mechanical seal substitution 1

[Elarbi]

Has anybody experienced replacing mechanical seals from one brand to another? How easy was it?
Any useful address on this? Articles? Real life experiences especially in oil & gas industry?

Thanks.

 

[stopsunset]

I work in an oil refiney and lasy year we adopted a fix fee program for our mechanical seals.The vendor that we selected previously had maybe 5% percent of the seal population.Seal conversion is a simple task for the vendor, especially if they have detailed drawings.If no drawings are available sometimes measurements are needed(nearest obstruction,box bore/depth, etc..).We have successfully implemented over a hundred conversions with absolutely no problems.

 

[Elarbi]

Hello Stopsunset,

Thank you for your reply.
Is your selected vendor replacing progressively all the refinery mechanical seals by his, or is he just maintaining the ones from other manufacturers (replacing parts)?
What do you mean by the fix fee program?

Regards.

 

[stopsunset]

Depends....If the failed seal has no history of reliability problems the vendor is sending that seal to the manufacturer for repairs and shipping back to us(this is rare).If the seal is flagged as a "bad actor" or something is identified with the design that needs improvement they are converting it to their seal. Fix fee is a type of alliance program which establishing a more formal relationship with the a particular vendor-condensed version...ask your vendor for more details on this.Hope this helps

 

[Milkboy]

Many seal vendors will have an equivalents list where they know which seals can be swapped out for their own quite easily.
i.e. Burgmann MG901 = John Crane Type 1 = Sealol 43CE etc.

Many seal types will be certain fits/changes if the pump type is know as a certain standard, DIN say.
i.e. Burgmann MG912 for DIN = John Crane 502 for DIN

When it comes to the bad actors which should be picked up and actioned by you vendor, a simple change of brand is not usually a 'magic wand' which will remedy the bad actor.

In my experience, something else may have to change and you vendor will show his worth when they analyse the problem berth and solve the problem.
Adding a new piping plan, increase cooling, for example

Any of the major seal companies products should do the job if selected, applied and operated correctly.

So, in my opinion, the change brands is easy.
Eliminating the Bad Actors via a Reliability Program
is when your 'deal' with the vendor should prove its worth
and you see your plant MTBF go up.

It shouldnt just be about one vendor undercutting another.

5% saving on seal purchases cost and thats it so one guy can get the business??

A good reliability program with a dedicated vendor in collaboration with the plant could save +30% on seal spend.

HTH

-
Milkboy

 

[daveboy]

Some words of concern

I have had a lot of experience in the past few years of purchasing departments selecting equivelant seals from alternative supplier as they are cheaper than the specified seals without paying attention to all the limitations or having any engineering input and relying soley on the seal manufacturers statments on equivelants.

Because the seal manufacturer says is is equivelant to their competitors doesn't always mean it is.

 

[longeron]

As has been mentioned before most of the major seal mfgs will have drawings for something close to what is already used in your application.

A better path is to work with your new seal vendor to evaluate the service. Make sure that both of you know all of the service information, verify the seal chamber dimensions, and then review what you have used. A thorough look at the old seal is a good idea too. Evaluate it's condition, work with your vendor to perform a quick failure analysis and compare what you see with this seal to the pump's history to determine if the seal already installed is a good fit for the service.

Only after taking a good look at the seal and the service can a successful change be made.

Milkboy is right- the service behind the seal is just as important as the seal itself.