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In a rare move, U.S. President Barack Obama went to Capitol Hill on Wednesday to personally pitch his stimulus plan to House Republicans. They were not impressed.

The plan passed with no problem (244-188). However, not one single Republican gave support to the President’s proposal, some of them stating for the record that they felt the now $819 billion plan contains too much spending and not enough tax cuts.

It is a vote that speaks volumes to the political challenges that await the new President regarding the economy and other issues.

Monday, the debate moves to the Senate and the tax relief provisions of the bill are likely to grow enough to pick up the Republican votes the President has been courting so aggressively.

White House speakers emphasize this is just step one, and indicate that the President is not discouraged. He says he knows it will take longer than a few days to effect change and the Speaker of the House said that “you can’t report the final score of the game when you’re only in the third inning.”

How this impacts the pump industry is still unknown. In the February issue of Pumps & Systems we reported speculation from industry experts and executive association leaders on how a huge portion of this package could dramatically impact infrastructure and the water and wastewater sectors of our industry.  Let us know what you think of these recent developments, and we will continue to give you timely reports.

In a recent conversation with an automation company’s Senior VP of Human Resources, she mentioned how we might see a smaller number of engineers retiring because of the decreased value of retirement savings. She suggested that engineers who planned to retire in the next five years may actually not retire for another eight years or so.

In other words, the country’s economic woes might end up helping the engineering workforce, as it will keep older engineers available to share their knowledge with younger engineers who are just starting in their jobs. We still may not be prepared to fill the jobs that will eventually be vacated by the aging engineering workforce, but at least the economy has given us a little reprieve.

Of course, we can’t neglect this engineering workforce who must work a little longer. They need to be challenged, so they don’t grow weary with their jobs and become less productive. When it comes to the engineering talent shortage, it’s all a delicate balance.

LUBRICATION

Most rotating machinery has some form of lubrication for its bearing systems, figure 2. It may be as simple as a permanently grease-packed, sealed ball bearing or as complicated as a separate lubricating oil pump system complete with cooler, filter, instrumentation, etc. Be sure to verify that any lubrication required has been addressed. Equipment having been in storage may require draining and addition of fresh lubricant or even flushing out of preservatives before fresh lubricant is added. Any gearing present (pump timing gears, reduction drive gears, etc.) should be reviewed for the presence of the correct type and quantity of lubricant. Constant level oilers should be filled to their mark with clean, fresh lubricant of the correct type. Some flexible couplings are grease lubricated and should also be checked. Most electric motors will have grease-lubricated, antifriction bearings that should be checked as well.

Almost all rotary pumps should be able to be turned over by hand. They should generally turn over smoothly, with no catches or uneven rubbing. Very large pumps may need a helper bar but should not be at all difficult to turn. If not, consult pump vendor. Partial disassembly may be advisable to determine the cause of difficulty encountered (foreign material, pipe strain, rust, etc.) before starting.

STARTUP SPARES

With care and planning, startups will generally go smoothly, without significant problems. However, it is prudent to have key spare parts on hand in the event they are needed quickly for correction after some unanticipated problem, minor damage, or need to disassemble a piece of equipment for inspection. For rotary pumps this would normally be a set of shaft seals, gaskets, “o” rings and bearings, frequently available as a minor repair kit. For other rotating equipment, spare bearings, grease and oil seals, gaskets, etc., should be on hand so as to avoid delay in the pump startup. More extensive spares will depend on availability from the vendor, criticality of pump operation, plant practice and, perhaps, other issues specific to the installation. If the startup goes well and the spares are not consumed, they are very appropriate to be held on hand for future routine inspections and service.

RESOURCES

Be sure electric power, steam, cooling water, hot oil, instrumentation power or air or any other auxiliary resources are available and ready before start. Be sure adequate pressure and temperature gages are in place so observations can be made during startup. Without them, you are working blind. Speed indication (tachometers) may also be needed if the drive is not a fixed speed one such as an AC electric motor. If the pump will be handling hot liquid, preheat the pump as necessary so it is not exposed to thermal shock when otherwise hot liquid reaches an ambient temperature pump. Rotary pumps may be somewhat more sensitive to thermal shock due to their close internal running clearances.

