Selection and protectionof Pump stations

Prefabricated vertical turbine pump station by Pumping Systems, Inc.

The Middle East crisis has remindedus how dependent we are on peopleand things beyond our control. It has

made us realize how rising energy coststhreaten our budgets at work and at home.Finally, it motivates us to take steps toregain at least some control over complextechnologies that affect our livelihood.

For the golf course superintendent andmanagers of other large turf areas, theirrigation system is one of the most compli-cated mechanisms required to do their job.They are highly dependent upon reliableand consistent delivery of water to turf andother living plants. Without irrigation,maintenance of golf courses and athleticfacilities would be impossible.

At the heart of all large irrigation sys-tems is the pump station. Like oil, we toofrequently take for granted that it will al-ways be there when needed and understateour dependence on it. Instead our attentionhas been directed more toward innovationsin irrigation controls, advancements in

sprinkler heads, and even weather stations.In the attempt to keep golf courses up-to-date and competitive in both design andmaintenance, we have favored the accesso-ries over the basic hardware that makesirrigation possible.

Rising energy prices may bring superin-tendents back to the basics as the cost ofinefficient pump stations is magnified in thecoming months. Electricity wasted to runpumps below their peak efficiency will addup quickly to cost golf courses thousandsof dollars. Many superintendents will get ajolt when they open their electric bills.

At the same time, the golf industry hasbeen hit by a shortage of potable water forirrigation. More and more irrigation sys-tems are operating with lower quality waterthat threatens the performance of pumpstations and many other components. Putit all together and you get the message thatthis winter is a good time to reevaluate yourentire irrigation system - starting with thepump station.

"Pump station efficiency depends uponmany things beside the pump," states Car-roll Childers, president of Carroll ChildersCo. in Houston, TX. "Ninety percent ofwhat people put on pump stations is thereto compensate for flaws in the design ofother parts of the irrigation system."Widely fluctuating flow rates in irrigationschedules, inconsistencies in water supplyand quality at the source, inadequate con-sideration of elevation changes in design,and any changes made in heads or zonesafter installation all affect the demandplaced on the pumps.

"A pump is most efficient at one pointon its curve/'Childers points out. The curvehe is talking about is a graph of the energyconsumed by the pump motor at differentrpm. Running the pump constantly at peakrpm uses the least amount of electricity pergallon of water. If it pumps 500 gallons perminute (gpm) at peak rpm, then the demandfor water by the irrigation zones should bedesigned at 500 gpm to achieve maximumefficiency. Since golf course irrigation sys-tems generally require from 800 to 2,500gpm, a series of pumps are linked togetherto meet demand.

While a conventional pump running ata fixed speed has one point of maximumefficiency, a pump designed to run at differ-ent speeds has many curves and manydifferent efficiency points, says GordonAmmon of Watertronics in Elm Grove, WI.This is the purpose of a variable frequencydrive (VFD). It allows the pump to run atpeak efficiency at any flow. VFD only drawsas much energy as necessary to supply thedemanded flow. It also replaces the hydrau-lic valve which requires an eight to ten psipressure drop. Therefore, less energy isrequired to produce the same flow of waterat the same pressure at the sprinkler.

The extra cost of controls for VFD isoffset by energy savings when water de-mand fluctuates. VFD protects the pumps

12 Golf&sportsTURF

from working harder than required to meetdemand.

Ammon adds that VFD also helps pro-tect pipe and other components from dam-age by severe pulsing when demandfluctuates from one zone to another. Hebelieves that the growing use of effluentwater for irrigation increases the chance formalfunction of hydraulically-actuated pres-sure regulating valves.

Watertronics offers an electrically-actu-ated pressure regulating valve for its pre-fabricated stations. "The workingcomponents of our valve are not exposedto water," says Ammon. "Our valves havea maximum full flow pressure drop of lessthan one psi. This low friction loss trans-lates to less required work by the pumpstations. We use a flow sensor and pressuretransducer that measure rates of change inincrements of time. This information is fedback into a controller, which in turn adjuststhe valve to prevent pulsing."

Hydraulically-activated pressure reduc-ing valves are most common, according toDoug Verhuel with Pumping Systems, Inc.,of Dallas. TX. "Variable frequency driveaccomplishes essentially the same thing bycontrolling pressure and flow," he states."A properly designed pump station in-cludes a downstream relief valve to keeppressure from reaching damaging levels."

"It's like insurance," Childers explains."How much do you need? Backup protec-tion costs money and increases the com-plexity of the station. The way to savemoney is by designing the pump station tofit the irrigation system in the first place. Ifyou make changes in the irrigation system,then you also need to consider adjustmentsin the pump station."

However, a superintendent or irrigationmanager may not be totally aware of somechanges that affect the performance of hisirrigation system and pumping station. Oneprincipal culprit is water quality. Debris,

Watertronics pump station.

particulate matter, or algae carried into thesystem with the water can plug screens,valves, or heads rapidly.

