Hallo all,

can someone advice me how to use spare rotating equipement in the oil refining industry/environment? Should one switch to the main one as soon as it is repaired, or not? Is there any specific logic behind it? Any publications, presentations etc could prove helpful.

Thanks,

alexandros

Hello,

Yes, It is helpful to have the rotatable spares to be tracked since we are talking high value equipment or capital items i.e combustion basket, transition pieces or pump and turbines rotor, etc. In Saudi Electricity Company, East Region, we have the CMMS system (Avantis Pro v4.1) to track the equipment by equipment no., serial numbers, and equipment location no. so any changes will be tracked thru Work Order activities of dismantle, refurbished,and installed new or repaired items from the warehouse. So in time, so can easily see the equipment installed history and the current location of the equipment after repaired.

Hope this will help.

Alexandros,
This topic has been discussed in the past, see

http://maintenanceforums.com/eve/forums/a/tpc/f/209103451/m/9601004772
http://www.reliabilityweb.com/art04/operating_philosophy.htm

See also page 169 of my book Effective Maintenance Management, details below for an explanation of the underlying principles.

Alex, There are differant answers to this question. But basic is we may like to run "A" critical equipment every week or fortnight, "B" critical equipment every month, "C" critical every year or so. Some of the logics are:
* Each start up / trial reduces life of the mechanical seals.
* If ring lubrcated bearings are idle for long time say more than 3 months, we loose oil film and some times corrosion issue. If oil mist OR pressurised lube is used than this may not be the case.
* If motors are kept idle for long say more than 4 momths (without space heaters) than magger value ma come down.....
These are some of the thoughts only worth 2 cents.

I have some that are four units coming on per demand but there's a lead and an order which is programmable. You will want all to run different length of times but all to go through rotation.

Example: 3 pumps w/2 in operation - one back-up. Rotation should work out (math logistics) to be that one pump has 50% one 30% and one 20% time on it. This way no two should fail at the same time and false brinnelling can be avoided. Many control stations anymore are fully computer controlled and easy programmable. this will give you 100% availability and reliability.