CEE Oct-Dec 2002

most ine:'\penc;i\e of the PdM technologies discusseu in thi ~ article. Similar to IR thermography. LIT finding s a rc normally immediate and do not requi re trending. The most common use for l T is the detection or air and gas kaks. the most common cause lor :1ir compressor \\car-out and fLtilure. Most kaks arc hard to detect without the usc ol"so::~p bubbles and this can be a time consuming method of inspection. l IT can also be used to detect mechanical problems '' ith be:trings. even on s uch slo \v moving. items, such as k iln trunnions. With the add iti on of sort\\ a rc. rotating-element inspections can be trended similar!) to 'ibration analysi::-.. l:lectrical inspections can reveal arcing nne! other abnormaliti~.:s. froacti\'e 11Wintenw1ce (PAM) is simply 'doing something· about maintenance programme to improve the conditions of assets. o had programmes e:-.ist. just opportunit) f()r impro,·cment and. '' it h t~.: :1m \\' n r k a 11 d a posit i v e pmacti' e attitude to improve the :~pproach ami methods . ma imcnancc organ isnt ion can only get better. l3) making the effor1 to effects analysis (FMEA). Before determining "hal maintenance is required. a knowledge of h O\~ assets can t:1i I and th e probable causcc;, is n~.:ccssat'). This process inc ludes looking at each or the component parts of the asset that arc subject to failure. developing a list of possible causes and determ ining preventive measures to prevent the 1:1ilure. In addition. the mean time between f~ti lures (MTBF) is also considered for establish ing frequency. MTBF is a measure of reliability for repa irable items and is based on history. OEM recommendati ons or engineeri ng analysis. FM E/\ fo rms the ba~ i s fo r develop ing maintenance strategies. laintenance s trategie s establ ish the mnintcnancc mix of reactive, preventi ve and predictive to be appli ed to each asset and strategie s are th e bas is for ck\'elopment of tasks. M::~intenancc tasks contain s peci fics. such as safety precautions, step-b) -step instructions and spec ial tools. In coni un ct ion wi th dcve Iop in g mnintenance s trateg ies. pans strategies are also developed. These lay out the ground\\ ork for stocking the right parts based on annlysis tmpro,·e. and \\ ith the right including such factors as 1:1ilurc nH.:thocbandtecllnolng~.assctscarc likelihood. lead time and storage c~rn be managed and fewer repairs necessitated. Managing ac;se t care not only rcqurres tech nology and maimenance techniques. but abo a ~' stcmatic -~lpproach to implementation. 'I his appro::~ch is cost. Once strategies arc developed. the compu ter ised maintenan ce management system (CMMS) can be updated with ne\\ tasks. CM IS is the hea rt of the regime. The biggc~L problem wi th CMMS is that performi ng root -cause failure analysis (I~CTA) on assets in the future. RC F/\ is o ne or the most valuable tools fo r a reliability engineer. R~CA is a S) Stematic prm:ess used to evaluate the 1:1ilure. identi f) the mechanism . and determine the real root cau:-.c. rile result ofan RCFA is used to motlil)t or adjust the maintenance strat.:gics and . in some instances. design changes may result from an RCI-1\. Maintenance programmes, wheth~r proactive or not. need to be revie\\ecl periodically Cor e flectiveness. Ke y performance ind icato rs (K PI) can provide an economic picture or the effccti\·eness or n maintenance schedule. as \\ell as showing the weak nreas. rile renl evidence or a worki ng programme is the lire cycle costs ora company's assets. If it is found that less is being spent on maintenance. fa il ures arc reduced and equ ipment is lasting longer. the routine is succeeding. C 'ourte.\:t· :World ( 'ellle!lll, .-1 ug 0:!. fp. n3-M Fox: +-1-/(0) 1]5] -/899] E111ail- 111uila lt' orldcelllent.com lf'e/r 11'\i'II'.II'Or/dcellleii/.COI/1 CONVEYING TECHNOLOGY 13ewner 1' !osclllnenfahrik ( /111hll. GemtWII' As a means or Vl.!ltical mecha nical transport. bucket elevators have indispensable links become in the production sequences in many reliability cenicred maintenance it is alm ost always utili sed. and branches or indust ry. (RCivl) and is a process ror determining the right maintenance tl' be performed at rile prope r rntcrvals. Some or the details tor accomplishing this process include s tudies have shown that mos t industries onl) use 15-20% ofthe ir systems capability. Bes ides generating'' ork orders and maintaining time. CMMS is Chain bucket elevators as \\el l as belt bucke t elevators hcl\·c proven their re liability in thousands or applications during ope rat ions under the most diffic ul t and even tkveloping cri ti ca lity levels and a lso a history database. Thi s is ex treme cond ition s. For such conduct ing a f:t ilure modes and impo rtant vvhen il comes to requ irements, s pecial bucket 28 - -.- l \