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Big Savings forSmall Pumps 

Written by Alex Manchenkov, Hugh Sosbee and im Byrom Sr!, "vans Hydro, #nc!, and$alero%Wilmington &efinery

 Pumps & Systems, 'ctober ())*

$alero%Wilmington, a midsi+e refinery -./%kb0d1 located in 2os Angeles, 3alif!, 4asexperiencing problems 4ith oil lubricated vertical in%line pumps AP# type 'H.1! 5hough$alero%Wilmington uses the vertical in%line pumps for multiple applications, several areused as internal transfer pipeline pumps that operate 4ithin the refinery!

Problem

5he Byron ackson pumps, model M$#26, 4ere not e7uipped 4ith any type ofinstrumentation, and since most of the pumps are located in remote areas, daily observationand monitoring 4ere not possible! After running for t4o to four months, the pumps 4ere

losing flo4 and lubrication pressure, causing a rise in bearing temperature and resulting inabrupt catastrophic failure of the thrust bearing! 5his failure also caused damage to themechanical seal, pumping ring and impeller!

#n anuary ())8, $alero%Wilmington sent one of these pumps to "vans Hydro 4ith a re7uestto investigate the failures! 5o determine the root cause of the problem, the engineers started by revie4ing the original sump design! 5he original oil sump design had a magnetic seal atthe bottom see 9igure -, #tem --81! 5he second%generation design had eliminated themagnetic seal and added the riser pipe%the significance of 4hich 4ill be illustrated in thediscovery of the problem!

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5he obvious problem 4as that oil 4as leaking from the bottom of the sump! Afterdisassembly and inspection, the cause of the problem 4as not immediately apparent! 5he oillevel 4as set correctly, there 4as no problem 4ith the pumping ring and no scoring or 4ear4as found on the stationary parts! 5he big 7uestion 4as ho4 the oil 4as leaking from thesump, causing lack of lubrication and the overheating and failure of the bearings!

Approach

5he engineers started looking at the shaft, pumping ring and oil sump housing as a 4holeassembly! 5he :pumping: principle 4as obvious%the pumping ring 9igure (, #tem (1 4assubmerged in oil! 5he outside diameter, 4ith a tight diametrical clearance of !)-(%in to !)-;%in bet4een the upper sump housing 9igure (, #tem .1, 4as producing a perfect pumpingaction and delivering approximately /!*/%o+0min of lubricating oil to the upper thrust bearings!

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#n theory, everything seemed perfect! 5he inside diameter of the pumping ring, riser pipe

and pump shaft 4ere designed to create a labyrinth to prevent oil from escaping! 'nce the pump is started, the pumping ring pumps lubricating oil into the drilled discharge manifold!"nough oil is delivered to lubricate and cool the upper thrust bearing!

#f after only a fe4 months the pump 4as suddenly losing all of the oil from the sump, thensomething had to be causing the oil to travel bet4een the inside diameter of the pumpingring and outside diameter of the riser pipe, then bet4een the pump shaft and the insidediameter of the riser pipe out to ambient!

Since everything 4as making sense in a :static: condition, the engineers decided to consider the effects of the pump

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effect can empty the entire sump 4ithin minutes into ambient!

Solution

"7uipped 4ith this kno4ledge, the engineers started looking at design modifications for the pump! Modifications to prevent oil from being siphoned out of the sump 4ere very simpleand 7uite inexpensive! 5he engineers modified the pump by increasing clearances, thus:breaking: the vacuum bet4een the pumping ring and riser pipe! Spiral grooves 4ere alsoimplemented to introduce gentle air flo4, providing pressure to counterbalance oil backflo4from the pumping ring!

Benefits

5he modifications resulted in a reliable :dry: running pump! 5he first pump 4as modifiedin 9ebruary ())8 and is still in continuous operation 4ithout any sign of oil leaking! 5heremaining four pumps at $alero%Wilmington have been modified and the refinery isobtaining both increased M5B& and cost savings!

'n average, $alero%Wilmington repaired these five vertical in%line pumps every threemonths at >-.,))) each! 5he total repair cost per year 4as >-.,))) x / x -(0.1 ? >(@),)))

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this does not include cost of $espel, seal and bearings1!

#n ())8, engineers repaired0modified these five pumps for >-.,))) each, 4ith the totalrepair cost per year of >-.,))) x / ? >@/,)))! 5hese pumps are still running 4ithout any

signs of problem! 5he first year savings to $alero%Wilmington is >(@),))) % >@/,))) ?>-/,))) and >(@),)))0year every follo4ing year!

#n conclusion, pump rebuilders 4ith highly experienced engineering staffs can providecreative, practical and cost%effective solutions to help pump users achieve pump reliability!

References:

"ric 9reeman, $alero "nergy 3orporation

3armen 'rti+, $alero "nergy 3orporation

 Jim Byrom Sr., president of Evans Hydro, has been in the pump industry for more than 50 years. In the last ! years, he has started four Hydro servi"e "enters in the #nited States.

 Hu$h Sosbee, senior sales en$ineer %ith Evans Hydro, %ors %ith "ustomers in the %estern#nited States on repair, re'rate and up$rades of hi$h ener$y pumps. He has spent the last

!! years %orin$ %ith lar$e (E)s in various sales and mana$ement positions.

%%%.hydroin"."om 

 *le+ )an"henov has - years of e+perien"e in the desi$n, up$rade, re'rate, repair andreliability improvement of pumps and pumpin$ euipment. He has over /5 years of

aftermaret en$ineerin$ e+perien"e. He holds an )S)E de$ree from State )arine

e"hni"al #niversity of St. Petersbur$.

http://www.hydroinc.com/http://www.hydroinc.com/