Adjustable Support in Pump

[marchieV]

Hello.

I need your opinion and experience in the design of pipeline connected to a pump. Is it necessarily needed to consider the first support Suction/Discharge to be an Adjustable Dummy?
I have problem with my current project because the client wants to use adjustable dummy because that's what's written in their specification but the problem is, that first support is already existing or operating in the site for many decades and it out of our scope. They're insisting to replace the simply supported pipe into an adjustable support. Is it necessy to install adjustable support or it depends on the site condition?

Please, I need your opinion and expertise. Thank you.

Regards,

March

 

[LittleInch]

Can you describe what you mean by an adjustable dummy?

Connections to pumps are quite difficult as the pump is often very sensitive to forces being applied to it from the piping and needs to be matched very carefully.

Dependant on the piping flexibility an adjustable support may be the most convenient way to do this, but there is no common requirement AFAIK.

Smaller pumps tend to be less sensitive.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[marchieV]

Our problem is that this support is existing or already operating in the site without that adjustable support. But the client insisting to replace it just because it is written in the specification. I've done analyzing pump before in other project but I did not notice that adjustable support is a must in pump. Is it really necessary? Why is it so hard to justify on what is in the site (operating for decades) versus the specification they just recently made?

 

[LittleInch]

It's all about the practicality of getting the pipe and it's flange to meet the pump flange without any real forces being applied to the pump.

pumps can be quite sensitive to flange loadings in respect of alignment of the pump and motor and stresses within the pump itself.

That drawing though looks like an adjustable support?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[marchieV]

I already consider that alignment during the analysis, that's why I recommended some temporary support during installation. I know the purpose of the implementation of adjustable support. What is not clear is that the original line is already there in the site and it is functioning well. We just had some minor modification in the line then now they suddenly want an adjustable suppport.

 

[LittleInch]

OK, Sorry I might have missed the issue.

Are you actually changing anything with this support (new pump?) or is the client trying to suddenly retrofit adjustable supports in place of the current fixed support?

If the latter and it's out of your scope just tell him that. Changing existing set-up just because someone has changed it for the new equipment is not normal, mainly due to cost and disruption unless it is required for safety or operational reasons.

If the pump is fine, runs well, fully aligned, then there is no justification.

But sometimes the client can be an a$$.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[curtis2004]

Hi,

It seems this is contractual issue - not a technical.

Thanks,
Curtis

 

[mk3223]

IMO, the adjustable support seems a requirement because it's specified in the Client Spec.
It could be true that there is no problem for the existing fixed support on the pump piping which you are working on due to the "correct" installation. But, the "adjustable" support can provide some construction flexibility for the pump piping with a better alignment.

 

[1503-44]

This is usually not required except in cases of very high operating temperatures.

“What I told you was true ... from a certain point of view.” - Obi-Wan Kenobi, "Return of the Jedi"

 

[marchieV]

Thank you guys for all your opinion. Anyway, whatever will happen, clients will always have the rights and needs to be followed.

 

[1503-44]

If there was a real need for that, you would probably be looking at a spring can, but "He with the gold maketh the rules" is the way it usually ends.

“What I told you was true ... from a certain point of view.” - Obi-Wan Kenobi, "Return of the Jedi"