Pump Foundations - Concrete Free

[DiegoCB]

Hi all!

I'm looking for information about alternatives to concrete in pump foundations.

Please, I would be glad if someone with experience in those kinds of installations could share some information with me.

The pump which we are working on is a 500HP HPS pump for 10000BWPD.

Best regards!

 

[HTURKAK]

If concrete is free , you may go with a sturdy design.. The wt of foundation should be in the range of 3 to 5 times of wt of the pump. But these figures for rule of thump . You are expected to perform dynamic analysis.

I will suggest you to look ( ACI 351.3R-04 Foundation for Dynamic Equipment ,API RECOMMENDED PRACTICE 686 Machinery Installation , Design of Structures Foundations for Vibrating Machines-Gulf Publishing , Grouting Handbook - A Step-by-Step Guide for Foundation Design and Machinery Installation )..


I just want to remind some points ...

- The ( pump mass + grout mass + foundation mass ) should vibrate as a unique mass to minimize the pump vibration effects. In order to provide that , the anchor bolt shall be preloaded..

-The grout shall support the pump skid. The use of plate shims for adjustment will hinder this concept.

- You may consider the of plastic adjustment nut underside the baseplate for levelling purpose ..

- Ask to the pump manufacturer for the recommended foundation detail and installation guide..

 

[TugboatEng]

Chockfast has been the industry standard for epoxy grouting. Many other epoxy manufacturers have similar products.

 

[Artisi]

He asked for alternatives to concrete for foundation.

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.)

 

[LittleInch]

That's a decent sized pump so there is a lot of inertia here. Concrete provides a large mass to resist this quite cheaply.

Mounting such a pump on steel would require large section beams with lots of cross support to avoid any movement or twisting.

Of course you can mount pumps on steel structures like oil rigs but most people don't because it costs a lot more

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

 

[Strong]

You must have a good reason for not using concrete! Chockfast is not concrete, since it is composed of epoxy resin and aggregate. It is about 10x stronger than concrete and certainly more expensive. I used it to replace a concrfete pedestal under a turbocharger for a gas compressor engine to eliminate a vibration problem.

Assuming the motor and pump are on a steel base/skid, then there are many foundation options. Wood or steel pilings driven into ground can be used for a rigid foundation. Wood timbers and steel beams on grade, concrete or steel tanks, or elevated building structures (decks or floors) that meet static weight requirements can be considered if the base/skid is on resilient mounts (vibration isolators). Suction and discharge piping connections (rigid or flexible) and structural natural frequencies are primary design considerations.

Walt

 

[DiegoCB]

Thank you for your responses,

TugboatEng, I didn't know Chockfast, I will review that solution, thanks.

LittleInch, a pump vendor suggests an under skid that complies with some of the characteristics that you refer to, also the weight criteria that HTURKAK indicated. Maybe this solution will be studied first.

Strong, there is no good reason for not using concrete, just a client requirement for reducing carbon emissions. If the soil shows good properties maybe just compaction and leveling be required to receive the under skid that LittleInch suggests. If not steel pilings could be required.

The client's idea is "zero concrete", but maybe it would be not possible if they don't put more money to achieve it. Whatever be the final solution, it should have a good emissions/cost balance, so I think that the result tends to back to the concrete but certified as low emissions concrete, considering that the alternatives are costly.

Thank you all!!

 

[TugboatEng]

Is the problem with concrete a chemical reaction issue? If may be possible to encase the concrete foundation in fiberglass and then use epoxy grouting.

I try not to plug specific manufacturers here but ITW is the premier manufacturer of epoxy chocking and grouting products. Belzona has a few competitive products.

https://itwperformancepolymers.com/products/chockfast/

 

[Artisi]

Has the client taken the time to do an emission analysis on concrete and what ever alternate method he has mind, or is it just a nonsense idea.

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.)

 

[TugboatEng]

Oh, I see the previous post now.

Wood. Carbon is sequestered in wood. Use that. You can make your shims out of lignum vitae. This combination is good enough for some high horsepower tugboats and ships. You can make it work for your application.

 

[electricpete]

I wasn't familiar with this aspect of concrete. Googled to find this. Just posting here to save others like me from googling

https://en.wikipedia.org/wiki/Envir...e#Carbon_dioxide_emissions_and_climate_change

Environmental impact of concrete....

Carbon dioxide emissions and climate change:
[ul]
[li]The cement industry is one of the two largest producers of carbon dioxide (CO2), creating up to 8% of worldwide man-made emissions of this gas, of which 50% is from the chemical process and 40% from burning fuel.[1][4] The CO2 produced for the manufacture of structural concrete (using ~14% cement) is estimated at 410 kg/m3 (~180 kg/tonne @ density of 2.3 g/cm3) (reduced to 290 kg/m3 with 30% fly ash replacement of cement).[5] The CO2 emission from the concrete production is directly proportional to the cement content used in the concrete mix; 900 kg of CO2 are emitted for the fabrication of every ton of cement, accounting for 88% of the emissions associated with the average concrete mix.[6][7] Cement manufacture contributes greenhouse gases both directly through the production of carbon dioxide when calcium carbonate is thermally decomposed, producing lime and carbon dioxide,[8] and also through the use of energy, particularly from the combustion of fossil fuels.[/li]
[li]One area of the concrete life cycle worth noting is the fact that concrete has a very low embodied energy per unit mass. This is primarily the result of the fact that the materials used in concrete construction, such as aggregates, pozzolans, and water, are relatively plentiful and can often be drawn from local sources.[9] This means that transportation only accounts for 7% of the embodied energy of concrete, while the cement production accounts for 70%. With a total embodied energy of 1.69 GJ/tonne concrete has a lower embodied energy per unit mass than most common building material besides wood. However, concrete structures have high mass, so this comparison is not always directly relevant to decision making. It is worth noting that this value is based on mix proportions for concrete of no more than 20% fly ash. It is estimated that one percent replacement of cement with fly ash represents a .7% reduction in energy consumption. With some proposed mixes containing as much as 80% fly ash, this would represent a considerable energy saving.[7][/li]
[/ul]

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(2B)+(2B)' ?

 

[1503-44]

This is why cement plants are prime targets for carbon capture and storage. Buy cement from such a plant would not contribute to a company's carbon footprint.