In addition to wear on pump compo-nents, foreign material can reduce or blockthe flow of water during delivery. Whenflow drops below design levels, the effi-ciency of the pumps is reduced. Witnessingplant stress and not being aware of block-age, the superintendent instructs his irriga-tion manager to lengthen cycle times. Thiscompounds inefficiency at the pump sta-tion.

"Most superintendents have so manyother fires to put out that they don't realizethere is a problem with their pump stationuntil something breaks," says Bob Whalen,sales manager of Western Pumping Sys-tems in Chandler, AZ."The pump station isan alien device with a bunch of controlpanels, valves, and relays. Frequently, aproblem isn't obvious until the power billarrives. I know of a case where a stuck valvekept two pumps running for part of amonth. The power bill was $6,000 higherthan expected!"

To assist the superintendent and irriga-tion manager, the company created a devicethat records energy, pressure, and flow.This data can be fed into a personal com-puter with a program that calculates pumpefficiency. Called the Data Logger, the trou-bleshooting device informs the superinten-dent when the pump is not runningproperly. "The Data Logger software iswritten for the superintendent," saysWhalen. "It explains, in terms he can un-

derstand, what problems exist and whatadjustments are necessary."

Poor-quality water is a problem facing agrowing number of golf course superinten-dents. Fortunately there are ways to filterwater both upstream and downstream ofthe pump station. Upstream filters protectthe pump from abrasive materials. Down-stream filters remove finer particles andorganic matter that can plug valves,screens, and drip emitters.

The ideal situation would be to filterwater before it enters the pumps. However,there are practical limitations to upstreamfiltration. Any device that restricts waterfrom entering a pump can cause severedamage due to cavitation.

"A major point of concern is whether toput the filters before the pumps or after,"points out Isaac Orlans, president of AmiadUSA in Van Nuys, CA. "If there is any typeof malfunction with a filter system [up-stream], the pump can be badly damagedfor lack of water. On the other hand, if thefilter is installed after the pump and itmalfunctions, the irrigation system mightsuffer for a few hours. But no loss of amajor capital investment like pumps willhappen. From our experience, if the intakehas been built and located properly, thereis only need for very coarse filtration beforethe pumping station."

To avoid damage to pumps, most manu-facturers suggest filtration only for debrisor coarse particles ahead of the pump.Fixed screen filters are common. The draw-

continued on page 14

November, 1990 13

Pump Stationscontinued from page 13

back with fixed screen filters in cases ofdebris-laden water, such as lakes and mov-ing streams or rivers, is they may requireperiodic cleaning. The intake and screenare generally submerged to avoid surfacedebris and algae. Cleaning or changing thescreen may not be a simple task.

The intake and screen should be largeenough so that fish can swim away from thesuction, advises Childers. Excessive suctionalso encourages rapid buildup of debris onthe screen.

When a river or stream is the watersource, it is difficult to locate the intake ina place free of debris. In such cases, self-cleaning intake filters are recommended.The Plum Creek filter by Claude LavalCorp., of Fresno, CA, uses jets of water tobackwash a cylindrical screen as it rotates.The jets should be positioned in the samedirection as the current of the river.

Like most filters, the self-cleaning screensacrifices a small amount of flow to do itsjob, explains Randy Delenikos, marketingmanager for the company. "A small per-centage of the flow runs back to the jets toclean the screen. It may take 30 gallons outof 900 gpm, Units range in capacity from100 to 4,800 gpm, The screens range in sizefrom ten to 30 mesh."

Sand IScentrifugally

separatedtromwate-and tossed

to perimeter01 chamber

Sand- free water IS drawnto cerser ot seoaratorand up lhrough vertexoutlet 10 pump's suction

Pump Protection Separator by Lakos.

14 Golf& sportsTURF

Plum Creek filter uses jets of water to backwash intake screen.

If the water source is a well, there maybe a chance of sand in the water. "b: prop-erly drilled well should not produce sand,"Childers remarks. "If it does, then you needto realize that bigger problems may becoming. As the sand is removed at the baseof the well, a cavity is created that couldeventually collapse."

One method of protecting the pumpfrom sand is to run the water into a reser-voir first. Sand will settle out before thewater enters the intake. Childers cautionsthat a wet pit is not designed to removeparticulate matter like sand.

A second option has been developed byLakos, a division of Claude Laval Corp. ThePump Protection Separator removescoarse sand by centrifugal force. The sepa-rator, placed in the well hole, redeposits thesand back into the well. For the separatorto work effectively, the water must be main-tained at a certain velocity. Delenikos saysthe separator does not affect flow, but doescreate a loss in pressure of five to ten psi.

