API Flush Plan for HSRN and RCO 2

[hhmh2004]

In one of the jobs I have to specify a pump which will operate on 02 services. One service is HSRN (Heavy Straight Run Naphtha) and the second service is RCO (Reduced Crude Oil).

The Max Temperature for HSRN Case is 179 deg F and for RCO Case it is 588 deg F.

For HSRN case API Flush Plan 11 is acceptable. My Question is can this same flush plan be used for RCO service as well?

My other question is can I specify API Plan 23 for this job as well?

Remember the same pump has to operate on both services.

Thanks

 

[JJPellin]

I have never heard of someone trying to design a single pump for such diverse services. If these were two separate pumps, I would suggest a Plan 11 for the naphtha and a Plan 31 (HVGO) for the reduced crude. I don't see any reason to change the recommendation just because they are not separate pumps. I would pipe a plan 11 to use when running naphtha and a Plan 31 to use when running reduced crude. Plan 23 would be problematic in our plant in winter when the reduced crude would set up in the lines to and from the cooler. As a result, I have never seen Plan 23 used in a stream this heavy. Even in a location without cold winters, I would not recommend it.

Johnny Pellin

 

[hhmh2004]

Thanks for your reply it really helped a lot.

Actually the specified pump is the part of a closed drain system for a refinery and takes suction from a vessel which receives drains from different equipment of the refinery through closed drain piping. So the pumping service is diversified and it is first time for me as well to specify a single pump for two services.

Plan 31 is a variation of Plan 11 with the inclusion of a separator. One more question...Can I use a metallic below type seal instead of pusher type and remove the throat bushing and stick to the plan 11 for both services?

 

[hhmh2004]

I forgot to add...

What about temperature effect on Seal it self? As in case of Plan 11 OR 31 the RCO would be going to the seal at a max temperature of 588 deg F.

Thanks and Regards,

Haroon

 

[JJPellin]

I am very sorry. I need to do a better job of memorizing API Plan numbers. I intended to suggest Plan 32 for the reduced crude service. We would normally have a unit-wide flush system using cool, filtered HVGO for the heavy oil services in the crude units. This would be preferred.

In any case, I would design the seal for high temperatures using bellows seals and high temperature gaskets. I would probably add a steam quench (Plan 62) for the atmosphere side of the seal to reducing coking.

In your original post, you described this as a pump with two services. This suggests that it would see either one or the other. In your second post, it makes it sound as if this is a slop pump that could see any mixture of streams across the full range from heavy naphtha to reduced crude. That makes a difference. If the pump has to be able to pump whatever stream is dumped to slop, then my suggestions would change.

I would use a metal bellows seals with high temperature gaskets and hard faces. I would pipe it up with Plan 32 outside flush if available. If clean flush was not available, I would use a Plan 11/62.

I should have asked more questions to understand your service before I commented.

Johnny Pellin

 

[hhmh2004]

Thanyou so much Mr. Johnny Pellin....your explanation helped a lot...

 

[pumpkind]

It is in my opinion an unfortunate decision - this pump will experience temperature shocks at every change of duty - apart from the case itself and all the wet components - how will the bearing and coupling alignment cope with this ? The seal faces ? How will the seal plan switch over be accomplished ?
We do not know all the facts - but I have never heard of a pump being used for such a vastly difference of temperature without progressing being taken to the right temperature - process which takes a long time