7 replies to this topic

[anh.phungthai@boydensvn]

Hello everyone!

I have a question about piping design.

Which better option is designed for the pump pipeline, between options to install expansion direct to Pump or expansion after reducer (Reducer install direct to pump). 

Have a nice day!

Thanks a lot!

[breizh]

Hi,

https://blog.craneen...gal-pump-piping

Will it help?

Breizh

[anh.phungthai@boydensvn]

Hi Breizh,

Thanks for your shared.

However, the content which them mentioned on the web does not relate to expansion accessories.

We also know that expansion (For Pump) is used to for:

• Turbulent Effects: Suction piping is typically aligned directly with the pump impeller to prevent turbulent effects. However, this arrangement can create challenges when it comes to accommodating thermal expansion or vibration.
• Erection and Maintenance: Expansion joints serve as a solution by allowing the erection and maintenance of the suction valve. They provide the necessary flexibility to absorb thermal expansion and contraction without imposing excessive loads on the pump flanges.
• Noise Reduction: In building services, expansion joints also help prevent noise transmission via the piping system.
• Flexibility: Modern construction practices may not always allow for perfectly aligned and rigid piping. Expansion joints offer flexibility, especially when skilled craftsmanship is scarce.

In fact, you will see sometimes they install expansion direct to the pump (nozzle inlet & outlet), Sometime after reducer. (Please see illustration link).

 

Option 1: https://www.piping-d...nstallation.jpg

Option 2: https://www.shutters...roof-1790897507

 

so, which is the recommend option? and explain why?

[Pilesar]

It is best to have a straight run of pipe entering a centrifugal pump. You want the flow pattern at the inlet to be uniform.

[shvet1]

There are a lot of practices of pump piping, only I have encounered at least 4 totally different ones. I am sure forummembers can share much more.

 

For example see an extract from a paper I have prepared far ago

 

 

 

Note that most process industry majors use API or ANSI.

 

so, which is the recommend option? 

 

Follow the local code/practice.

 

and explain why?

 

Because such the local tradition is, no one will blame you if you follow the existing code/practice. 

 

Different people at different times independently provided industry studies, some of them also experiments, drew conclusions, and published results. If their results become different that means that goals, criteria and conditions of the work they have done were different. No magic.

 

PS

Keep asking questions. To yourself and others. This is normal. There is no pre-determined things in this universe. I have seen cases where one stupid question made wasted years of efforts of hundreds of people and amount of money&resources compatible with a year budget of a small country.

 

When the newcomers stop doing this, humankind will perish.

Edited by shvet1, 01 March 2024 - 12:51 AM.

[anh.phungthai@boydensvn]

Hi Pilesar and Shvet 1,

Thanks for your advice.

I think, i  have not description clearer in my question.

I mean, in case of suction pump line, which sort order we will recommend for design.

 

1. Eccentric reducer->Expansion -> Inlet nozzle of Pump

2. Expansion-> Eccentric reducer-> Inlet nozzle of Pump

 

as you know almost expansion have wavy structure (inner also). Therefore I worry if we installation expansion direct to inlet nozzle of pump, it will be creating air bubbles and causing cavitation of Pump impeller. but I'm not sure. another different is pressure loss.

So if we don't care about the cost, pressure loss. we only consider the technical aspect. Which the sort order we want to like to recommend.

[shvet1]

I mean, in case of suction pump line, which sort order we will recommend for design.

 

Depends on applicable local code/practice. You should find out or adopt some by yourself.

 

Note that most majors use relevant API or ANSI code. For details see above.

Edited by shvet1, 01 March 2024 - 06:06 AM.

[breizh]

Hi,

Upload a sketch.

Breizh