Tee with blind flange or Bend at Pump Header

[selftaught]

I wonder whether to use a tee with blind flange or a bend (for last pump) at the end of pump header. Is there anybody to tell me cons and pros for each one?

 

[BigInch]

If you're thinking of using a bend on the end of a header, you're header is pretty small diameter. I mean you have a header the same size as your pump discharge. Or do you have a telescoping header (more than one size)?

You generally need to have a header larger than your pump discharge diameter when you have 1+n pumps operating simultaneously, each at 1/n * BEP flow, which would require making your downstream piping a larger diameter than what is needed for your pump discharge size alone (assuming you're trying to keep the same velocity at all points).

That aside, you must also look at the potential for adding more pumps in future and the difficulty that would be involved with cutting off the bend and extending the header. Evaluate that against the probability of adding a pump some day.

**********************
"Pumping systems account for nearly 20% of the world’s energy used by electric motors and 25% to 50% of the total electrical energy usage in certain industrial facilities." - DOE statistic (Note: Make that 99.99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[pennpiper]

selftaught.
Your screen name says a lot and you have not given us enough information to offer any real help.
You also use the term "Bend" in your question. I suspect you really mean "elbow". There is a difference between the two terms when used in proper piping.

What is the suction source?
Elevation wise where is the source located relative to the pumps?
What is the commodity in this system?
What is the operating temperature and pressure?
What is the size of the suction pipe at the source?
How long is the suction line from the source to the pumps?
What is the pump suction nozzle size (all pumps)?
What is the pump discharge nozzle size (all pumps)?
What is the discharge line size after the pump block valves?
How long is the discharge line from the pumps to the termination?

 

[Artisi]

is it inlet header or discharge header?

 

[selftaught]

To pennpiper :
Yes. I mean "elbow" by "bend". To clarify let me explain. I've to reach a line to suction of three pumps and also collect discharge of them to another line (line=header) according to a P&ID. i'm at decision of whether to use elbow or a tee with blind flange a the end of each line for the third pump.

To BigInch :
If i got you, your point is for using tee with flange, i there any consequences in this regard other than cost?

To Artisi :
Does it matter?

 

[pennpiper]

I seldom disagree with "BigInch" he is a well trained, vastly experienced and wise member of the piping profession. However it is not normal to use a blind flanged TEE where an elbow will perform the task.
The TEE method will double the cost of making a simple corner in most services including water or oil.
Selftaught, you have not answered my questions.

 

[Artisi]

Yes, especially if it is on the inlet and pump is bolted directly onto the "T".

 

[selftaught]

To pennpiper :
What is the suction source? Ans: if i got your mean by "source" it is "header".
Elevation wise where is the source located relative to the pumps? Ans: See the attached files
What is the commodity in this system? Ans: don't understand
What is the operating temperature and pressure? Ans: don't know
What is the size of the suction pipe at the source? Ans: See the attached files
How long is the suction line from the source to the pumps? Ans: about 2 meters
What is the pump suction nozzle size (all pumps)? Ans: See the attached file
What is the pump discharge nozzle size (all pumps)? Ans: See the attached file
What is the discharge line size after the pump block valves? Ans: See the attached file
How long is the discharge line from the pumps to the termination Ans: what do you mean by "termination"?

 

[selftaught]

Sorry i have also a sample file to show the header with blind flanges...

 

[Artisi]

Can't see any real problems with the setup shown on your drawings - up to you which way you handle it.

 

[BigInch]

attached diagram

My preference is always #1 because you have freedom to expand in either direction.

I have used #2 on occasion (without the left 2 bends) due to battery limit constraints, pipeways etc. Expansion is blocked in your configuration.

I've never seen #3. Looks pretty though. If you replace T with L everywhere you could, it would look like that. Do you really want to do that?

Pennpiper, Thanks. I think the same about you too. Yes I believe it is the very first time you have disagreed with me. Did you really??? No problem, but if I didn't know any better, I'd think you're suggesting arrangement #4. just kidding, just kidding.







**********************
"Pumping systems account for nearly 20% of the world’s energy used by electric motors and 25% to 50% of the total electrical energy usage in certain industrial facilities." - DOE statistic (Note: Make that 99.99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[pennpiper]

What is the suction source? Ans: if i got your mean by "source" it is "header".
No! The source is a Tank on grade, or a cooling tower basin, or a Vessel (elevated on supports).
Now what is the source?

Elevation wise where is the source located relative to the pumps? Ans: See the attached files
No! The source is either on grade at the same level as the pumps or it is elevated.
Which is it?

What is the commodity in this system? Ans: don't understand
A Commodity in a line means what is in the line, Water? Oil? Ammonia? What is in the line?