The big challenge today is making efflu-ent suitable for landscape and turf irriga-tion. This water has been partially treatedby municipal agencies or private institu-tions to remove solids and begin the pro-cess of bacterial decomposition ofsuspended material. When received by thegolf course, this water still contains fineorganic material.

The effluent is placed in a reservoir untilneeded for irrigation. If the effluent isstored for any length of time, further de-composition of suspended material can beaccomplished by equipping the reservoirwith aeration devices. This can also reduce

problems with odor and algae in the top fewfeet of water.

"The user should realize that effluentwater conditions vary throughout theyear," explains Ken Phillips, president ofYardney Water Management Systems inRiverside, CA. This variation is caused bychanges in sunlight, temperature, and sea-sonal differences in water discharged bysewage treatment plants.

"As we enter the emerging era of dimin-ished water resources, the use of sewageeffluent for irrigation will be of increasinglysignificant concern to all communities andregions, whether they are located in aridareas of the country or not," Phillips con-tinues. The nature of the effluent must betaken into consideration to select theproper type of filtration, especially if theirrigation system includes drip or low-flowzones.

Filtration for suspended organic matterusually takes place downstream of thepump station. Coarse intake screens are notintended to remove fine particles, just largedebris. Fine organic material is not consid-ered a threat to the pumps. The concern isthat suspended organic material may buildup on intake screens and eventually reduceflow. If the flow can't keep the wet pit full,then a low-level detector will shut thepumps down to prevent damage.

Even when potable water is obtainedfrom municipal treatment plants, the pres-sure in the main may fluctuate accordingto the demand from other users. If thepressure and/or flow drop below the de-signed demand of the irrigation systemduring operation, a booster pump may not

perform efficiently, since it is operatingbelow design capacity.

Some variable frequency drive pumpstations can detect drops in pressure orflow upstream. By reacting to signals fromflow sensors or pressure gauges, the mo-tors can protect themselves by rampingdown to compensate for inadequate supply.

As long as the pumps are protected fromcoarse debris and abrasive particles, receivethe correct amount of water through in-takes, and are maintained regularly, theyhave a relatively long life and will providea reliable supply of water to the irrigationsystem. Pump manufacturers recommendservice at intervals based upon their use. Adesert golf course should have its pumpstation checked two or more times a year.A single service call in the fall or spring maybe adequate for courses in wetter regionsof the nation.

The development of the prefabricatedpump station has increased the reliabilityof pump stations and improved repair ser-vice to golf courses. Prior to the '70s, pumpstations were custom-designed from partsof various manufacturers. If there was aproblem, the manufacturer or distributor ofthe malfunctioning part had to be notifiedfor service. Today, manufacturers of prefab-

Automatic self cleaning screen filter by Amiad.

rica ted pump stations assume responsibil-ity for servicing all components.

Superintendents should obtain clear in-structions on preventative maintenancefrom their service technician. Periodic lu-brication, cleaning, and visual inspectionhelp build a better understanding of theequipment and reduce the risk of problems

which could lead to down time.Pumps are designed to leak slightly

around the shaft for cooling purposes. Theamount of leakage is controlled by a pack-ing gland around the shaft. This packingmay need to be tightened or replaced peri-odically by a qualified technician. The golfcourse irrigation specialist should keep aneye on the amount of leaking water andmake sure that drains for this water remainopen.

Electric motors for pumps are aircooled. Anything that restricts air circula-tion around motors can cause them to runhotter and perhaps shorten their life.Screens over air passages should be keptfree and clear of debris at all times.

Bearings on motors should be lubri-cated as needed. The oil in oil-lubricatedbearings should be changed at least twicea year, or more often if the oil turns black.The grease lubricating certain bearingsshould be removed and replaced with freshgrease on a similar schedule.

Finally, the strainer on the control valveshould be cleaned regularly. Ask your ser-vice technician to demonstrate the best wayto clean the strainer.

Basic familiarity with the componentscontinued on page 16

PROTECT YOUR VALVESAND IRRIGATION SYSTEM

FLUSHING OUTLET

\ Amiad Filters are a savings invest-ment. Maintenance costs are dramat-ically cut by these 8" to 14" automatic,electrically or hydraulically operatedfilters that self-clean in "real time:'Amiad technology is unsurpassed forits advanced designs, durable qualityand extended efficiencies of its filters.They protect your valves, operatesolely on mains water pressure, auto-matically flush out particles, and aresuccessfully proven around the world.And they can save you countlessdollars in maintenance. Call Amiadand get the facts now!

~ PRESSURE DIFFERENTIAL

~ ~~.~~~3;;~:~~;~~E~-~o~!O~!~!4~Circle 201 on Postage Free Card November, 1990 15

Pump Stationscontinued from page 15

may be useful if a breakdown occurs andthe service technician can't get to yourcourse the same day. You might be able tosolve some problems over the phone.

