Editing Pump (section)

==Pump repairs==
[[File:Derelict windpump with water tank in the foreground next to the Boorowa railway in Galong NSW Australia.JPG|thumb|Derelict windmill connected to water pump with [[water storage]] tank in the foreground]]
Examining pump repair records and [[mean time between failures]] (MTBF) is of great importance to responsible and conscientious pump users. In view of that fact, the preface to the 2006 Pump User's Handbook alludes to "pump failure" statistics. For the sake of convenience, these failure statistics often are translated into MTBF (in this case, installed life before failure).<ref name="mt-online.com">[http://www.maintenancetechnology.com/2008/10/pump-statistics-should-shape-strategies/ Pump Statistics Should Shape Strategies] {{Webarchive|url=https://web.archive.org/web/20160304064822/http://www.maintenancetechnology.com/2008/10/pump-statistics-should-shape-strategies/ |date=2016-03-04 }}. Mt-online.com 1 October 2008. Retrieved 24 September 2014.</ref>

In early 2005, Gordon Buck, [[John Crane Group|John Crane Inc.]]'s chief engineer for field operations in Baton Rouge, Louisiana, examined the repair records for a number of refinery and chemical plants to obtain meaningful reliability data for centrifugal pumps. A total of 15 operating plants having nearly 15,000 pumps were included in the survey. The smallest of these plants had about 100 pumps; several plants had over 2000. All facilities were located in the United States. In addition, considered as "new", others as "renewed" and still others as "established". Many of these plants—but not all—had an alliance arrangement with John Crane. In some cases, the alliance contract included having a John Crane Inc. technician or engineer on-site to coordinate various aspects of the program.

Not all plants are refineries, however, and different results occur elsewhere. In chemical plants, pumps have historically been "throw-away" items as chemical attack limits life. Things have improved in recent years, but the somewhat restricted space available in "old" DIN and ASME-standardized stuffing boxes places limits on the type of seal that fits. Unless the pump user upgrades the seal chamber, the pump only accommodates more compact and simple versions. Without this upgrading, lifetimes in chemical installations are generally around 50 to 60 percent of the refinery values.

Unscheduled maintenance is often one of the most significant costs of ownership, and failures of mechanical seals and bearings are among the major causes. Keep in mind the potential value of selecting pumps that cost more initially, but last much longer between repairs. The MTBF of a better pump may be one to four years longer than that of its non-upgraded counterpart. Consider that published average values of avoided pump failures range from US$2600 to US$12,000. This does not include lost [[opportunity cost]]s. One pump fire occurs per 1000 failures. Having fewer pump failures means having fewer destructive pump fires.

As has been noted, a typical pump failure, based on actual year 2002 reports, costs US$5,000 on average. This includes costs for material, parts, labor and overhead. Extending a pump's MTBF from 12 to 18 months would save US$1,667 per year — which might be greater than the cost to upgrade the centrifugal pump's reliability.<ref name="mt-online.com" /><ref name=SlurryPump>[http://www.engineeringnews.co.za/article/submersible-slurry-pumps-in-high-demand-2006-10-06 Submersible slurry pumps in high demand]. Engineeringnews.co.za. Retrieved on 2011-05-25.</ref><ref>{{cite news| last = Wasser, Goodenberger | first = Jim and Bob | title = Extended Life, Zero Emissions Seal for Process Pumps | work= John Crane Technical Report | publisher =  Routledge | id = TRP 28017 |  date=November 1993}}</ref>