for high maintenance costs. Instead, it uses a flexing bellows to provide the drive action for pumping. The bellows is double walled with a pressure switch so failure is detected before product leaks out or product is contaminated, reports Wittkoff. Diaphragm pumps such as Wilden have a similar double diaphragm option so if one diaphragm fails, there will still be a backup. The detection system is called the Wil-Gard.
Graco’s DataTrak device has two primary functions: runaway protection and material tracking via cycle count capability. “The runaway protection will stop the pump from over-speeding if the pumped material runs out,” says Treichel. “The DataTrak also allows the user to track the material usage and proactively schedule pump maintenance after the pump reaches a set cycle count. This technology is available on the Husky 1050 pumps.”
Tracking is one way to establish a preventative maintenance program. According to Gorman-Rupp’s Mike Austen, preventative maintenance programs should include monitoring coupling alignment, belts and sheaves alignment and bearing analysis through vibration and temperature, pressure and vacuum gauge readings, and electrical inspections including amperage, voltage and meg-Ohm measurements. 

All this data can be made visible to operators on touch screens. “We have added the ability to have maintenance manually toggle on the output from the touch screen for added diagnostic capability, reducing troubleshooting time,” says Marlen’s Vogelsmeier. “Improvements have been made on the touch screen controls for a step-by-step sequence of assembly or disassembly. This will aid the operator and shorten training time. Additionally, since it is laid out in this step-by-step method, it forces a repair to be done in this sequence—thus, the same steps the same way creates a routine without having to remember it,” adds Vogelsmeier.


Simplifying repairs

For processors that don’t use third-party service companies and still do repairs themselves, pump companies have taken steps to help manage repairs. For example, “The pumps are modular, with as many as 15 rotors and stators that can fit on one ‘power frame’ where the shafts, bearings and seals are identical,” says Dillon. “All seepex pumps have seal housings that meet DIN 24960, so seals are easy to find, inexpensive and generally in stock.”
“Many of our different pump models use the same components,” says Tyrrell. “For example, there are only two seal sizes that fit 25 FPR models.” 
“Mouvex, Wilden and Almatec equipment from the Pump Solutions Group offer set kits of parts that typically have to be replaced at one time,” says Wittkoff. “They come in a ‘flat pack,’ so all parts are visible separately and are easy to keep hung up or in the shelf as a set.”

Fortunately, most pump suppliers are armed with distributor and servicing networks so when an unplanned failure happens, help can be on the way almost immediately.  In addition, many suppliers offer both on-site and off-site training, plus video help to aid in troubleshooting and repairs. With better and affordable sensor technology, expect to see more performance and equipment monitoring in the same box to keep pumps running at their peak, and plan maintenance on a schedule that works for production. 

For more information:


Clyde Smith, Fluid-o-Tech, 860-276-9270, clyde@fluid-o-tech.com
Chad Hawkins, Alfa Laval, 262-605-2600, chad.hawkins@alfalaval.com
Kellie Treichel, Graco, 612-623-6000, ktreichel@graco.com
Wallace Wittkoff, Pump Solutions Group, 502-905-9169, 
wallace.wittkoff@pumpsg.com
Doug Vogelsmeier, Marlen, 913-895-1339, dougv@marlen.com
Kevin Tyrrell, Fristam, 800-841-5001, fristam@fristampumps.com
Michael Dillon, seepex Inc., 937-864-7150, mdillon@seepex.com
Mike Austen, Gorman-Rupp, 419-755-1011, mausten@gormanrupp.com
Chuck Treutel, Watson-Marlow, 608-883-6851, chuck.treutel@wmpg.com
Jim LeClair, SPX Flow Technology, 800-252-5200, jim.leclair@spx.com
Sam Raimond, Fristam Pumps, 608-203-2041, sraimond@fristampumps.com

 

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