Today, computers and computerizedcontrols enable the superintendent or ser-vice technician to access performance datarelated to pump efficiency. This technologypermits the technician to diagnose pumpproblems through a phone modem. Byusing the data to pinpoint problem compo-nents, the technician can identify and ob-tain repair parts before arriv.ing at thecourse.

A properly operating pump station isstill subject to problems occurring down-

, '

stream. Valves and heads are carefully se-lected and programmed to fit specifichydraulic conditions. A leaking valve orclogged nozzle changes these conditions.Filters prevent contamination and assuresystem performance. They also protect thepump station by guarding it against un-planned changes in water flow.

Filters also affect the hydraulic balanceof an irrigation system. If they are added orchanged, adjustments in pump output maybe necessary. The type of filter(s) you needis based upon the impurity in the water, themaximum pressure and volume required bythe system, and the space available.

"No single type offilter will eliminate allimpurities," says Efraim Donitz, presidentof Efco, Inc., North Hollywood, CA. "Thereare three basic types: screen filters, sandseparators, and media filters. A combina-tion of filters may be required to protectirrigation systems on golf courses, espe-cially in cases where effluent is used.

"Before choosing filters, first determine

Downstream sand separator at a sports complex removes sand and grit. Photo courtesy: Lakos.

the type of impurity(ies) in the water andthe quantity of that impurity," adds Donitz."Then you need to determine the flowrequirement of the irrigation system so thatyou'll know what capacity of filter youneed."

Screen filters remove particles that arebigger than the size of the mesh of thescreen. Pressure loss increases as the sizeof the openings in the screen decreases. Byknowing the size of the nozzles in theirrigation system, you can select a meshthat prevents blockage with the leastamount of pressure loss. Drip emitters re-quire the finest mesh screens. When possi-ble, isolate drip zones and filter this waterseparately.

The advent of automatic self-cleaningscreen filters coincided with the need for

Sand media filter by Lakos on Utah golf course.

16 Golf & sports TURF

filtration on golf courses, says Orlans. Heclaims that self-cleaning screen filters todaygreatly reduce the need for media filters ongolf courses. "High-tech screen filters cando the job cheaper than media filters, takeup considerably less space, and cause asmaller pressure loss," he states.

Media filters made a name for them-selves in agriculture as an efficient way toremove organic material from high vol-umes of water. Suspended solids are depos-ited throughout the media (normally sand)in these filters. By reversing the flow ofwater through the filter, the solids arewashed out of the sand. Little maintenanceis required for media filters.

Sand separators remove particles thatare heavier than water. They are importantwhen water comes from wells, rivers, orstreams containing sand or silt. Water frommunicipal sources may also contain partic-ulate matter following construction or re-pair of water lines.

"A large amount of scarce, expensivelabor goes into cleaning sprinklers," Donitzreveals. "Much of this labor can be elimi-nated by using proper filtration on thewater in the first place."

The concern over sprinkler performancehas grown as more golf courses retrofittheir systems with valve-in-head and lower-pressure sprinklers. By seeking greatercontrol over distribution of irrigationwater, superintendents have increased thecomplexity of their systems. As a result,finding the right balance of pressure andflow from the pump station is more difficult.Rising energy prices and use of effluent

water compound the problem.All these changes impact the perfor-

mance of the pump station. Peak efficiencycan be maintained by adjusting the stationto match changes in the irrigation compo-nents, or by controlling the demand of theirrigation system to fit the pump station.Pump station manufacturers have in-creased flexibility from their end by addingsophisticated controls. Recently, manufac-turers of irrigation controllers have re-sponded with equally sophisticated flowmanagement programs.

Both Rain Bird's MAXI IV and Toro'sNetwork aOOO have been enhanced withoptional computer software that adjustsirrigation programs to smooth out the de-mand on pump stations ..Data on the flowrequirements of each station is used toarrange start times. to manage water usethroughout the irrigation schedule. Byeliminating large fluctuations in demand,the pumps can cycle up and down effi-ciently.

Simpler controller functions, such aswater budgeting, can also reduce run timesas well as wear and tear on pump stations.Various moisture sensing devices can belinked with field stations or controllers toaccomplish the same thing. Overwatering

Screen filter with automatic backwash cycle by SyncroFlo, Inc.

wastes electricity as well as water.An irrigation system requires water, en-

ergy, and labor to function. The cost of eachof these is steadily increasing. Events likethe crisis in the Middle East further aggra-

vate our budget problems. To reduce itsexposure to changes in the marketplace,the golf course industry must do all it canto control irrigation costs ...starting at thepump station. ~

For more information contact: Vigoro Industries, Inc. • P.O. Box 512 • Winter Haven, FL 33882(813) 294-2567

Par Ex" and IBDU·are registered trademarks of Vigoro Industries, Inc.

Circle 202 on Postage Free Card November, 1990 17