Mechanical Seal Barrier Fluid???

[andrewsjo]

We are designing equipment using FLowserve mechanical seals. We originally intended to use Royal Purple GT78 (

http://www.royalpurple.com/prodsi/bfgt.html)

as the barrier fluid (1.0 gpm flush @ 300F inlet temp).

Now, the end-user has asked us to address switching from GT78 to Methyl Oleate or Gylcerol. Flowserve has been very general in their response on what they are willing to "sign-off" on...and as we all know, generalities do not fly with refineries and engineers!

Can someone comment on these barrier fluid choices and perhaps offer some wisdom??

Methyl Oleate -> Flash Point=350F, Boiling Point=650F, 0.6cP @300F

Glycerol -> Flash Point=320F, Boiling Point=550F, 4.0cP @300F

Royal Purple GT78 -> Flash Point=482F, Boiling Point=760F, 4.4cP @300F

John

 

[bingopin]

Do you mean flush or barrier fluid? I am not clear on why you call out a flow rate (1 gpm)for a barrier fluid?

 

[andrewsjo]

It is technically a flushing system. I mistakenly used the terminology of barrier fluid, since it is a bouble seal, thus creating a pressure barrier (net 0 leakage of process fluid into atmosphere).

Any insight on "flush" oils?

John

 

[longeron]

1gpm of this fluid injected into the seal chamber? You must have a really tight throat bushing.

They want to inject a fatty acid into thier process? I'm not sure why the pump/seal company would object. This is a call that the customer has to make. As long as the hardware and soft goods are compatable with the fluid they should be fine with it. (It appears that Fluoroelastomers should be acceptable, but don't take my word, check the Parker book or another O-ring compatability chart)

Pray tell, what is the process fluid?

Check out the following link for more on Methyl Oleate:

http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=136634&pf=1

 

[jjfa]

I agree with what longeron says, 1gpm injected into the seal chamber?.

I would like to know what is the product you are sealing, and the API Plan been used, I guess It could be API Plan 52 or 53 in which the product won´t go to the atm.

 

[quadtracker]

In a API plan 52 barrier fluid tandem seal arrangement Royal Purple fluid has exceeded most operating conditions where others have failed. My experience and from others using it, it seems to be the best out there for extreme temperatures.