Swimming pool pump 1

[Keshavsookun]

Hello everyone.

My question is about sizing of a swimming pool of nearly 50m3 capacity.

How should i calculate the pressure that should be given at delivery ports in the pool, as I am sizing the pump head.

The frictional losses i have already calculated, the dynamic losses also but I don't have the pressure at delivery that should be incorporated.

A worked example would be of great help of any specific guides.

Thanks

 

[Artisi]

Your local swimming pool pump supplier might be a good place to start considering you have supplied about 10% of the data needed.

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]

Depends if you want "jets" or just gentle flow out of the delivery ports.

But swimming pool pumps are usually pretty generic and able to work a variety of heads without damage as they are simple low power pumps.

If in doubt add 5 ft head.

Any pool pump vendor will be able to advise.

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

 

[FACS]

The capacity of your pool only determines what your flow rate will be.
The elevation on the pool means more.

My swimming pool is 30,000 gallons.
It is in-ground and the water level is 1-foot below ground level.
The pump is 1 HP and is mounted at ground level.

It has three inlets, one at 3 feet below ground level and two skimmers at water level.
It has two discharge ports into the pool, both are 2-feet below ground level.

If it is an above ground pool, most are 4-feet high. The pumping system for these is different so adding 5-feet of head as suggested isn't realistic nor necessary. That's already been figured out.

And whether you are pushing through a sand filter or fiber, adding jets and other things like cleaning booster systems, only means you will need more pump power for the push, not the head.

 

[LittleInch]

If you're coming from and going back into the same pool below the water level the elevation of the pump relative to the water level is irrelevant so long as it is less than about 25 ft as you can't lift water more than that height even when the pipe is full.

Placing the pump above the water level means you need to have either a self priming pump or non return valves, but this is not what the OP was asking.

But these pumps are very small and more like your central heating pump. I really wouldn't be getting stressed about it.

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

 

[1503-44]

Try this,

Supposedly you only have one unknown here, if you have reasonable pipe diameters.
You don't know pump head, but you can easily work that out.

You have the flow rate you want and its velocity in the discharge pipe. You can calculate the head losses for your suction and discharge lines, Start with the sum of the head loss of both pipes. Add the dynamic head of your velocity v²/(2g) plus the depth of your discharge. Subtract the depth of your intake. Add another 10% safety margin to get total head required. Now, finally, select a pump with that head for your desired flow rate.

The elevation of the pump does not matter that much, as long as the pump will self prime. Keep pump elevation minimum. Head loss going up to the pump will be gained going down to the outlet, so all that matters is the difference of depths between inlet and outlet. You have accounted for that already.

 

[LittleInch]

The difference in depth between intake and outlet is irrelevant for a closed loop system as the hydraulic head balances out.

If you connected a tube with one end 3m below water level and the other end 1m below the same water level, would there be any flow in the tube? No. So to get flow all you need to calculate is the flowing friction losses through the inlet pipe and the outlet pipe plus 10% for the exit losses.

Pumping from one pool to an different pool is different, but not the same pool.

That's why I said it's like your central heating pump, it's just pumping water around in a closed circle

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

 

[1503-44]

Maybe it is a wave pool.

But yes, with a flat water surface, correct. Even easier than I thought.