Years ago we built, tested and shipped a double ended pump only to have the customer call and report they had a hot thrust bearing. Checking test reports the thrust bearing temperature was normal during test.

Working with the customer they changed the thrust bearing, checked the oil for proper level, viscosity, and contaminates. After restarting the pump the trust bearing temperature was over 220F.

At that point it was decided to return the pump and place it on the test stand. Having all the confidence in the test report and pump, I was surprised to see the thrust bearing temperature rise over 200F.

During the next four days we changed bearings, checked the bearing fits, oil level, viscosity and everything else we could think of. Each time we ran the pump thrust bearing temperature would rise above 200F. Each time we analyzed the bearings they indicated a high axial load in one direction. However, with the pump having a double suction impeller mounted between bearings it was hard to accept the signs of high axial load.

After checking all the possible reasons for bearings running hot except the load on the bearings I decided to revisit the loads on the bearings. The pump was a double suction/double ended pump which should have had a very low axially thrust. The only axial load should have been from slightly different size wear rings which were intentional to keep the rotor from shuttling during operation.

On the way to work the next morning I realized I needed to “Step out of the woods and look at the trees”. In looking at the trees I remembered an old saying in hydraulic design, “high velocity low pressure, and low velocity high pressure.” Appling this to the pump design I realized that if the impeller was not centered in the volute the pressure acting on the sides of the impeller would be different.

Arriving at work I had the pump disassembled, then added some pattern makers clay to each side of the impeller and reassembled the pump. Knowing the clay would tell us the clearance on each side of the impeller we disassembled the pump and measured the clay. To our dismay we found a significant difference between the clearances on each side of the impeller.

After centering the rotor and reassembling the pump, it was back to the test stand. The results were normal thrust bearing temperatures.

Now that we had found and corrected the problem, we needed an explanation for the difference between the original axially setting and the axial setting of the shipped pump.

Our normal procedure after testing was to disassemble each pump, clean and reassemble the pump for shipment. During reassembly of the pump, the assembler misplaced the spacer between the shaft and the thrust bearing, which sets the axial position of the rotor. He simply got another from stock and assembled the pump.

The problem was twofold. First, the assembler should have checked the axial position of the rotor and machined the spacer to the correct length. Second, the spacer should have been designed so the pump could not be assembled without machining the spacer.

To ensure this did not happen in the future, the assembler was made aware of his mistake and the spacer was revised so it had to be machined.

The moral of the story is to make sure the impeller side walls are centered in the volute. Note: Simply pushing the rotor each way in the pump and centering it may not ensure the impeller side walls are centered in the volute.

In our February issue, we feature the impact the new presidential administration’s stimulus package will have on the pump industry, particularly with regard to infrastructure rebuilding in the water and wastewater sectors.

We talked with several “in the loop” industry experts and association leaders who all agree that this package can only mean positive things for pump community.

At press time, Barack Obama had not yet been inaugurated and the details of his economic recovery plan were not public. Therefore, the article is pure speculation—although highly reliable speculation. We are proud to bring you this information.

Here is a taste of what you’ll read in the article:

Facing perhaps the most desolate financial outlook since World War II, U.S. President Barack Obama is expected to unveil an economic-recovery package that could include large investments in energy, education, infrastructure and health care. The amount of stimulus and how it affects the pump industry is yet to be determined.

“As of this time, it is anyone’s guess how big the stimulus package will be, but it will likely be of historic proportion from all the chatter we are hearing on Capitol Hill and in the press—anywhere in the range of $500 billion up to a trillion,” says Dawn Kristof Champney, president of the Water & Wastewater Equipment Manufacturers Association, Inc. (WWEMA). “The only real number I have heard to date is from Congressman James Oberstar who heads the House Transportation and Infrastructure Committee. He is recommending that $9 to $12 billion be included for water and wastewater infrastructure projects.”

Some sources report the package could be upward of $775 billion.

Thanks to pump-zone.com, we have the opportunity to update you daily online and continue to provide more in-depth coverage in print. We plan to cover the stimulus package story closely throughout the year through both mediums. Check my blog daily for timely reports on the progress of the package.

