whats ur experience in sealing 1200 cP viscosity liquid?

[reallyme00]

whats your experience in sealing 1200cP viscosity liquid at ambient temp. ? would upstream pumping seal be helpful in this application? or u have any good reliability record with any other crane seal for this application? if uptream pumping seal being used for this application, i'm very much convinced when the seal rotates...but, how about the start up after a period of time,pump being in stand by condition...? will there be any issues such as seal faces break due to seal faces stick together?

Feel free to ask me any other details required regarding this issue..

Appreciate and thanks in advance for your valuable replies....

Best regards,

Really.

 

[flexibox]

Very good question. In operation the Upstream seal is fine I would only be concerned when shuting down as the hydrodynamic lift reduces can product eventually find its way across the face and possibly the grooves affecting dynamic lift performance on start up? what is the Seal Chamber pressure? My choice for this is a dual pressurized seal but I also understand the Upstream seal is a good option at less costs.
What is the product? It sounds like contamination of buffer fluid is not an issue for the duty, have you considered product contamination?

 

[longeron]

One way to reduce the problem during start-up is to use a liner of sorts that acts like a lip seal on the shaft sleeve. Imagine a PTFE gland gasket that extends into the seal chamber that then tapers down and "rides" on the shaft sleeve just a bit further into the seal chamber than the seal faces. The volume inside the liner can eventually fill up with your buffer fluid keeping the process fluid away from the faces at start-up. Have a chat with your salesperson about this.

 

[reallyme00]

First of all, Many thanks to Flexibox and Longeron...

The service product is Phenates...The chamber pressure is around 1bar absolute.
Initially we thought contamination is ok @ minimum level while using 150 N lub oil as barrier fluid.
Later we realized that the inflow of barrier fluid due to upstream pumping seal would be 1lit/min , which enormous as contaminant and running cost-wise as well.

Now, we have to drop the idea of putting USP seal for this application.

Present seal is single bellow seal and it fails very frequently due to various reasons such as bellow fracture, seal faces chipping...(The pump cavitates most of the time during each transferring).

Not sure if a double bellow seal would work...we will have to try it.

We will discuss about Longeron's idea of putting a gasket in the seal chamber as lip seal with the sales person.

Thanks again.Feel free to let me know if u have any more ideas to explore.