booster pumps 1

[Neel.mech]

hi,

I am struggling to determine the discharge of a booster pump , which is a part of my project.Pump is supposed to deliver the required volume at fixture outlet pressure of minimum 20 psi .i have a water storage tank of 1000 m3 (2.6 m height )capacity and using uPVC pipes..how do i have to calculate discharge of the pump in gpm? can anybody suggest me standard procedure for selecting a booster pump? i have calculated using wsfu method , client says pump capacity is high!

 

[bimr]

When using the WSFU method, the fixtures in a system are never used all at the same time, the total units achieved by adding the numbers for all fixtures must be compensated for intermittent use.

Perhaps you can provide a sketch of the system?

Did you size the pumps based on the total units?

Is your system looped back to the tank?

Why is the client stating that the flow is too high?

 

[Neel.mech]

hi ,
bimr , thnx for replying.pump is looped back into tank , i have calculated based on wsfu method.which would give me a booster pump with discharge of 386 gpm , while the client side says it can be around 140 gpm..is there any other methods i have to consider while designing booster pump capacity ? can you suggest me standard methods for booster pump sizing ....

 

[Neel.mech]

i will give you an idea about the project , i have 12 wsfu per building , which is a part of a township, consist of 320 building of same capacity so how can i calculate the exact water requirements and size a booster pump, assuming there is no elevation ...

 

[bimr]

This scenario is complicated because of the probability of each user to access the water at the same time. At night, the flow will be almost nothing. The water flow to each residence is generally based on the socioeconomics of the residences as well as the yard watering demand.

If you look at textbooks (Fair & Guyer for example), the peak hourly flow will be approximately 10X the average daily flow. This ratio is based on empirical population studies of water systems.

These types of system with large flow variations are usually handled with VFD's on the pump motors so that the capacity may be reduced. By tracking pressure, flow or electrical current, a variable speed booster pump can deliver constant pressure at any flow rate.

Review the links for the particulars. These systems are similar to the booster pump systems for high rise buildings which have been written up in trade journals.

https://www.taco-hvac.com/images/boost.pdf

http://www.asse-plumbing.org/Articl...ses to the Top of Skyscrapers- Octo-Dec05.pdf

 

[Neel.mech]

thnx, bimr..i will consider your advice , and check what type of booster pump client want to install ...

 

[fopoku2k2]

basilbn . . . where you able to calculate for the required capacity of the booster pump??

I have a similar design problem. My design consist of 18 two storey apartments. Each apartment has 4 washrooms (water closet + wash hand basin + shower), 2 kitchens and 1 washing machine.

I'm trying to size a booster pump to boost water from a break tank to all the apartments.

Thank you

 

[bimr]

fopoku2k2

You have to determine what building code the AHJ has adopted. Once you have determined the code requirements, then you can proceed to estimate the water supply requirement.

Attached is an outline of the methods that are used to estimate the water demand.

There is one note in the table that shows each Apartment, multiple family (per resident) is 50 GPD (note this is not peak demand).