Do you have opinions, theories or further speculation about this package? If so, we have an excellent new forum—PumpConnect—where our readers can blog, network and discuss this and other issues with friends in the industry. We invite you to join us on this completely user-generated space created just for you!  It is the perfect place to visit daily, express your opinions, network with others in the pump community and debate critical industry issues.

 FOUNDATION, ALIGNMENT AND ROTATIONIf horizontal pumps are used, be sure the foundation is level, hold down bolts are tight and grouting, if used, has completely filled the baseplate (no hollows or voids) and has cured. If the pump will be handling liquid above about 150 °F (65 °C) or a steam turbine is used as the driver, an estimate of the centerline growth in height of the hot machine must be made. Shaft to shaft alignment (cold) should incorporate a deliberate, compensating off set, so that alignment is more nearly correct when equipment is up to operating temperature. Coefficients of thermal expansion for common pump case materials are:

Thermal Growth Coefficients (x10^-6)

Material inches/inch/°F mm/mm/°CCast iron 6.0 11.0

Ductile iron 6.6 12.0

Cast steel 6.5 12.1

316 Stainless steel 9.4 17.0

The coefficient is applied to the centerline height of the shafts and the difference in temperature between that at which the unit was aligned and temperature of expected operation. The cold machine should be shimmed high by the above calculated amount.

The purpose on any shaft aligning procedure is to align the centers of the machine shafts with each other, NOT to align the flexible coupling hubs. At temperature, alignment should be within 0.003 inches (0.076 mm) Total Indicator Reading (TIR), both angular and parallel. Consult a good aligning procedure to achieve or verify this degree of precision. The fact that the coupling may be rated to a much greater misalignment capability has nothing to do with the shaft-to-shaft alignment of the equipment. Survival and longevity of the machinery, NOT the coupling, are the objectives. If hot pumps and/or drivers are used, after they are at nominal operating temperature long enough for thermal growth to have stabilized (probably one hour or more), shut down the equipment and verify that alignment is within proscribed limits.

Never rely upon the alignment that was produced where the pump and drive train were assembled. Transportation, lifting and handling as well as foundation irregularities will impact alignment, always in an undesirable direction. Final alignment should be achieved as nearly the last step before actual starting of the pump. If equipment is to be dowelled in place, do so to the pump ONLY after several hours, if not days, of good operation and hot alignment checks.

The use of resilient mounts is sometimes desired to reduce vibration being transmitted into the underlying foundation. If used, such mounts must not be used beneath the pump or driver but between the pump/driver baseplate or bracket and the foundation. The pump and driver must be rigidly aligned, not resiliently aligned, as the resilient mounts will not maintain adequate alignment under torsional reactions from the transmitted torque.

Direction of rotation is critical for most equipment. It is usually indicated by arrow nameplates. Remember that some gearing will reverse rotation from input shaft to output shaft. Most engines and turbines must be purchased for a specific direction of rotation. This is also true of most pumps. Standard AC electric motors are frequently bidirectional; their direction of rotation will depend upon how the power cables are connected. It is normally not possible to predict their direction of rotation before hand. It is recommended that the flexible coupling at the motor shaft be disconnected and the motor momentarily energized (jogged on, then immediately off) to see if its rotation is correct for the rest of the driven equipment. If not, two of the electric power cables will need to have their connections reversed. Verify correct rotation after reversing, if necessary, before re-engaging the flexible coupling.

Check back in a few days for additional content on rotary pump startups.

For more information, contact Jim Brennan at

• Avoiding Problems and Maximizing Operation During Rotary Pump Startups 

  Many pump startups are the culmination of months, if not years, of work designing the process, machine or system; specifying components, instrumentation and protective devices; and reviewing and qualifying suppliers, etc. It is also the most vulnerable time for any pump. This article describes cautions, reviews and inspections that should be conducted before startup to help ensure that all those many gremlins of pumping systems are found out and addressed in time.

  To begin with, thoroughly read the technical manuals and instructions from the pump, driver and all auxiliary equipment suppliers to uncover requirements that may be specific to their equipment design. This is the easiest method to protect the system but is overlooked more often than not.

