Pump Suction Piping
Pump Suction Piping
(OP)
Dear All,
I need to install a pump having a suction size of 3". The suction is taken from a tank and because of lack of space, it is not possible to install a 3" line. So we are thinking to install 2 numbers of 2" pipe and connect them to a 3" tee and then connect to the pump. Is it feasible to do such an arrangement? If yes what should be the minimum straght length of pipe before the suction nozzle?
Thanks in advance
I need to install a pump having a suction size of 3". The suction is taken from a tank and because of lack of space, it is not possible to install a 3" line. So we are thinking to install 2 numbers of 2" pipe and connect them to a 3" tee and then connect to the pump. Is it feasible to do such an arrangement? If yes what should be the minimum straght length of pipe before the suction nozzle?
Thanks in advance





RE: Pump Suction Piping
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Pump Suction Piping
But maybe I'm being too pedantic... go for 10D straight lenght as Artisi says. If it's more complex, draw a quick sketch with distances, flow rate, product etc.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Pump Suction Piping
That hardly seems possible. Two 2" (2.375" OD) even touching each other is still a greater distance than the OD of a 3" (3.5") Anyway....
Do you really need 10 diameters on such a small pump.
My feeling is that 5D would work OK.
Independent events are seldomly independent.
RE: Pump Suction Piping
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Pump Suction Piping
http://www.eng-tips.com/threadminder.cfm?pid=1529
Use translation assistance for Engineers forum
Note the rules include No Student posting
RE: Pump Suction Piping
If it's a very serious pump at all the manufacturer wants the inlet flow to be treated gently and with respect and probably issues warnings like this -
"A short elbow should never to bolted directly to the pumps suction nozzle. The disturbance in the flow caused by the sharp bend so near the pump inlet may result in noisy operation, loss in efficiency, and capacity, and heavy end thrust."
http://www.pattersonpumps.com/pdf/end%20suction.pd...
http://www.cranepumps.com/downloadables/CATALOGS_O...
rules 3 and 4 here -
http://www.pumps-filters.com/images/Rules_to_Follo...
I'd be thinking about slow tapers, vortex breakers and turning vanes as much as maintaining area.
RE: Pump Suction Piping
To get more useful help, please provide more useful information and include a sketch of the configuration.
Valuable advice from a professor many years ago: First, design for graceful failure. Everything we build will eventually fail, so we must strive to avoid injuries or secondary damage when that failure occurs. Only then can practicality and economics be properly considered.
RE: Pump Suction Piping
What kind of pump (Positive Displacement,Centrifugal, Progressive Cavity, etc)?
What is the Commodity (Beer, Oil, Water, etc)?
What are the Operating conditions (pressure/temperature)?
What is the Design Code for this installation (ASME B31.1, B31.3, etc)?
You wrote:
"I need to install a pump having a suction size of 3"."
Normally the Tank Nozzle and the suction line is minimum one size larger than the pump nozzle. This means the Tank nozzle and the suction line size should be 4"NPS.
What is the size of the Nozzle on the Tank?
"The suction is taken from a tank and because of lack of space, it is not possible to install a 3" line."
You wrote this but you did not give any reason. This is not logical! Have you considered reversing the pump on the foundation? Have you considered moving the Pump to a new location?
"So we are thinking to install 2 numbers of 2" pipe and connect them to a 3" tee and then connect to the pump."
As already stated this is not logical. It also sounds like it would be very bad design.
"Is it feasible to do such an arrangement?"
Oh! it is feasible to do lots of things with pipe and pipe fittings but that does not mean it is good design.
"If yes what should be the minimum straight length of pipe before the suction nozzle?"
If you ask ten different pipers this question you will get ten different answers.
Can you provide a sketch?
prognosis: Lead or Lag
RE: Pump Suction Piping
RE: Pump Suction Piping
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Pump Suction Piping
It has been more than a month since you posted your question and more than two weeks since you received the last response.
What did you finally do?
prognosis: Lead or Lag