New question: Why are these lines Heat Traced? Do you know what Heat Tracing is?

What is the operating temperature and pressure? Ans: don't know.
Why don't you know. You should not be doing any piping on 18" piping (subject to Heat Tracing) with out knowing what the Operating conditions (pressure and temperature) will be.
Have you considered the effect of thermal expansion on your piping system?

What is the size of the suction pipe at the source? Ans: See the attached files
The attached file of the P&ID shows three (3) pumps. The layout sketch shows four (4) pumps. Why is this?
Also the layout sketch appears to show the "Y" strainers on the suctions installed backwards. You should recheck that.

How long is the suction line from the source to the pumps? Ans: about 2 meters
I don't think so. How far is it from the Tank to the pumps? 50meters? 100 meters? How far?

What is the pump suction nozzle size (all pumps)? Ans: See the attached file
What is the pump discharge nozzle size (all pumps)? Ans: See the attached file
Wrong! The P&ID does not indicate the Suction nozzle or Discharge nozzle size of the pump. The layout is not clear enough to tell if a reducer has been installed. Please look at the Pump drawing and tell us what size the pump suction and Discharge nozzles are.

What is the discharge line size after the pump block valves? Ans: See the attached file
(?) at the pump nozzle, then 10" for the discharge valving on each of the three pumps and then manifolded into a 12" discharge header.
Note: The P&ID shows one pump with a 10" discharge block valve and the other two show 12" discharge block valves. Why is this?

How long is the discharge line from the pumps to the termination Ans: what do you mean by "termination"?
The termination point is the next piece of equipment where the commodity is going.

 

[Artisi]

pennpiper.

Maybe, just maybe what you are asking is too difficult for the OP. It is possible that he/she is a welder / pipe installer and doesn't know one end of a pump from another and the opening question was a simple plea for clarification and who by now could be so confused they don't know which way is up %-)

 

[pennpiper]

Artisi,
Good point. I had not thought of it that way.
Thanks

 

[rmw]

Based on what I saw, I would not recommend against the capped TEE in this application. I have other questions but they aren't part of the OP so I won't go there.

rmw

 

[selftaught]

pennpiper,
I really didn't wanna get you into trouble by my question. Thank you for your time. Now i understand some of your terms. it seems we are going to reach to an optimum design for entire process!
actually, that perpective view is a sample to explain my point about tee(with blind) at the pump header and it not related to the (partially shown) P&Id.
with regard to pumps, they are in HOLD condition (not completely selected).
The tanks which are discharged by these pumps to the jetty are approximately at the same level of the pumps skid.
Commodities are different, fuel oil, naphtha, kerosine.
Some tanks are far and some are near. from 100 m to 20 m distances to the pumps location.

 

[BigInch]

3 products makes a difference! If you're running 3 products in the 1 pipeline, do whatever you need to do to eliminate dead legs, or keep them as short as possible. With 3 in 1, a T into/from a header is probably not going to be the most advantageous configuration, but you could still use it, if the header end caps are kept very close to the pump branches. But even that doesn't matter, if the end pumps are ever on standby duty. With both header configurations, each will have a virtual dead leg, if any end pump is not running. You might need a small line(s) from the header to an interface tank, so you can flush the previous product completely from the header before flowing the new product into the outlet pipeline. That depends on how much product might be trapped in a header or other dead leg and what the volumes of the tanks are. If blending of trapped volumes into the tank volume will cause contamination limits to be exceeded, you will need to flush significant dead leg volumes to an interface tank first before filling downstream pipe segments with the new product.

**********************
"Pumping systems account for nearly 20% of the world’s energy used by electric motors and 25% to 50% of the total electrical energy usage in certain industrial facilities." - DOE statistic (Note: Make that 99.99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[selftaught]

BigInch,
those products will not mixed. Three parallel pumps will be used for every product. Wasn't my question simpler than this? Let's go to the heart of the matter.
Pros and Cons for "Tee with Blind " or "Elbow" at the header.

 

[pennpiper]

Selftaught,
You sent us a piping layout sketch, then you said that the sketch is not of your project.

You sent us a portion of a P&ID (suggesting that it was for your project. This P&ID shows that the three pumps use a common suction header, a common discharge header and a common Flow Transmitter (FIT). Now you tell us that the products will not be mixed.
You need to understand that the use of the pump/piping set-up shown on the P&ID the products will be will be cross contaminated.

 

[BigInch]

Its been fun. Bye now.

**********************
"Pumping systems account for nearly 20% of the world’s energy used by electric motors and 25% to 50% of the total electrical energy usage in certain industrial facilities." - DOE statistic (Note: Make that 99.99% for pipeline companies)

http://virtualpipeline.spaces.live.com/