  PIPES AND VALVES

  Piping and valving installation, figure 1, should probably be considered first. Be sure all required valves have been installed. Verify that none are installed backwards. An absent or reverse-mounted check valve, foot valve or relief valve can cause some very serious damage. Piping should have been inspected during fabrication to ensure that weld bead, weld rod, scale, etc. have been completely removed. Such hard particles can cause catastrophic pump failure if they lodge in the wrong pump clearance. Temporary, if not permanent, pump inlet strainers should be considered if not already present. They should start in a clean condition so that accumulation of dirt can be monitored.

  The piping system should be pressure tested. Avoid imposing on any system component pressures in excess of their design limits. Many pumps can withstand discharge pressure only on their discharge side. Inlet piping systems are frequently suitable only for low pressure. The pressure test medium should be compatible with the components/system be tested. Don’t use water if the system is not a water system. A low-pressure (15 PSIG, 1 Bar g) compressed air test may be adequate to find missing flange gaskets or other obvious leak sources.

  Check and tighten all flange bolts to specified torque. Pump inlet and discharge piping should have been made up from the pump for a distance of perhaps 20 feet (6 meters) to minimize pipe strain on the pump. Piping should be independently supported. Close internal clearance positive displacement rotary pumps do not make very good pipe anchors. When pipe flanges are unbolted from the pump, flange bolts should be able to be installed/removed without forcing piping into position. Additionally, there should be a flange-to-pump gap not exceeding the greater of twice the flange gasket thickness or 1/16 inch (3 mm).

  Positive displacement pumps will normally have a system pressure-relief valve installed from the discharge piping to either the source of the pumped liquid, such as a supply tank, or to the pump inlet piping (a less desirable point due to the potential for temperature build up during relief valve operation). This valve will normally be set slightly higher than the maximum anticipated normal system operating pressure. If possible, verify that it has been properly set. If this cannot be verified, consider adjusting the relief valve to a very low pressure and changing it upward after pump startup. Consult relief valve vendor’s technical data to be sure valve adjustment is done in the correct (to lower pressure) direction.

  Ideally, the entire piping and valve system will be thoroughly flushed to remove all dirt and fabrication debris. This is normally done using a flush pump, not the normal system pump. Strainers and or filters are installed at appropriate locations and their dirt accumulation is monitored until they show no accumulation for a period of 24 hours. Flushing usually uses light, fairly hot (150 °F, 65 °C) oil delivered at flow rates higher than system design. The higher flow rates cause higher liquid velocities within the piping system and are more likely to dislodge debris.

  Some systems will also use vibration equipment to impose mechanical “shaking” on the piping, again to improve dislodging dirt. Very extensive piping systems have been known to still show debris accumulation after 30 days of flushing. Pipeline systems, due to their long distances and relatively huge holding volumes, will frequently use “pigs,” bullet-shaped devices, sometimes equipped with wire bristles, which are propelled ahead of a flush or initial product batch of liquid to scrub debris and dirt from the pipeline inside diameter.

  Before final startup, be sure valves are open or closed as required. Pump inlet and discharge valves are normally left full open. Manual pump bypass valves are also normally left open on startup. An air bleed valve in the discharge piping at a high point near the pump will significantly improve the pump’s ability to self prime. The valve is left open during startup until liquid flows. It is then shut. Be sure to know where this flow will be directed to avoid inadvertent discharge to atmosphere or spillage. Steam turbine steam valving is very important. Turbine startup procedures should be thoroughly reviewed as there are personal injury issues associated with this equipment if started or operated improperly.

  Check back in a few days for additional content on rotary pump startups.

  For more information, contact Jim Brennan at

   

   

  jimb@pumpxpert.com, and visit www.colfaxcorp.com

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We all know there’s an engineering talent shortage. In the United States and the world, there are not enough engineers to meet future demand (especially with the large numbers of engineers planning to retire). 

I heard something recently from a pump recruiting manager that was equally worrisome. Engineers just graduating from college are jumping from job to job after only three to six months of work. Motivated by a higher paycheck, these young engineers sometimes accumulate a resume of five to eight jobs in two years.  

This is a rather troubling result of the talent shortage. Knowing that their skills are in high demand, some young engineers are naming their price and taking advantage of the needs of the companies. This economy may do something to curb this phenomenon, but it’s a trend worth watching over the next few years.