Basic Principals of Kidney Loop Filtering

 

Basic Principals of Kidney Loop Filtering

 

Index  

Overview

1. - Kidney loop filtration 2. - Filtering Tie -- !ow long s"o#ld yo# sc"ed#le$ %. - &ecoended 'yste Operating Levels (. - 'yste Intervention ). - *"at Intervention is appropriate$ +. - Kidney Loop Filter F ilter ,art pplication pplication 

Oil viscosity relating to oil teperat#re and weig"t/

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Oil oveent 0P/ t"ro#g" t"e filter

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o#nt of oil to e filtered

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Kidney loop vs. f#ll flow filtration

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Filter edia si3e

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Filtering tie

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'yste containation ixing in t"e oil/

4. 5 6e"icle 0#ideline ,overage for Filtration Proced#res

 

Overview Off-line filtering procedures for machine fluid systems are often complicated. A prior knowledge of filtering basics will help ensure the desired outcome. Passing oil through a filter is only one step to managing the total system cleanliness. Succ Su cces essf sful ul resu result lts s are are ob obta tain ined ed when when a holi holist stic ic appr approa oach ch to the the sy syst stem em management is applied. Issues covered in this article relate directly to off-line filtering procedures. The following information should be applied when filtering machine fluid systems.

1. - Kidney loop filtration Is a process where a certain amount of fluid is removed from a system filtered and theninreturned returne d to toreturn the the system. system. This is different different than full flow filtration which is common machine filter applications. In a kidney loop filtration process oil is removed from the system filtered and then returned to the !now dirtier! system for circulation. The contamination level of the whole system is reduced slightly during each pass of the "idney-loop oil. The total contamination level will decrease steadily over time. "idney loop filtration is a slow process# however it is less costly than oil changes and the resulting labor or other types of system cleanup. "idney loop filtration is a process where a certain amount of fluid is removed from a system filtered filtered and then returned to the system. This is different than full flow filtration which is common in machine return filter applications. In a kidney loop filtration process$ 

Oil is removed from the system

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%iltered

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&eturned to the 'now dirtier( system for circulation.

The contamination level of the whole system is reduced slightly during each pass of the kidney-looped oil. The total contamination level will decrease steadily over  time. "idney loop filtration is a slow process. )owever it is less costly than oil changes and the resulting labor or other types of system clean up. The kidney loop filtration process can be implemented during a scheduled P* interval or  af afte terr a ca cata tast stro roph phic ic comp compon onen entt fail failur ure. e. It is in addi additi tion on to yo your ur norm normal al maintenance procedures.

 

2. - Filtering Tie -- !ow long s"o#ld yo# sc"ed#le$ S.O.S sampling is the best method of determining the system contamination level. On site S.O.S information will guide you with this decision. +hen the co cont ntam amin inat atio ion n leve levell has has been been lowe lowere red d to the the reco recomm mmen ende ded d ISO ISO targ target et disco dis cont ntinu inue e th the e filter filtering ing proce process. ss. On site site S.O. S.O.S S inf inform ormati ation on can easil easily y be obtained using a ,aterpillar Portable Particle ,ounter. Information on the use of  a Portable Particle ,ounter during kidney loop filtering is located in the various machine system guidelines.  A time time measurement measurement is another another method of of determining determining the proper proper system filtering filtering duration. This is a very general method but can provide some guidance when a Portab Por table le Parti Particle cle ,oun ,ounter ter is not av avail ailabl able. e. The The follow following ing rules rules are are us used ed to determine the length of time reuired to properly filter a fluid compartment$ . The filtering system must pass each fluid unit of compartment oil through the kidney kid ney loop loop fi filte lterr. To accomp accomplis lish h this this the filte filterr unit unit must must move move / times times the the compartment fluid capacity through the filter. This is due to the mi0ing mechanics and dead compartment areas. 10ample$ If a tank has a capacity of 2 gallons the filter unit must move /2 gallons of oil through the filter one time. 3. To clean and lower the system contamination to a level determined by the filter  media all filtered oil must pass through the filter media 4 times. 10ample$ A system is being filtered through a 2um filter. 5ue to the filter media efficiency all oil needs to pass through the filter media 4 times. This improves the filter media efficiency by filtering a higher percentage of the particles the media was designed to remove. %iltering time can be summari6ed in the following e0ample. System capacity is 72 gallons. / 8 72 gallons 9 32 gallons :to pass all of the oil through the filter one time; 4 8 32 gallons 9 242 gallons :To properly filter the particles out of the oil down to the rated si6e of the filter  media;  A "idney "idney ehicle specific filtration time instructions are located in the various ,aterpillar %iltering ?uidelines.

%. - &ecoended 'yste Operating Levels ,aterpillar *achine operating cleanliness levels do not dictate an allowed level of  system contamination. They are guidelines to help the dealer and customer  manage the machine system health for the life of the product. They are not spec sp ecif ific icat atio ions ns but but are are the the ma ma0i 0imu mum m cont contam amin inat atio ion n 'ope 'opera rati ting ng leve levels ls@@ recommended by ,aterpillar. Operating the machine systems at or below these co cont ntam amin inat atio ion n leve levels ls wi will ll help help achi achiev eve e the the en engi gine neer ered ed life life of the the syst system em components. A system management strategy would be difficult to implement without these guidelines. ased on historic SOS data component life is directly relate rel ated d procedures to pr prop oper er fluid flu id healt he h and and high clea cleanli nline ness ss manag man ageme ement. ,onta ,ontamin minat ation ion ,ontrol such asalth utili6ing efficiency filters ornt. off-board :kidney loop;; filtratio loop filtration n procedur procedures es will reduce reduce or eliminat eliminate e the contami contaminati nation on related related failures so often seen in poorly maintained vehicles. Older machines whose system filtration is not adeuate to achieve the new recommended cleanliness levels lev els wi willll be cove covered red in a separ separate ate docume document nt.. The The engin engineer eered ed life life of any component is attainable by eliminating wear and contamination related failures.

(. - 'yste Intervention +hen should fluid filtration be implementedB +hen should action be taken on a contaminated systemB &efer to +hen to %ilter *achine Systems. %ollowing %ollowin g are several symptoms or signs indicating possible system intervention are reuired$ 

 opening any hydraulic system for repair or service

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 Poor maintenance practices

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